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close this bookObsolete Pesticides - A Dangerous Legacy - Results of a Pilot Project on the Disposal of Obsolete Pesticides (GTZ, 1999, 52 p.)
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Deutsche Gesellschaft fhnische Zusammenarbeit (GTZ) GmbH

Published by:

Deutsche Gesellschaft
fhnische Zusammenarbeit (GTZ) GmbH

Text: Wolfgang A. Schimpf, Doris G, Bernd Eusemann


Lorenz Translations, Trier

GTZ Language Service, Eschborn

Photos: Wolfgang A. Schimpf

Concept and realization: Bernd Eusemann, Ihringen

Layout: Till Eusemann

Printed by Vollmer + End, Kappel-Grafenhausen


In many countries of Asia and Africa, Latin America and even Europe, rotten drums of old pesticides can be found lying around in totally inadequate storage facilities. Once supplied in large quantities, they somehow never got used and eventually slipped into oblivion. No one knows their exact quantities, and some of the storage sites would be difficult to locate. There can be no doubt, though, that some of the agents and preparations found stored under precarious conditions are extremely toxic and therefore pose a major hazard for people and the environment. Some such sites are situated right in the middle of densely populated cities. In many places, the contents of thoroughly corroded drums have already leaked into the ground and, in some cases, penetrated the groundwater table.

Numerous inquiries from emerging nations document the scale of the problem. Quick to recognize the volatility of the situation, BMZ commissioned GTZ in 1991 to conduct a pilot project on the disposal of obsolete pesticides. Since then, the disposal of overaged pesticides has evolved into an independent, very extensive range of activity within the field of technical cooperation.

From a development-policy standpoint, the main idea from the very start was to learn from past mistakes for future reference. Global attribution of responsibility (= finger-pointing) would be both out-of-place and counterproductive. Conversely, all concerned have had to accept their respective measures of co-responsibility and that has served as a point of departure both for elaborating problem-solving strategies and for working together to avoid new hazardous waste problems. Worthy of particular emphasis in that connection is the close, fruitful cooperation between BMZ/GTZ, the FAO and the plant protectant producing industry. The same applies to the energetic commitment of our partners in emerging nations.

Between 1991 and 1999, GTZ s Pesticide Disposal Project implemented 25 individual measures, gradually developing a general strategy for future tasks. This booklet outlines the broad spectrum of those project activities, analyzes their respective backgrounds and problem causalities, reviews the various approaches for solving such problems, and probes some future perspectives. The main focus is clearly centered on the practical experience gained from the work. Examples of particularly successful country measures are presented: Zambia, for example, has become the first country in Africa to rid itself of obsolete pesticides. The benefits for others are highlighted by way of cases in which GTZ has pioneered various technical and/or organizational aspects including some very remarkable new forms of cooperation in which pesticide producers become financially involved in the projects. The maturity of the described options makes them suitable for recommendation as models for other actors, too.

Bonn, December 1999

Dr. H.-J. de Haas
German Federal Ministry for Economic Cooperation and Development (BMZ)

Dr. C. Henckes
OE 4541
Deutsche Gesellschaft fhnische Zusammenarbeit (GTZ) GmbH

From Active Agent to Hazardous Waste

More than 100,000 tons of obsolete pesticides in developing countries must be disposed of.

Madagascar, February 1991

The scene was unsettling: over 200 rotten, rusty, leaky drums of dieldrin - over 47,000 liters in all - were found scattered across a large area in the southern part of the island. The pesticides stockpiled at the government-operated Plant Protection Service store were found to be dripping out of the rusted-through drums and seeping into the ground. Safe local disposal had to be ruled out, so all 47 tons of pesticide were transferred to Great Britain for ultimate disposal in a special high-temperature incinerator.

Mauritania, September 1997

Throughout the country, at all strategically important points, there are storage sites containing large amounts of insecticides for use the next time the country is plagued with swarms of locusts. The results of an inventory conducted in 1993 documented some 200,000 liters of dieldrin, some of which was stored in leaky drums. Near Ayoun al Atrous, more than 78,000 liters of the pest killer jeopardized the wells from which the people got their drinking water. Consequently, in 1994, the contents of the most badly corroded drums were refilled into new containers as an initial remedial step. Then, in September 1997, the entire remaining stock of dieldrin was taken to the Netherlands and incinerated.

Two different countries and two extreme examples, but one and the same substance. And no end in sight, because what s in a name? The countries involved could just as well have been Mali and Zambia, Tanzania and Mozambique, or Nicaragua and Pakistan. And the substance in question is not always dieldrin. Plenty of other pesticides also have quietly emerged as troublemakers in the course of time.

And the worst of it is that no one knows for sure how bad the problem really is. According to FAO estimates, some 20,000 tons of obsolete pesticides, i.e., plant protection agents that can no longer be used, are lying around various parts of Africa. And that is probably an understatement. Also, while the problem is particularly conspicuous in African countries, it is by no means confined to that particular continent.

All non-OECD countries together are believed to have more than 100,000 tons of obsolete pesticides in storage, largely in Africa, Asia, Central and South America. Even Europe has its pesticide problems. The former German Democratic Republic (GDR), for example, which was a major exporter of pesticides, sent a consignment of such products to Albania in 1992. Since the goods were being donated to Albania by a company in West Germany, it was a fully legal transaction. Then, as the government in Tirana realized what kind of “gift” they had received, the traceable remainder of 460 tons of pesticides had to be declared obsolete - and that made headlines. A large proportion of the 100 or so agents supplied in this way were no longer serviceable. Seventeen of them contained active ingredients that were already banned for use in the Federal Republic of Germany, including, for example, camphechlor and various compounds of mercury.

Dieldrin for example

Dieldrin is the trade name for a broad-spectrum insecticide, 85% of which consists of the agent HEOD. This organochlorine (= chlorinated hydrocarbon) compound was discovered in the 1940s and produced by Shell International Ltd. in the Netherlands and the United States. It is a highly toxic insecticide which the World Health Organization assigned to the hazard category I b (highly hazardous). It accumulates in the food chain and is characterized by high persistence. It is suspected of having carcinogenic effects on humans, though this has not yet been confirmed.

For over 20 years, dieldrin was in widespread use in the farming sector, as a wood preservative, and in the fight against malaria, river blindness and the tsetse fly. Dieldrin was one of the most effective insecticides available. It was even recommended by the FAO for use as a locust control agent. Dieldrin was banned in the Federal Republic of Germany in 1971, and the USA prohibited its use in agriculture and practically all other areas of application in 1974. Since then, other countries have done likewise, particularly as new, less toxic, less persistent agents became available. By 1977, Shell had scaled back its dieldrin production volume by one-half, and then discontinued it altogether in 1987.


4,6 dinitro-o-cresol (DNOC) is an aromatic nitro compound with insecticidal, herbicidal and acaricidal properties. Over 40 years ago, it was one of the first pesticides to be produced on a large scale, initially by Bayer AG, but later on by many companies around the world. Thanks to its long shelf life, it was very well-suited for use as a strategic insecticide for locust control in tropical zones. DNOC was produced and applied in all types of formulations but was most frequently dissolved in petroleum.

DNOC is listed in the WHO hazard category I b (highly hazardous). It can be absorbed through intact skin and assimilated/ingested via the lungs and the gastrointestinal tract. Acute and chronic intoxication manifests itself in damage to the heart, liver and kidneys and in irritation of the eyes and respiratory organs. DNOC shows a strong tendency to accumulate in the blood, eventually leading to death. DNOC is also believed to have mutagenic effects.

Being readily soluble in water, DNOC is highly mobile. In a body of water, it proves highly resistant to microbiological and physicochemical transformation reactions. In soil, however, it is subject to rapid microbiological decomposition. DNOC has been supplanted by more effective, less toxic pesticides. However, residual inventories of DNOC can still be found in numerous Third World storage facilities.


Dimethoate is a stomach/contact insecticide and acaricide for use against numerous different pests. Chemically, it is an organophosphorus compound. It is made and marketed around the world under various trade names and formulations by a number of companies.

Dimethoate has been assigned to the WHO hazard category II as moderately hazardous. It is suspected of causing damage to the nervous system and of irritating the eyes and skin. In-vivo oxidation produces dimethoate oxone, an acutely toxic isomer with a strongly inhibiting effect on cholinesterase. Dimethoate oxone appears to be more persistent than dimethoate itself.

Organophosphorus compounds hydrolyze quickly in alkaline media. They are thermally very unstable. At temperatures above 60°C they begin to disintegrate into a series of reaction products (isomers), some of which are more toxic than the original product. Thus, when organophosphorus compounds are stored under unsuitable conditions at the kind of high temperatures that are frequently encountered in developing countries, they break down rapidly and become unfit for use. That is why organophosphorus compounds account for a relatively large share of obsolete pesticide stocks in developing countries.

Pakistan: Origin of pesticide stocks according to an inventory from the Punjab Province

Thus, an initial resumould read: immense quantities of old pesticides are still to be found in stores all around the globe. Only some of the precise quantities and locations are even known, and the extent of the potential hazard to humans and the environment can only be guessed at. We are dealing here not with any particular agent, but a broad range of them - some of them unfit for use and others prohibited from use: pesticides have become hazardous waste.

These things went on for a long time - ten years or more - during which surplus pesticides were laid aside, often in completely unsuitable storage facilities with no protection against the elements, in containers that had already been treated roughly on their way there.

As time passed, the chemicals gradually decomposed. In the course of such decomposition processes, which defy manipulation, highly toxic decomposition products can form. The agent s effects become unpredictable. What eventually remains is a poisonous substance that amounts to a potential hazard. And so, the economic loss evolves into an ecological problem as well.

There are many reasons why pesticides are left lying around for such a long time. The most frequent case is that of strategic stores of pesticides being saved up for sudden calamities like swarms of locusts. Then, if fewer of the pests turn up than expected - or none at all - there is no reason to bring out the pesticides.

Various other well-meant aid deliveries also ended up in indefinite storage because they simply did not fit the requirements.

In the absence of reliable inventory data, records of disposition and consumption prognoses, selective procurement was practically impossible. Often enough, either the wrong pesticides were delivered or the formulations precluded the agents optimal application. Unsuitable containers and inadequate labeling made the users unsure of themselves, so they left the pesticides lying where they found them. There were also cases in which a partial or total lack of quality control led to developing countries receiving substandard pesticides. Wars, which tend to cause drastic downturns in production, also have negative effects on pesticide consumption. Consequently, large stocks of pesticides are left behind and forgotten at abandoned storage sites.

One change of course that was effected with the best of intentions had unanticipated consequences: For quite some time, together with such other organochlorine compounds as aldrin, endrin, DDT and BHC, dieldrin was the standard insecticide for use against locusts, particularly in emerging African countries. Once a range of less persistent, less toxic alternatives became available, however, the United States Agency for International Development (USAID) made all further technical assistance contingent upon abstention from the use of “drins”. Other donors followed suit, and the pesticides in question became obsolete and had to be disposed of. What those responsible for the ban had neglected to consider was that large quantities of these agents, dieldrin in particular, were still in store all over the world, and no transition period was allowed.

Thus, the transition from pesticide to hazardous waste takes place for many reasons, some of which are of much more consequence than others. Naturally, if no one had ever bought any pesticides, none would have to be disposed of. And without the efforts of numerous donors, there never could have been such a massive accumulation of old stocks. Industry, too, has been repeatedly criticized. The producers and suppliers of pesticides have been accused of contributing toward the pointless accumulation of pesticides through their excessively aggressive product marketing activities.

Donors, governments, industry - all have contributed to the dilemma. As such, it would make no sense to point the finger at any one in particular. What would help, though, would be for all those concerned to accept their own responsibility for the problem and then search for solutions together. This should not be perceived as a call to simply atone for past sins; the idea is to also make provisions for the future.

Not all actors always own up to their joint responsibility. More than one project has been frustrated by a lack of pertinent willingness on the part of competent authorities in the countries in question before the concrete phase was ever reached. Conversely, there have been other, very successful cases of cooperation that can stand as examples for future work. Why? Because all concerned learnt lessons from their past mistakes.

Morocco: Donors, governments and industry have all contributed to the dilemma.

From Hazardous Waste to Problem Solver

Malaysia: The incineration of pesticides in a rotary kiln is one safe method of disposal.

The chemicals sector has enjoyed consistently high growth rates in production and international trade volumes since the 1960s. Worrisome is the fact that chemical products are being exported to countries which lack the preconditions for proper registration and for the safe application of such substances.

Indeed, not only the chemicals themselves enter circulation. The production processes and the chemicals’ life cycles are attended by large quantities of highly toxic waste. Even hazardous wastes are preferentially shipped off to countries that have not yet adopted laws with which to protect themselves.

Periodical scandals cast a harsh light on how chemicals are handled. Health hazards and environmental issues are attracting more and more of the public’s attention, and that has been instrumental to the emergence of legal prescriptions that regulate the buying, selling and application of hazardous chemicals and the disposal of toxic waste.

Regarding the safe buying, selling and handling of pesticides, diverse agreements have been reached, e.g., the International Code of Conduct on the Distribution and Use of Pesticides, the International Convention on the PIC (Prior Informed Consent) Procedure, and the Basel Convention.

GTZ was early to realize the problem potential of obsolete pesticides. As early as the mid-1980s, before the Pesticide Disposal Project was even conceived, the Malaysian-German plant protection project conducted some initial experimental trials concerning the disposal, in a developing country, of old pesticides that were no longer fit for use. In a technically sophisticated cement factory near Kuala Lumpur, small quantities of obsolete pesticides were successfully incinerated.


Soon after its launching in 1984, the Malaysian-German pesticides project encountered some obsolete pesticides that had to be dealt with. The rotary kiln at a cement factory in Rawang near Kuala Lumpur presented itself as a pragmatic solution. The factory’s managers supported the project and agreed to a series of incinerating trials.

At first, in 1985 and 1986, a number of trials were run with small amounts of liquid waste. Then, in 1987, the cement kiln was loaded with 70 kg of herbicidal residue with a theoretical chlorine content of 13.2 kg and a 2, 3, 7, 8 TCDD content of less than 1 µg/kg. Dust samples taken from the filter before and during the incineration process showed that burning the herbicide apparently had no effect on the average chlorine content of the precipitated dust, and it contained no detectable PCDD/PCDF isomers.

In an experiment conducted around mid-1989, substantial quantities of liquid and solid pesticides were incinerated, including such organochlorine compounds as lindane, DDT and endosulfane. Flue gas monitoring documented that the chlorine, hydrogen chloride and phosgene levels were situated within the acceptable emission limits for industrial stack gases in Malaysia. Even the elevated chlorine content of the cement clinker remained well within the permissible maximum concentration.

These trials inferred that the incineration of such organic compounds as pesticides in rotary kilns is both feasible and safe. The findings presented in 1987 at a conference in Pattaya, Thailand, were very well-received. Soon, a number of national development agencies and such international organizations as UNDP, FAO and WHO began to promote the technique.

Legal framework

Obsolete pesticides are agrochemicals, the further use of which is neither possible nor permissible. They are regarded as hazardous waste and must be properly handled and disposed of in accordance with national and international regulations and directives.

Basel Convention

The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal stems from a 1981 initiative in reaction to the mounting number of illegal transboundary movements of waste to countries of the Third World, where serious environmental damage was feared. The convention was adopted in 1989 and entered into force in 1992. In the meantime, this international agreement has been ratified by more than 100 countries and the European Union, all of which pledge therein to afford first priority to the avoidance of hazardous waste. Where that is not possible, such waste is to be eliminated at its place of origin. In 1994, the export of hazardous waste from OECD countries to non-OECD countries for purposes of disposal was banned as of immediately. A corresponding ban on the recycling of hazardous waste came into force in 1997. Ex-country disposal is only permitted on exception, primarily for cases in which the country itself has no suitable disposal facilities. In such cases, industrialized countries assure developing countries the provision of technical assistance.

Regarding the transboundary movement of hazardous waste, the Basel Convention prescribes the notification procedure which must be precisely adhered to by the exporting country, the importing country and all potential transit countries (states of transit). All countries involved must be party to the Basel Convention; otherwise, bilateral agreements are necessary.

Bamako Convention

Adopted in 1991, the Bamako Convention is an adaptation of the Basel Convention to the African situation. Signed by nearly all countries of Africa, it includes a ban on the importation of hazardous waste to Africa and prescribes the supervision of transboundary movements.

Prior Informed Consent (PIC)

The 1998 Rotterdam Convention on the Prior Informed Consent (PIC) Procedure for Certain Hazardous Chemicals and Pesticides in International Trade came about in reaction to the broadening of international trade in toxic chemicals and its consequential problems, most notably in developing nations. Its prime objective is to help protect countries which do not yet have adequate means of import monitoring, management and infrastructure.

According to the PIC procedure, exporting countries pledge to inform the importing countries about the intended transport of certain hazardous chemicals and to approve such exports only with the prior express consent of the importing country (Prior Informed Consent).

A chemical is deemed hazardous if its use in a PIC signature country is either banned or severely restricted for reasons pertaining exclusively to its effects on human health or the environment. The same applies to certain pesticide formulations, the toxicity of which causes health problems if they are used under suboptimal conditions - which often prevail in developing countries.

The aim of the PIC procedure is to disseminate information on the risks and hazards involved in the transportation, distribution and application of such chemicals. It therefore serves as a decision guidance document for use by the importing countries. At present, the PIC procedure is being applied to 22 pesticides and five industrial chemicals.

List of pesticides that have been made subject to the PIC procedure (Status: March 1998)

Dinoseb and salts of dinoseb
Ethylene dibromide (1,2 dibromoethane)
HCH (technical)
Inorganic and organic mercury compounds
2, 4, 5 T

In addition certain formulations of:

Methyl parathion

LD50 for rat (mg/kg body weight)








Ia Extremely hazardous

5 or less

20 or less

10 or less

40 or less

Ib Highly hazardous

5 to 50

20 to 200

10 to 100

40 or less

II Moderately hazardous

50 to 500

200 to 2000

100 to 1000

400 to 4000

III Slightly hazardous

over 500

over 2000

over 1000

over 4000

Pesticides are classified according to acute lethal dose.

This approach to the elimination of highly toxic waste was a logical choice: to this day, experts regard the thermal disposal of organic chemicals as one of the safest, most practical options available. Moreover, numerous developing countries have the requisite, suitable cement factories.

The findings from these experiments indicate that the safe thermal disposal of pesticides is, in principle, possible in developing countries. Of course, each case depends on the type of waste to be incinerated and which level of technical standards the cement factory satisfies: pesticides containing large amounts of halogens or heavy metals, as well as inorganic compounds, are unsuitable for incineration. Likewise, not all cement factories can be adapted at reasonable cost. Chapter 5 will deal with these matters in more detail.

Following those initial experiments in Malaysia, several years passed before GTZ set up a special pesticides disposal section. Meanwhile, relevant problem awareness was waxing noticeably in developing countries. Then, at the Basel Convention, the industrialized countries pledged to help developing countries manage their hazardous wastes. Finally, the United Nations’ Agenda 21 also expressly promoted international cooperation in the field of hazardous waste management.

After that, one developing nation after another sought concrete assistance for disposing of their old pesticides. The German Federal Ministry for Economic Cooperation and Development (BMZ) therefore launched a pilot project dedicated to collecting and portraying experience relevant to the new field of activity.

Between 1990 and 1999, the “Pilot Project on Pesticides Disposal” devised concepts and procedures for the disposal of old pesticides, containers and cleaning of contaminated storage sites in developing countries. This concerned not only the relevant technology and administrative procedures, but also systematic, cooperative problem solutions. The chief aim is for decision makers and partner country specialists to acquire know-how that will be of use to them for other waste management tasks as well. Countries with similar problems, it is hoped, will also profit from the experience gained via this pilot project.

Twenty-five individual measures were completed in the course of the project term. It was not possible to satisfy all inquiries, since the demand was too heavy for the available amount of funding. Consequently, an applicant selection process had to be instituted on the basis of criteria geared both to the pilot character of the project and to development-policy principles.

First of all, the problem relevance and the hazard potential had to justify intervention. Organochlorine compounds, for example, account for a substantial share of the overall old-pesticide incidence and therefore constitute a problem for many different countries. By now, the application of such substances has been either banned altogether or severely restricted in nearly all countries out of concern for human health and the environment. The hazard potential of other substances has less to do with their persistence than with their acute toxicity. In general, the hazard potential is all the greater, the more likely it is that the substances will come into contact with people and the environment.

Also, it was deemed necessary to demonstrate on a model basis the various local disposal options. According to the Basel Convention, the exporting of hazardous waste remains an exception that is only justifiable if no suitable local facilities are available at the place of origin. Thus, the long-term establishment of local disposal facilities is of key importance.

The chances for success also counted among the selection criteria. The project gave preference to cases in which the prospects for cooperative solutions were the greatest. Partners who recognize their own co-responsibility play a more active role in finding solutions to their problems and are more likely to cope successfully with the kind of difficulties that are always encountered in connection with waste management measures. This applies in like manner to the competent authorities in the developing countries and to pesticide producers, a number of whom have participated in successful cooperative programs.

Finally, the partner countries’ willingness to practice prevention was an indispensable prerequisite for the provision of assistance. Waste management is laborious, risky and expensive, for which reason it is seen as a unique element of development cooperation. Within the partner countries, mechanisms with the capacity to effectively prevent the further occurrence of problem waste must “take hold”: legislatural measures, for example, and up-to-date licensing criteria, quality assurance and deployment checks, reformation of the procurement system, improved storage and transport management, etc.

Albania: Leaking pesticide containers are a hazard for the environment. (1)

Albania: Leaking pesticide containers are a hazard for the environment. (2)

Zambia: Cleaning up a Country

Zambia: To avoid pesticide washout special safety precautions are necessary.

Water-engineering experts from GTZ encountered a dilemma while working on a water supply project for the capital city of Lusaka. What they found in the city’s industrial district was chaotic: A plant protectant store belonging to a farm cooperative was situated a mere 700 meters away from a potable-water well. The place was littered with hundreds of rusty, leaky drums, mountains of rotten bags and broken bottles. At first, the full extent of the problem defied recognition. Apparently, however, rain water had already washed some of the pesticides out of their dilapidated containers and into the ground.

Undertaking a systematic survey of the area, the Pesticide Disposal Project team found the situation to be as follows: The plant protection products from the original drums and bags had since become thoroughly mixed. The analysis documented the presence of eight different substances, including atrazine, DDT and lindane. All these substances were found in soil samples, and water from the well contained traces of atrazine. This alarmed the competent authorities, who took initial measures to protect the water. The well was shut down and the store covered with tarpaulins to prevent any further washout of pesticides.

In the course of their joint mission in 1995, GTZ and FAO estimated the total weight of the solid plant protectants and the empty containers at over 300 tons. In addition to the Lusaka site, uncontrolled “dumps” were also discovered at nine other up-country locations.

As stated in the Environmental Protection and Pollution Control Act of 1990, the Environmental Council of Zambia (ECZ) is responsible for toxic chemicals. Before that, the Central Statistical Office, the Agro-chemicals Association and various other entities, whose data provided a starting point for the subsequent survey, had also been concerned with the sector.

ECZ studied the effects of international agreements on the use of such chemicals in Zambia. The first objective was to identify the substances that had been in use in Zambia in the past. The study was also intended to help identify the main importers, exporters and users and to establish both the areas in which the prior informed consent (PIC) procedure comes to bear and how the consumption of chemicals affects the environment. Then, ECZ and FAO conducted a second survey with the aim of mapping the whereabouts of obsolete pesticides and their respective quantities.

Thus, three partners had joined forces in order to dispose of the toxic “legacy” in line with international standards: ECZ, FAO and the Pesticide Disposal Project of the GTZ.

A memorandum of understanding supplied the legal framework of cooperation. It called for the drafting of a mutually acceptable plan of operations, defined each partner’s responsibilities, and embodied agreements concerning preventive measures. The latter consisted mainly of holding training courses for Zambian experts in order to establish a well-functioning pesticides management setup and to prevent the occurrence of new baseline pollution.

Removed Pesticides and Sanitized Stores


more than 300 tons of a mixture of HCH, DDT, lindane, atrazine and other pesticides


35 tons of DDT and contaminated soil, diazinone and endosulfane


18 tons of dinitro-o-cresol (DNOC), and contaminated containers


21 tons of diverse pesticides, 37 different agents in all


1 ton of MCPA and others, ethylene dibromide (EDB)

Zambia: A pesticide dump in Lusaka was situated close to a potable-water well.(1)

Zambia: A pesticide dump in Lusaka was situated close to a potable-water well.(2)

Zambia: A pesticide dump in Lusaka was situated close to a potable-water well.(3)

Since Zambia lacked suitable facilities for effecting disposal of the obsolete pesticides, the only possibility was to dispose of them in a special high-temperature incinerating plant in Europe. And so, the unpredictable freight rolled along nearly 2,000 km of railroad tracks to Dar-es-Salaam on the east coast of Africa. From there it was shipped around the Cape of Good Hope to Great Britain, where Rechem International Ltd. - a reputable commercial disposer of problem waste - was entrusted with its incineration.

Naturally, not all aspects of such a complicated scheme can be expected to run smoothly. For example, delays were caused by two occurrences: the containers with the required equipment arrived late due to customs checks that thwarted their quick passage from South Africa to Zambia via Zimbabwe. Further delays were caused by unabating heavy rains. Also, local newspaper reports about goings-on with obsolete pesticides sometimes missed their mark and, hence, caused some confusion.

Despite all adversities, however, the operation was successful. By the end of April 1997, the US $ 1.1-million, FAO-managed measure had removed 360 tons of obsolete pesticides from Zambia. Thus, the original estimate had even been exceeded. One reason for this was that the local radio stations had aired appeals for the people to turn in their old pesticides at certain collection points, and the people had responded in large numbers.

Operation Zambia was not only the largest single measure of its kind ever to have been conducted in Africa. It also made history in another way: Zambia now counts as the first developing country to be completely rid of obsolete pesticides

How to Gain Insight

Zambia: Sampling and analysis of potable water constitute an integral part of surveys and risk assessments.

As long as the scale of a problem is unknown, the problem cannot be solved. Consequently, the first step of any remedial measure must consist of stocktaking in the form of an inventory. Two different kinds of data are gathered according to a standardized method. One set of data pertains to the condition of the store itself, and the other documents that of the store’s contents. Together, these data illustrate the scale of the problem. Supplementary photographic documentation is advisable.

Information about the general condition and infrastructure of the store must be gathered, and the ownership / possessory situation, the workers’ level of training, the location and size of the site and/or buildings must all be clarified. Important aspects include the store’s proximity to open waters or residential areas; rain percolation potential; and soil contamination. The quantities of pesticides currently in storage must be determined and the condition of their containers ascertained. Their contents have to be estimated, sampled and compared with the inventory lists. Any site that is confusingly organized or complicated in structure will require the drafting of supplementary site plans showing the exact locations of the individual products.

With the inventory serving as a reference framework, the reason(s) why the products were not consumed should be inquired into. This will yield information about where preventive measures need to be taken.

The data aggregate should be as precise as possible, for it will have to serve as a decision-making basis. A simple rough estimate of stocks on hand, or the incomplete identification of the store’s contents, can be extremely hindersome, both in the technical-administrative and in the financial sense. For example, a decision in favor of a particular avenue of disposal and a specification of required material (drums, pumps, protective equipment, etc.) will all depend on which substances are involved.

The Chemical Store Inventory

By definition, the inventory must cover:

- potentially obsolete stocks, i.e., products that were shelved more than two years previously;

- products which by force of law are no longer permitted for use, and/or substances, the use of which FAO no longer recommends;

- information concerning the products’ origins and ownership;

- unknown products;

- the respective containers;

- information about the condition and infrastructure of the site.

The data aggregate and the chemicophysical analyses of samples are obtained/conducted according to standardized methods in certified analytical laboratories. Once the material has been evaluated, the products can be quantified according to fitness for use or need for disposal. The task scope also includes an immediate assessment of potential risks and a calculation of how expensive follow-up measures will be.

Commercial waste-management companies require facts and figures upon which to base their proposals. Any operation in which such substances are hauled across country or shipped by water constitutes a hazardous-material transport, for which accompanying documents are required. These documents must, for safety reasons, define and declare the exact nature of the waste. Moreover, potential donors are more likely to become involved if they needn’t fear unpleasant surprises.

All this speaks in favor of a very carefully executed survey. There is no getting around a reconnaissance visit to the site. No one should attempt to gather information by way of questionnaires or by touring a “representative number” of sites and then drawing conclusions about the others.

Two Data Aggregates Equal One Inventory

Pesticide data

Site data

Types and quantities of pesticides

Inspection of site and suspicious areas

Types, quantities and condition of containers and their labeling

Abbreviated history of the site and its present/future use

Sampling, chemical and physical analysis

Sampling (soil, air, water), chemical analysis

Origin and reason for nonuse

Geological and hydrological situation



If no countrywide survey can be made all at once, it will have to be attended to in multiple steps that begin in one region and gradually expand to encompass additional regions.

The size of the country, the number of sites, and the distances between them - as well as the available budget - decide the size of the team. Ideally, a team should consist of three persons, usually headed by a chemist, who survey all the storage areas together. This ensures uniform procedures, both in filling out the survey sheets and in connection with sampling, thus minimizing the error rate. If such an ideal methodical approach cannot be taken, several teams will have to work simultaneously in various parts of the country.

Theoretical and practical training familiarizes all members of the team with the objectives of their endeavors and with the field environment of data capture and sampling. Effective personal protective equipment and adequate instruction in work safety are of particular importance, since it can be dangerous to even enter such a site. Thus, all members of all teams must know exactly how to protect themselves and what to do in an emergency.

Upon completion of the survey, the data aggregate has to be analyzed, particularly with respect to what should be done with the remaining stock. The chemicophysical analyses are a major factor in this respect. Normally, the agents are both qualitatively and quantitatively defined and the quality of formulation determined, because the active agent in a pesticide that has been in store for a long time may still range within tolerance, while the pesticide itself has become unfit for use, because its formulation no longer meets requirements.

Zambia: Taking soil samples is essential for risk assessment. (1)

Zambia: Taking soil samples is essential for risk assessment. (2)

Thus, the results of analysis dictate what has to be disposed of, if anything. The basic principle reads: As-intended use is the best form of disposal.

That is not to be deemed a simple frame of action; it is more like the project’s philosophy. It is one thing to view old, perhaps unidentified products primarily as potential waste, and it is something entirely different to see them as potentially useful products, once they have been repackaged and provided with new labels. Consequently, all sizable batches of inventoried products are sampled as a matter of principle.

This is only natural for unlabeled products of unknown composition and for products of doubtful quality. Even products which definitely are not supposed to be destroyed, no matter what their quality, have to be sampled and analyzed in order to confirm their identity.

To use or not to use; to destroy or not to destroy - all the project can do is make recommendations, while the final decision remains with the responsible authorities in the partner country. Once that decision has been made, however, priorities fall into place. Consequently, the survey must include a risk assessment based on the topical results of inspection and data capture.

If that assessment reveals acute risks for the local environment or for people living near the site, the necessary safety measures must be initiated at once. For example, this would be the case if escaping pesticides were posing an immediate threat to the soil or groundwater. Even refilling the material into used containers can amount to a very effective initial measure. Old oil or pesticide drums that can later be replaced with the requisite shipping containers are good enough for that purpose.

Zambia: Immediate action is necessary before the rainy season starts.

Additional safeguards include protection of the store against the effects of weather, unauthorized access and theft. Other immediate threats can be countered by liquidating uncontrolled pesticide dumps/storage sites in the vicinity of residential areas and transferring the waste to a suitable interim storage area.

Such measures gain time, and experience shows that time is valuable: Frequently, it can take up to two years before a particular disposal option is decided on, its funding assured, and the administrative prerequisites created.

An evaluation of the inspection findings and an analysis of the aggregate information determine the course of the disposal measure. The question of where the greatest risk for people and the environment is located constitutes a central criterion.

The risk is defined by the (potential) extent of damage and by the probability of that damage actually occurring: The more toxic and mobile an agent is, and the greater the likelihood that humans, animals and their environment will be contaminated, e.g., by the effects of leaky containers, the greater the risk.

Thus, product-specific parameters like toxicity, solubility and flammability have to be referred back to the conditions of storage. This yields a risk-potential-based priority sequence for the cleanup of pesticide storage sites.


A pesticide is obsolete if:

- its use is prohibited in the country in question;

- its use cannot be recommended due to health hazards or imperilment of the environment;

- it no longer satisfies minimum quality requirements (FAO tolerance guidelines for formulated pesticide products).

Albania: Sidetracked Pesticides

In the Balkans, the project encountered some German-German peculiarities: During Albania’s political transition period in 1991 and 1992, the government received a “gift” of more than 460 tons of plant protection products from a German company. The pesticides stemmed from old GDR stocks. As an investigation by the Hanover public prosecutor’s office later confirmed, this was all very legal.

The new government in Tirana requested of the German government in 1992 that the pesticides be taken back, because Albania did not need them.

So, in the summer of 1993, a mixed delegation of experts acting on behalf of the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety traveled to Albania to investigate the situation and conduct an inventory. The team was also supposed to explore the options for disposing of the pesticides in Albania. The delegation inspected five sites and a “German State Railroad train”, the latter containing 217 tons of pesticides. The inspection revealed no considerable differences between the officially stated quantities and those actually found. Some 375 tons of pesticides were sampled, but another 85 tons in all were stored in lesser amounts at numerous small stores, only two of which could be visited because of the team’s tight schedule.

The experts’ attention soon centered on the “German State Railroad train” at the Bajze border station. Seventeen goods wagons were found parked on a hill at the Montenegrin border station, a mere 3 km from Shkodra Lake, and there was no way to move them. Due to the embargo, the rail connection to Montenegro was closed, and violent storms had destroyed the upcountry tracks.

The cars were full of pesticides in total disorder - and in flagrant disregard of valid international regulations governing the rail transport of hazardous goods. Every sheet steel drum in the entire train was rusty, and large, black stains underneath the cars attested to leakage. Seven tons of delicia emulsion were found in simple 25-liter demi-johns with no more protection against breakage than ordinary wicker jackets like those used on most cider jugs. Delicia emulsion contains 50% camphechlor (technically chlorinated camphene - toxaphene), dissolved in petroleum. Any breakage not only would probably have killed the fish in the nearby lake, but also caused a fire that soon would have spread to engulf the rest of the train, as well.

Chemicophysical analysis of the samples showed that there were 43 different products with 40 different active ingredients on the train. Eleven of those pesticides were either fully prohibited or strictly limited for use by European Union directives. Twelve of the products had been approved for use in the GDR, but not in the Federal Republic of Germany (FRG). Their application was only permissible during a transition period that would terminate at the end of 1994, as dictated by Germany’s reunification agreement. For a few products, the experts recommended further use, but Albania refused: Following privatization of the country’s state-owned farms, the average size of an Albanian farm had shrunk to 1.5 hectares. The rate of pesticide consumption declined drastically, due in part to the unreliable price structure for agricultural produce. Thus, the containers were too large for the potential new users, who were also unfamiliar with most of the pesticides. Consequently, the experts recommended that the train’s entire inventory be safeguarded without delay and transferred to Germany for destruction, because Albania had no suitable disposal facilities.

Albania: The railway wagons were full of pesticides.

The Albanian government’s insistence that the pesticides be returned to Germany, plus the symbolic redemption of one ton by Greenpeace, turned the old waste into an expanding political affair. Finally, in 1994, the pesticides were taken to Germany and disposed of - at a cost of DM 7 million.

The delegation made revealing discoveries at other sites, too. In addition to leaky drums and burst bags, they found large quantities of new, perfectly well-packaged plant protection products that had been brought into the country after 1991 by the European Union (EU), the World Bank and diverse manufacturers. These agents, the delegation found, had been put in store and never used. If this is allowed to run its course, the next candidates for disposal are already in the offing.

Mozambique: A Civil-War Legacy

Mozambique: Redrumming is a first step to prepare leaky drums for transport.

Through most of the 1990s this southern African country remained a focus of interest. The project’s first local encounter with obsolete pesticides there was in 1992, when hundreds of empty containers were found stacked in a closed-down Shell pesticide formulating plant, along with 70,000 liters of azodrine/DDT and 80-plus tons of contaminated soil, all in metal drums.

And this was only an interim storage site. In September 1990, namely, Shell International Ltd. had undertaken a safeguarding and cleanup operation, in the course of which the agents had been filled into new drums and stored in old containers on the premises of the Maputo formulating plant. Before that, they had spent at least 15 years at the government-operated pesticides depot in Beira. The operation was necessary, because the insecticide was threatening to dribble into the Bay of Beira and wipe out its entire fish stock.

At the request of Mozambique, the German government helped dispose of the waste. As it became apparent that the azodrine/DDT in question was not the only unwanted stock of plant protectants in Mozambique, the project expanded its activities to include a countrywide survey.

In early November 1994 the last containers full of obsolete azodrine/DDT, contaminated soil, pallets and drums arrived in Great Britain for incineration. By then, Mozambique had already embarked on a national inventory of obsolete pesticides. The survey, which took from August 1994 until March 1995, uncovered 610 different batches of pesticides at 41 sites scattered over the country, with a total volume of 510 tons of pesticides comprising 215 different formulations. Some 175 samples were sent to the GTZ laboratory in Germany for analysis in order to ascertain which of the stocks were obsolete and which could still be used. Just under half (49%) of the samples were found to be unfit for use.

The decisions were based on the 1987 Plant Protection Law, in which the Mozambican government had prohibited the use of 68 different active ingredients. The ban applied to 28% of the obsolete pesticides, most of which consisted of organochlorine compounds, with the remainder comprising mercury compounds. Their application is also prohibited by EU law.

Most of the other 180 tons of pesticides were older than 10 years. Chemicophysical analysis showed that they no longer satisfied the applicable minimum quality requirements. Thus, they could not be recommended for use. To be precise, 34% of the substances were older than ten years, and the age of 41% was no longer ascertainable.

How could this happen? Subsequent inquiries revealed that large amounts of organochlorine compounds were still being imported in the mid-1980s, despite the fact that the industrialized countries already had banned their use during the 1970s. Shortly thereafter, when the Mozambican government prohibited their further application and importation, the pesticides automatically became obsolete.

Apparently, the demand for some of the other agents had been overestimated. The lengthy civil war had done its part by causing a downturn in agricultural production. While 1,536 tons of pesticides were imported in 1987, that volume had dropped to 221 tons by 1989.

Mozambique’s countrywide inventory

Number of sites



Total identified quantity

510 t

Number of active ingredients


Number of identified batches


Obsolete pesticides

249 t

liquid-state formulations

144 t

solid-state formulations

105 t

Still-useful pesticides

261 t

liquid-state formulations

159 t

solid-state formulations

102 t

Contaminated empty containers



The examiners also discovered various inventory control and management deficiencies. Even after years of storage, many of the products could still have been in good condition, had they only been properly kept. However, not even half of the still serviceable pesticides were found to be in irreproachable containers, not to mention the condition of the storage rooms. The labels on half of the products were either missing or had become illegible. After such a long time, it was not possible to determine when the defects occurred and how much of the problem was attributable to the civil war.

The results of the survey not only form the basis of the disposal measures that the competent authorities in Mozambique want to take in cooperation with the Danish International Development Assistance (DANIDA). They also provide valuable information on how to avoid such problems in the future. The Mozambican government apparently had attempted to rectify some of the weak points. For example, with Danish assistance, the government was working to implement the plant protection laws dating from 1987. For several years now, Mozambique also has been practicing PIC procedures and has banned the import of certain pesticides. Thus, another scenario like that involving the chlorinated hydrocarbons should not recur.

Representatives of the Mozambican plant protection service have taken part in GTZ-sponsored qualification training for the storage - and transport-management disciplines. In the future, proper storage procedures should be able to prevent loss of pesticide quality and attendant hazards for people and the environment.

The Mozambican procurement system was modified in 1988/89. Since then, pesticides are being imported only on order and pursuant to competitive bidding. If the system is now able to guarantee demand-appropriate procurement at fair-market prices, the conversion will have been successful.

To be sure, some questions remain: Since 1994 various donors have been investing in agricultural reconstruction programs - the World Bank in cotton production, the African Development Bank in cashew nut production, and the African Development Fund in sugar production. The extent to which pesticides will be supplied within the scope of such programs, and how much consumption monitoring will be engaged in, remain to be seen.

Classy Solutions to Classical Problems

Madagascar: From lorry to ship and back to Europe - return to sender is the most common method of disposal. (1)

Madagascar: From lorry to ship and back to Europe - return to sender is the most common method of disposal. (2)

Madagascar: From lorry to ship and back to Europe - return to sender is the most common method of disposal. (3)

Few waste disposal techniques actually satisfy the goals of - and stringent legal requirements for - the environmentally sound disposal of hazardous waste. Suitable waste disposal facilities are few and far between, particularly in developing countries, many of which have none at all. Among experts, the incineration of pesticides at temperatures above 1,000°C in special high-temperature incinerators is viewed as the presently most economical and environmentally sound form of waste management.

While diverse research institutions in industrialized countries are investigating new methods of disposal, each of them tends to be focused on certain specific problems, usually on a small scale. Such methods are only of conditional value for developing countries, where large quantities of obsolete pesticides and baseline pollution are in need of disposal. Often, the waste in question does not consist of pure substances but of mixtures made up of several substances that are no longer individually identifiable. In almost all cases, there are also contaminated containers, canisters, pallets and soil to be dealt with.

For these reasons, no single technique can be recommended. Each new case requires new reflections and new decisions.

In earlier times, for lack of suitable facilities, proper disposal in developing countries was a rare occurrence. In fact, that is basically the case even now. Frequently, the only solution is to take the pesticides to an OECD country for destruction in a dedicated high-temperature incinerator. Such consignments could well carry the stamp “Return to Sender”, because it was the industrialized world that sent the pesticides to the developing countries in the first place. This is seen as the “classical” or traditional disposal route.

Bad Disposal Options

The following options are unsuitable for the disposal of obsolete pesticides:

- landfilling
- land burial
- deep-well injection
- solar evaporation
- land application

- controlled burning

On the other hand, it also amounts to a risky, expensive business. It involves huge inputs, beginning with the tendering procedure, for there are very few disposal enterprises that are really focused on the special situation of developing countries.

Time and again, the administrative scope is direly underestimated. The Basel Convention and the EU directives pertaining to the transboundary movement of waste have, in principle, created effective instruments with which to prevent “waste tourism”. This, in turn, presents other problems: The original intent was to put a stop to the cheap disposal of hazardous waste from industrialized countries in the Third World. That has met with only partial success. Indeed, these same rules often effectively hamper the reverse route, too: No matter how they originally acquired the hazardous waste, developing countries and those charged with their waste disposal encounter substantial bureaucratic obstacles in trying to get toxic waste out of the country.


Disposal parameters

The cost of toxic waste disposal, and the procedures to be employed, depend on a number of parameters.

Liquid waste is the easiest to handle. It can be delivered to the disposal facility in drums or large tanks. The analysis and interim storage of waste in large tanks are less complicated and, hence, less expensive. In such tanks, the waste can be mixed with other liquids and adjusted to a certain energy level, as required for continuous operation of the combustion plant (incinerator). Moreover, the incineration of liquid waste produces little, if any, residue.

Solid and pasty products, though, require pre-incineration conditioning. Many such products consist of inhomogeneous substances that are difficult to analyze. Solid waste requires homogenization or shredding, plus transfer to a suitable container, prior to its introduction into the combustion chamber. Solid and pasty forms of waste produce more ashes. That, in turn, incurs landfilling fees and, hence, makes the overall disposal operation more expensive.

The combustion gases produced by waste containing substantial amounts of halogens, phosphorus and sulfur require scrubbing to avoid the emission of acetic gases and to preclude formation of dioxins and dioxylfuranes. Such measures are also very expensive and must be accounted for in the final price.

One crucial factor is how the waste is packaged. If it comes in large tanks, a brief analysis will suffice to confirm the tank’s contents. If, however, it arrives in small, unlabeled drums, extensive analysis will be required to avoid unnecessary risks during subsequent treatment of the waste. That, of course, is a considerable expense factor. Drums, too, have to be individually examined and treated as solid waste when they are empty, because the residual deposits are very difficult to remove.

Mauritania: The crushed drums were also sent back for disposal.

Nevertheless, as long as the country in question has no reasonable domestic alternatives, this remains the only possibility. Moreover, the industrialized countries carry a special measure of responsibility in connection with pesticides, for it was they who in one way or another were involved in the supply of most pesticides in the first place. The special incinerators are located there, as are the producers of the subject substances, i.e., the keepers of the product-specific know-how.

For that reason alone, the producers should be involved in disposal planning from the very start. Indeed, the producers’ commitment has waxed significantly in recent years (cf. section 6). If industry were made to systematically share in the expenses of disposal, this would mean a tangible disburdenment of public-sector development assistance. After all, it costs between US $ 2,500 and US $ 4,500 per ton to return pesticide waste to an industrialized country. This covers the cost of everything from stocktaking to the actual incineration.

It would, of course, be disastrous to adopt unsuitable methods in order to save money. Hasty activism can cause serious damage that would cost even more to fix afterwards. Certainly, the problem cannot be solved by simply burying or burning the pesticides.

Nor is there any reason to act prematurely if the potential risks are systematically assessed. Immediate hazards to human health or the environment can be warded off by initial remedial measures, perhaps even the mere refilling of chemicals into new containers. This will always buy enough time for subsequent well-planned forms of disposal.

This could include returning the waste to its country of origin, if that is the only possibility.

Pakistan has accumulated one of the world’s largest stockpiles of obsolete pesticides.


Step by step: From identification to evaluation.

Pakistan: Disposal for Third Parties

Pakistan: A high-risk store is situated right in the middle of Lahore’s Old Town.

Since 1980 huge quantities of pesticides have been accumulating in Pakistan. By now, that Southern Asian country has amassed one of the world’s largest stockpiles of obsolete pesticides. The process of accumulation began when the government halted its prior policy: suddenly, except in Baluchistan, no more free aerial spraying of pesticides was to be provided, i.e., the private sector was, as of immediately, on its own with regard to the distribution of pesticides.

Due to that change in policy, the pesticides in stock in the government-operated stores were no longer given to the farmers free of charge, but instead “stayed put”. With increasing age, they became as unsuitable for sale as for further use. No transition period was provided, during which the existing stocks could have been used up.

According to an inventory based on lists drawn up in 1987, there are an estimated 5,000 tons of pesticides, all told, at the country’s 700 storage sites. These stocks represent a broad range of formulations, mainly insecticides belonging to the organochlorine and organophosphorus group of compounds, in addition to dithiocarbamates. Due to some of the substances’ high acute toxicity and lack of suitable storage conditions, people and the environment in the vicinity of these storage sites are at jeopardy. Consequently, several attempts have been made during the past decade to alleviate the problem.

Following a limited survey, USAID and the government of Pakistan took initial disposal action in 1987. The idea was to incinerate the pesticides at a cement factory in the Punjab. Several pretrial runs were conducted, but disagreements about safety and the environment led to the project’s eventual failure.

In 1993 the government of the Punjab started another attempt to dispose of the obsolete pesticides, this time by simply burying them in the desert somewhere in the southern part of the country. However, public protest forced the government to discontinue the scheme. The pesticides were returned to the more than 100 storage sites whence they came, and where the entire bulk now remains.

Then, in 1996, a new actor appeared on the scene in the form of the Dutch embassy in Islamabad. Having heard about the dilemma, the Dutch launched an initial survey, charging the GTZ Pesticide Disposal Project with its implementation.

In November 1997 a team of experts investigated 15 storage sites in the provinces of Punjab, Sind and Baluchistan. They counted the stored quantities and took samples for analysis at the GTZ laboratory in Germany. They documented the condition of the stores and packages as a basis for risk assessment and, hence, drafted a strategy for disposal of the pesticides.

Most of the store buildings were found to be in dilapidated condition, with broken roofs and unsealed floors. The interiors of the store buildings were found to be in such disarray that it was hardly possible to determine the stored quantities with any degree of accuracy. Nowhere were the pesticides stored in anywhere near the manner deemed necessary for highly toxic chemicals; indeed, they obviously had simply been tossed into the buildings, as indicated by the demolished packages, with leaks having contaminated the ground to an as yet undetermined extent.

The worst and most dangerous of all the storage sites is the one situated right in the middle of Lahore’s very densely populated Old Town. Children in particular are constantly exposed to poisonous vapors and dust from the pesticides. Some of the inspected stores contain large amounts of various agents, including some highly toxic ones, all devoid of safeguards and freely accessible.

Pakistan: Classification of pesticide stocks according to an inventory.

The completed inventory of those 15 stores showed a total of at least 477 tons of obsolete pesticides, only 112 tons of which were still traceable (to 23 different manufacturers). Nearly a third had been produced or formulated in Pakistan. Thus, 16% of the overall quantity correlates to 21 international producers.

A total of 150 samples were taken, representing 336 tons of pesticides. Subsequent analysis revealed the presence of several hundred different formulations in the stores, with more than 45 different active ingredients. Most of the substances are insecticides. In addition to some marginally hazardous products, there are also some highly toxic ones, including a group of pesticides that have since been banned. Many of them are persistent organic compounds, and some of them can be found on the PIC list.

To be sure, as bad as these results of stocktaking appear to be, they can only convey a weak impression of the problem’s full dimension. Note, for example, that the Punjab alone has more than 100 chemical storage sites in addition to the 15 that were surveyed. But then, it is not just the sheer volume that is frightening. The general condition of the storage sites, in combination with an apparently somewhat carefree manner of dealing with such extremely toxic agents, has created a highly risky situation. It is therefore urgently necessary to take immediate measures for reducing the human health hazard.

It would not suffice to merely clear out these stores. Since the other ones may well be in similarly bad condition, the breadth of activity will have to be expanded. Of course, capacity bottlenecks could occur quickly, considering the quantities involved.

How, then, to approach the problem? Naturally, the waste material from the inspected stores in the Punjab could be taken out of the country for disposal according to OECD standards. That, however, would probably be so expensive as to exceed the available financial limits. In addition, this approach would void the chance to help build up the country’s own capacities.

Thus, the best thing to do in any case, even if the most hazardous stores were to be neutralized by exporting their contents, would be to clear out the other ones with the aid of local labor. This would give the Pakistani plant protectors a chance to learn how to handle such waste and, above all, to set up and operate pesticide storage facilities in a future-oriented manner.

Proceeding on this basis, one could even give concrete consideration to the possibility of expanding the surveys and collecting information about possible locations and facilities in Pakistan where disposal could be effected. This would involve genuine development-policy elements: along with the local disposal infrastructure, awareness of the problem would also grow - as would a lot of know-how that would help the local authorities make progress in their work.

Innovative Disposal of Old Contaminations

Tanzania: Incineration in cement kilns is one method of disposal in developing countries.

One basic principle of disposal is that obsolete pesticides must be treated in a manner to minimize the risk for human health and the environment. In developing countries, the traditional solution is to ship the pesticides back to an industrialized country for disposal in a dedicated high-temperature incinerator.

Even proponents of the “Return to Sender” principle do not deny the approach’s obvious drawbacks. Any such transport always involves considerable risk for the environment. Naturally, the cost also increases, since such activities are time-consuming and accordingly expensive. Moreover, the transboundary movement of hazardous waste is rendered particularly toilsome and expensive by international agreements and conventions. Among the governments of developing countries, the return-to-sender philosophy also tends to inspire the belief that the countries themselves are not really at fault.

There are therefore a number of reasons to consider alternative strategies. As such, the search for other options has been a central concern of GTZ’s Pesticide Disposal Project from the very beginning.

In principle, the various techniques for disposing of highly toxic chemicals can be assigned to three different groups: thermal, physicochemical and biological.

Thermal methods

The burning of hazardous waste requires, firstly, high temperatures and, secondly, long holding times.

Incineration also produces new compounds; particularly in the case of incomplete combustion, the reaction products can be even more toxic than the original substances were.

Problem candidates include organochlorine compounds, due to the possible formation of dibenzodiox-ins and dibenzofuranes. Thermal methods are also only conditionally suitable for application to pesticides containing heavy metals or mercury.

· High-temperature incineration

A good incinerator employing multichamber furnaces can destroy 99.9999% of the chemicals at temperatures in excess of 1,200°C, with a sojourn time of several seconds. Such facilities are equipped with efficient stack-gas scrubbing systems and filters with the capacity to hold back such highly toxic compounds as dioxins. However, such facilities are only found in a few western countries, because they are very expensive to build and operate. For example, it costs about US $ 1 per kg to incinerate dieldrin, and that does not include the cost of transportation or packaging.

· Mobile incinerators

Clearly, on-the-spot incineration in the country concerned would be preferable to shipping the waste overseas. Disregarding certain safety issues, it would also be much more economical. Consequently, as an alternative to large, stationary combustion plants, the use of mobile incinerators has become a popular topic of discussion. They, too, are expensive, especially if they are equipped with appropriate means of flue/stack gas cleansing. Moreover, they cannot be used without hesitation for all substance categories. Only a few semi-mobile prototype incinerators have been built to date, and they have not yet found use on a large scale.

Methods of Disposal

Thermal methods

- High-temperature incineration (stationary and mobile equipment)
- Incineration in cement kilns
- Plasmopyrolysis
- Stirred-tank reactor
- Sodium method
- Thermal desorption

Physicochemical methods

- Hydrolysis
- Solidification/stabilization
- Ozonization
- Adsorption onto activated charcoal
- Neutralization

Biological methods

- BioxR-S method
- Shell Bioreg method

(methods for soil cleaning and decontamination)

Mozambique: The quantity and chemistry of the pesticides must be established.

Industry employs, to some extent, so-called Michaelis kilns/furnaces in developing countries, but such furnaces are unsuitable for use in the incineration of plant-protectant formulations. Until now, they have only been used for moderately contaminated packages and, from time to time, contaminated soil.

· Cement factories

The world is dotted with cement factories, including many located in developing countries. Clinker, a cement aggregate, is obtained in large rotary kilns at temperatures up to 1,450°C. Liquid waste can be injected directly into the flame via the oil lance for combustion under optimized conditions - meaning temperatures beyond 1,850°C. The duration of high-temperature exposure exceeds ten seconds. The alkaline environment neutralizes the acidic gases resulting from the combustion process. The ash is integrated into the cement clinker.

For both industry and developing countries, empirical data and the results of systematic analyses are available regarding the incineration of highly toxic waste in cement kilns. This approach offers ideal conditions for the disposal of problem waste and is particularly well-suited for application to liquid waste. The results are comparable to those of a high-temperature incinerating plant, though the necessary conversion work is minor in scale and accordingly inexpensive.

Physicochemical methods

Chemical and physical methods are of limited use for disposing of pesticides. Basically, such techniques and processes are designed to alter the chemical and physical properties of the toxic waste such as to obtain less hazardous or even completely safe products. That, however, entails a quantitative increase as a significant drawback (among others): The descendants, i.e., the reaction products, also require disposal, e.g., by landfilling. Thus, such techniques are only useful for small quantities of toxic chemicals.

· Hydrolysis

Chemically speaking, hydrolysis is the term used to denote the decomposition of organic compounds by interaction with water. If the water is replaced with a strongly alkaline substance - with sodium hydroxide, for example - hydrolysis easily destroys organophosphorus compounds and carbamates. Of course, the reaction products often turn out to be equally hazardous and also have to be properly disposed of. This approach, too, usually involves a volumetric increase and, hence, is more suitable for such small-volume applications as the disposal of cleaning water used for scrubbing the floors and walls of a contaminated store building. Finally, hydrolysis is potentially hazardous and therefore requires experienced personnel.

Mozambique: Containers labeled according to IMDG code.

Mozambique: Packing contaminated soil for transport to the disposal facility.

· Solidification/stabilization

Solidification is an environmentally sound means of binding contaminated solids for subsequent disposal. For example, slightly to moderately polluted soil can be immobilized in this way. The contaminated solids are incorporated into special cements, silicates or polymers in order to bond their highly toxic chemical contents. First, though, it must be assured that the toxicants will not be washed out. Again, the method involves a gain in volume, so while it may be a good choice for the final deposition of pesticide-polluted soil, it is only conditionally suitable for the pesticides themselves.

Biological methods

There are numerous biological methods of decontaminating slightly polluted soil. One approach is to mix pesticide-contaminated soil with specially selected microorganisms and enzymes in a bioreactor. Under ideally controlled conditions, the microorganisms become established in the soil and multiply by feeding on the contaminants, most notably phosphoric esters. To enable specification of suitable working conditions, all such decontamination processes must be preceded by extensive trials designed to isolate precisely the microorganisms that best fit the pollutant in question. Practical tests have shown this technique to be a simple, low-cost method of detoxifying soil - as long as the soil has only been contaminated with either a single pesticide or several pesticides belonging to the same group of active ingredients. If, however, several pesticides with different active ingredients are involved, this form of decontamination is extremely difficult, often even impossible.

The wide-choice predicament

The question of when to use which technique always calls for a case-by-case decision. With but one exception, all disposal projects completed to date have involved returning the waste to the country of origin - according to the return-to-sender principle. The only successful local measure was the one in which GTZ incinerated DNOC at a cement factory in Tanzania.

While all other methods touched upon here are feasible in theory, the concrete-case decision to date has always been to dispose of the waste in a dedicated high-temperature incinerating plant. Indeed, that is still the safest, most cost-effective route to take, even considering the risks involved in shipping the waste back to Europe.

Tanzania: The waste introduction system is a mobile unit developed for the disposal of liquid chemicals. (1)

Tanzania: The waste introduction system is a mobile unit developed for the disposal of liquid chemicals. (2)

The biological, chemical and physical techniques tend not to have what it takes for complete and ultimate disposal. Nonetheless, even in developing countries, they can be useful in preparing baseline pollution for incineration or deposition. The potential advantages would include, for example, reduction of the waste volume and/or of the environmental risk.

Despite the fact that incineration is today’s disposal technique of choice, landfills are still needed. The stack gases pass through several stages of purification in which the pollutants of combustion are filtered out. Also, the process produces slag that has to be disposed of in like manner as the filter dust. At least the volume of the slag and dust is much smaller than that of the original substances.

Monetary appraisal of the options must consider the fact that many pesticides have a high heating value. That, of course, can be beneficial in that it reduces the amount of primary energy required from other sources. This applies to stationary facilities in which, say, electricity can be generated. On the other hand, if disposal is effected via industrial production processes, the problem chemicals can even help reduce expenditures on primary energy for the burners. Pertinent experience with cement factories is well-documented.

The cement industry, however, is not always receptive. Those responsible may fear a loss of image even more than a loss of product quality. In developing countries, too, there is public concern about the incineration of toxic waste, and this is a point that planners should not overlook when weighing their options.

Tanzania: Hot Disposal in a Rotary Kiln

Tanzania: The waste introduction system satisfies highest safety standards.

It took five years, until mid-1996, to dispose of all 57,600 liters of DNOC. As usual, the Pesticide Disposal Project had to do the pioneering work: This was the first time that obsolete pesticides were to be incinerated in a cement factory’s rotary kiln directly in a developing country.

The history of this disposal project goes back to 1991, when the International Red Locust Control Organisation for Central and Southern Africa (IRLCO-CSA) recognized a need for action and turned to GTZ for help. Four decades earlier, IRLCO-CSA had stockpiled large amounts of insecticides in the traditional breeding grounds of the red locust in Tanzania and Zambia in order to be ready “just in case”. The stocks included huge amounts of DNOC.

Due mainly to its persistence, 4,6 dinitro-o-cresol is a highly toxic pollutant. This DNOC was stored too long under poor storage conditions. Eventually, the corroded drums began to leak. The situation became more and more dangerous, particularly at the Muse storage facility, where more than 50,000 liters of DNOC were stored, mostly in leaky drums and large steel tanks situated just a few meters away from the banks of Rukwe Lake. The poison seeped into the soil and, as the groundwater table rose during the rainy season, into the lake as well. The resultant fish kill threatened the local population’s natural resource base.

The Pesticide Disposal Project conducted a survey in 1992. The possibility of local disposal was investigated, and the subsequent plan of action regulated the safeguarding of the stocks and their transfer to Dares-Salaam. It also envisaged the design of a facility in which the DNOC could be incinerated in a cement kiln in line with stringent safety standards. This waste introduction system (WIS) was designed as a mobile unit.


The Waste Introduction System was developed especially for the disposal of liquid chemicals. It is a mobile unit that satisfies highest safety standards.

Since the system operates under high pressure, it is equipped with underpressure and overpressure safety devices and a splash guard for the operator’s workstation. In addition, all essential components are explosion-proof.

After the pesticides were incinerated, the original WIS was left in place for future activities at the cement factory, since the like-method disposal of additional chemical waste and veterinary products had since come under consideration.

Safeguarding measures were commenced with in late 1993. Under adverse logistical and climatic conditions, all 57,600 liters of DNOC stored at the five different sites were filled into containers and transferred by rail to Dar-es-Salaam, where an interim storage facility had been set up on the premises of the Twiga Cement factory in Wazo Hill, where the DNOC was to be incinerated.

That took place in mid-1996 in the largest of the factory’s three rotary kilns. Bayer AG supported the measure by conducting the requisite incineration trials in its own laboratories.

The 4,6 dinitro-o-cresol was diluted in kerosene to a concentration of 20%. The resultant solution was pumped into the supply tank of the WIS and diluted with diesel fuel to a residual concentration of roughly 10%. A diaphragm pump injected the mixture under high pressure directly into the oil lance of the cement kiln. The incineration temperature was situated above 1,850°C. Afterwards, the 450 empty drums were recycled, i.e., cleaned, shredded and melted down at a local steelmaking plant.

In addition to the combustion gases, the process produced a small amount of ash that was subsequently integrated into the hot clinker (nearly 1,450°C) in the cement kiln. (Clinker is an aggregate used in the production of cement.) During the entire program, the cement clinker and dust were sampled but showed no indication of DNOC residue. The emissions were also continuously monitored. No rise in NOx emissions was noted.

Tanzania: For the first time, a large quantity of obsolete pesticides was incinerated directly in a cement kiln.

The actual incinerating process in particular led to some substantial delays, most of which were attributable less to technical difficulties than to administrative and social problems.

Clashes of competence between various authorities caused one delay after another. In addition, the cement factory had not pursued an adequate information policy, so at the beginning of the operation the employees were distrustful of the planned activities. This was the first time that such a large amount of obsolete pesticides was to be incinerated directly in a developing country. There was defensiveness on the part of those who felt like guinea pigs. It took an interdisciplinary team of representatives from various ministries and the university to remedy the situation by backstopping the entire program and monitoring the incineration process. Indeed, that team has since become established as a “fixture” institution in Tanzania that is now supposed to plan and backstop future hazardous waste disposal activities.


4,6 dinitro-o-cresol is a very effective insecticide and herbicide. It is also persistent and, in the dry state, explosive.

Its chemical structure is easier to break down than that of PCB molecules, and there is no danger of polychlorinated diben-zodioxins or furanes forming as a result.

Thus, the stack gas contains only CO, CO2, H2O and NOx, all of which are expelled to the atmosphere. Waste DNOC is regularly incinerated in Germany.

Three Partners - All in One Boat

Mozambique: Industry helps to dispose of toxic waste.

Toxic waste and obsolete pesticides do not just appear overnight. Nor are they the result of any one person’s error or misdeed. Thus, it is only logical for all concerned to cooperate in cleaning up the mess. Successful disposal measures are chiefly characterized by good cooperation between the various actors.

The Pesticide Disposal Project has initiated cooperation with and between a large number of partners, including various governments and nongovernmental organizations, international organizations and the private sector. The span of examples includes cooperation with USAID in the Niger and Morocco, with DANIDA in Mozambique, with Norway’s StrFoundation in Mali, and with the FAO in Ethiopia and Zambia. Shell International Ltd./UK is involved in Madagascar, the Niger and Mauritania, while BASF AG and Bayer AG are active in Mozambique and Pakistan, respectively.

The bottom-line experience has been positive. Since a number of development-cooperation organizations are simultaneously concerned with the pesticides problem, close cooperation is called for as a means of steering the exchange of data and experience. This can help avoid redundancy and, hence, unnecessary expense.

In this connection, GTZ is collaborating with the FAO, which has assumed a coordinating role. With the assistance of GTZ, the FAO’s expert panels have drawn up guidelines for surveys and directives for the disposal of pesticides in large and small quantities. Pesticide Disposal Project staff have represented BMZ at the FAO’s annual government consultations on pesticide disposal and prevention and have taken part in special missions (e.g., Task Force Ethiopia).

An inventory of obsolete pesticides in Africa and the Near East, including the names of products and producers, was published by the FAO in 1996. This caused something of a stir in the pesticides-producing industry, but it also got things going. The Global Crop Protection Federation (GCPF) announced to the FAO that it was prepared to provide both technical and financial assistance to any disposal measures involving products made by its member companies.

This was the result of a long learning process within the industry. As early as the 1970s, the multinational chemical concerns had already been pilloried for their pesticide trade practices with Third World countries. Their pledge to implement the International Code of Conduct on the Distribution and Use of Pesticides is one reaction to that.

The producers are already being held responsible for their products’ past. And in the future, they will have to assume even more responsibility, because more and more people all over the world are becoming aware of such things. Big environmentalist organizations like Greenpeace have also long since gone multinational. Wherever a company decides to do business nowadays, it can expect Greenpeace & Co. to be on the scene. The organization’s international network is very closely knit, and its informal ties with government agencies and supranational organizations are numerous.

Product responsibility accompanies each product through its entire life cycle, from the development, its production and sale to its consumption or disposal. Agenda 21 wants it that way, and the chemical industry has accepted it that way. The key term is Responsible Care, i.e., a global initiative devoted to the promotion of responsible behavior on the part of producers.


Adopted at the 1992 United Nations Conference on Environment and Development in Rio de Janeiro, Agenda 21 serves as a program of action for practically all development-policy fields of environmental relevance. It is, however, not a legally binding instrument. As such, its implementation remains primarily at the discretion of the various governments.

The following chapters pertain to obsolete pesticides:

Chapter 19 deals with the “environmentally sound management of toxic chemicals, including prevention of illegal international traffic in toxic and dangerous products.”

Chapter 20 describes the “environmentally sound management of hazardous wastes, including prevention of illegal international traffic in hazardous wastes.”

Chapter 21 regulates the “environmentally sound management of solid wastes....”

The main points encompass waste avoidance, implementation of the Basel Convention, exchange of information on toxic chemicals and their risks, coordination of international collaboration, upgrading of waste management, and transfer of know-how to developing countries.

This amounts to a public-sector task that calls for regulative international cooperation. In addition, involvement of industry, the research community and nongovernmental organizations is explicitly referred to as desirable and worthy of promotion. Regarding the risks involved, the principle of pollution prevention applies to the entire life cycle of a given chemical. For industry, this equates to responsible care (= product responsibility/liability) and self-initiative in dealing with chemicals.

The Code of Conduct

In 1985 the Food and Agriculture Organization of the United Nations (FAO) adopted the International Code of Conduct on the Distribution and Use of Pesticides. In 1989, the code was amended to include the Prior Informed Consent (PIC) procedure.

This is the first agreement in the world that recognizes the joint responsibility of all social groups involved in any process from the production through the use of pesticides. It addresses chiefly governments, trade & industry, and national and international organizations, including nongovernmental organizations.

The code relates to the:

- testing and licensing of pesticides
- regulative and technical requirements for dealing with pesticides
- distribution and sale of pesticides
- information exchange between importing and exporting countries
- labeling, packaging, storage and disposal of residual pesticides
- availability and use of pesticides
- reduction of health hazards

While the relevant standards are only recommendations, several social groups have pledged to adhere to them voluntarily. Germany’s plant protection law, for example, makes adherence to the Code of Conduct imperative. The Global Crop Protection Federation (GCPF) also demands compliance from its members.

Mozambique: Return to sender - a joint operation together with the pesticide producer.

This initiative endeavors to achieve gradual improvement in matters of health, safety and ecology. Responsible Care therefore accompanies a given product not only through its entire life cycle, but also applies to the internal and external communication of any relevant activities.

This is a point of departure for cooperation in cases where the idea is to help - actively as well as financially - eliminate yesterday’s environmental burdens or to implement strategies that will prevent new burdens before they ever occur. While most companies still showed little interest in such things during the 1980s, most of them are now willing to cooperate.

GTZ has had some favorable experiences in connection with cooperative forms of disposal. Time and again there were large amounts of dieldrin to be disposed of, and Shell International Ltd. was once the sole manufacturer of that pesticide. While the company did discontinue its production and sale during the 1980s, it nevertheless has provided both know-how and funding for projects in the Niger, Madagascar and Mauritania - all in the sense of responsible care.

Such active involvement is rendered all the more interesting by the fact that Shell sold its entire pesticides business in the early 1990s and has not even been a member of the pesticide producers’ association GCPF since that time. As a former producer, however, Shell does still cooperate with GCPF whenever there is a real need for responsible-care action.

Such cases could become increasingly frequent. According to Shell’s own estimates, developing nations still have more than 1,000 tons of dieldrin in store. Shell, however, has undertaken to cooperate with qualified organizations in safely disposing of all remaining stocks of the erstwhile best seller in Third World countries.

GTZ has had positive experiences with other companies, too: in Pakistan, for example, from where there came an inquiry about how to dispose of some 60 tons of gusathion in Peshawar. Pakistani authorities purchased the pesticide about 20 years ago. The first leaky drums were replaced about a decade ago.

While the solution had been transferred from its original drums to new ones, no labels had been added or transferred, so it was no longer possible to clearly identify the manufacturer. Soon after that, the gusathion began to decompose, and the drums came close to bursting. An awful stench emanated from the storage site, wafting over into a densely populated part of Peshawar. The local authorities requested GTZ assistance. Since the Pesticide Disposal Project was able to provide know-how but no funding, it appeared logical to contact the original patent holder.

Bayer AG affirmed its willingness to collaborate with GTZ. Even if it should turn out that the pesticide was not a Bayer product, the company nevertheless wanted to help alleviate the acute hazard. Moreover, GTZ and Bayer had already accumulated some common experience in the form of pretrials for the DNOC disposal scheme. In the meantime, the gusathion has been filled into new shipping containers and will soon be taken to England for disposal.

Seventy-three tons of formulating additives and agro-chemicals from an erstwhile BASF production facility in Mozambique were also successfully disposed of. BASF AG burned the waste at its own cost in a hazardous waste incinerator at the BASF plant in Ludwigshafen.

Thus, coming to terms with the past sometimes even provides impetus for shaping a better future. The money that GTZ saved through the industry’s involvement is working to Pakistan’s benefit, i.e., the funds are being used to pay for preventive measures: pesticide management is being improved, and some weak points of storage and handling eliminated. This amounts to a major contribution toward the future avoidance of new baseline pollution.

Mauritania: Specially trained local personnel pump the contents of the drums into 24,000-liter shipping containers.

Mauritania: Mobile drum press in action.

Mauritania: Responsible Care for the Past

Mauritania: More than 200,000 liters of dieldrin had to be dealt with.

The quantities involved were as huge as the costs incurred, but the project partners, who had worked with each other before, soon had everything under control. GTZ and Shell International Ltd. had already engaged in a number of common-cause activities in connection with dieldrin. Here, in Mauritania, more than 200,000 liters of it had to be dealt with.

To make things worse, the pesticide had been lying around in store for many years in rusty old drums. At one point or another, the product had been redrummed, but the new drums eventually corroded too, and the next transfer was due. In the end, not only the numerous drums of dieldrin, but piles of old pesticide containers had to be disposed of as well.

The organochlorine compound was supplied to the government of Mauritania many years ago, mainly by FAO and other UN organizations. This West African country’s national plant protection service Direction du Dloppement des Ressources Agropastorales (DDRAP), in cooperation with various international organizations, is responsible for the control of locusts. Two-thirds of Mauritania’s land area (south of the Sahara!) is conducive to the spread of locusts. Consequently, storage sites were set up at strategic locations and filled with large quantities of insecticides - just in case.

But some years practically no locusts appeared, and no dieldrin was needed. Eventually, the agent’s toxic properties and high persistence generated public debate, and pressure exerted by environmental associations and development organizations reduced its application to a bare minimum. Finally, Shell stopped producing dieldrin, and the pesticide disappeared from the market.

It did not, however, disappear from the African storage sites. The next time locusts plagued the land, other, less persistent agents were employed, and the old dieldrin remained in store. Mauritania has no means of incinerating or otherwise disposing of such large quantities of pesticides, so the drums just kept rusting away. Eventually, they became so porous with corrosion that dieldrin dribbled out and contaminated the surrounding soil, as attested to by numerous dark stains. Even worse, however, was the fact that it threatened to contaminate the only potable-water well in the entire area.

At the same time, hundreds of empty drums stemming from prior campaigns had been left behind - dirty and unattended - at a collecting point near the harbor of Mauritania’s capital city Nouakchott, with children scampering around between them.

Consequently, in 1995, the government of the Islamic Republic of Mauritania contacted the Federal Republic of Germany and requested assistance for disposing of the dieldrin and the empty containers. BMZ directed GTZ to cooperate with the Mauritanian partner DDRAP, as the owner of the pesticide.

DDRAP provided transport vehicles and personnel for the hardest part of the work. GTZ provided the know-how and the requisite equipment. Shell, as the original producer of the dieldrin, also joined in and cooperated in response to an inquiry by GTZ. With reference to its own product responsibility and to the chemical industry’s Responsible Care idea, Shell offered to:

- assume the entire cost of transportation and incineration and
- assign an in-house expert as resource person.

Mauritania: Redrumming of more than 28,000 l of dieldrin.

First of all, safeguarding measures had to be taken in order to alleviate the acute danger of groundwater contamination around the desert storage site at Ayoun al Atrous. This included the redrumming of more than 28,000 liters of dieldrin, because some of the old drums had already sprung leaks.

That bought enough time to properly address the main problem. However, before any technical solution could be implemented, Mauritania had to sign the Basel Convention. Otherwise, it might have taken years to get the dieldrin shipped back to the Netherlands. And so it only took until the late summer of 1996 for work to begin.

The old dieldrin had to be collected at five different storage sites in various parts of the country. First, the dilapidated drums were packed into overdrums, which are very robust and designed to retain leakage. In time, all the drums were transferred by truck over dirt roads to a guarded storage area near the capital city of Nouakchott. There, specially trained local personnel pumped the contents of the drums into specially designed isotanks (24,000-liter shipping containers). The old drums were cleaned, pressed flat, and loaded onto the ship for transfer to the Netherlands.

A commercial waste-disposal enterprise, the Dutch company AVR Chemie B.V., was entrusted with transferring the waste to the Netherlands and burning all 220 tons (175 tons of dieldrin and more than 44 tons of contaminated drums) in a hazardous waste incinerator.

Of the roughly DM 1 million that had to be spent on the venture, Shell paid upwards of DM 565,000. People who do good usually like to talk about it. That being so, Shell is calling attention to another useful effect of its contribution: Thanks to this noble gesture, the German government saved lots of money that can now be used for funding preventive measures in Mauritania.

Strategies for Tomorrow

Ethiopia: International experts investigated stocks of obsolete pesticides.

Having fulfilled its task of developing concepts for dealing with obsolete pesticides, the GTZ pilot project ended in October 1999 - and all concerned learned a lot.

At first, there were many skeptics in GTZ’s own ranks. Not only did the technical risks act as a deterrent, but many had doubts about the development-policy benefits of such disposal measures, and some objections were lodged against the use of public funds for cleaning up after other people. Now, though, this subject is being dealt with more openly in German technical cooperation, mainly because the project has been successful in finding comrades-in-arms.

By way of cooperative schemes, development cooperation is capable of coping with large stocks of obsolete pesticides.

Experience shows, however, that the search for suitable partners in cooperation is very time-consuming, and that some of the work ends up getting done twice. At today’s pace, it could easily take another 50 years to destroy all the old stocks of obsolete pesticides. Considering the desolate state of most stores, though, there is just not that much time left.

And so it is urgently necessary to better coordinate everyone’s efforts. One promising approach is to set up task forces, i.e., interdisciplinary, international bodies of experts. The FAO, for example, sent such a task force on a successful mission to Ethiopia: experts representing various disciplines explored the situation together and elaborated suggestions on what kind of further action to take.

As far as the highly competitive hazardous waste disposal business is concerned, GTZ pursues no such self-interest goals as the better utilization of existing hazardous waste incineration capacities in industrialized countries. Consequently, the project has continuously endeavored to find ways and means of waste disposal that can be implemented directly in the respective developing country.

Task Force Ethiopia

In late 1998, for the first time, the FAO sent a Task Force, i.e., an interdisciplinary team of experts, to a developing nation. The experts, all stemming from different disciplines and countries, investigated the urgent problem of obsolete pesticides in Ethiopia. All across the country, they found there were at least 1,500 tons of obsolete pesticides in storage at more than 400 facilities. In addition, large quantities of old vessels, pieces of equipment and contaminated soil were discovered.

Doing a good job its first time out, the new Construction Task Force drafted potential solutions and presented them to potential donors at a stake-holder meeting. In addition to practical matters concerning waste disposal, local facilities and the country’s accession to the Basel Convention, the task force’s report places special emphasis on training aspects of the kind called for by Agenda 21 in support of developing countries.

The overall cost of this FAO-implemented disposal activity is estimated at approximately US $ 4.5 million.

A long time ago, it was demonstrated conclusively that pesticides can be incinerated in cement factories in developing countries. But it was not until 1996 that this approach advanced beyond the trial stage. Development of the waste introduction system (WIS) by the GTZ project, coupled with its pragmatic application in Tanzania, showed that the method really does work, even for large-scale activities.

Disposal in the developing country itself is a realistic option, as long as certain technical and political prerequisites are met.

In both Agenda 21 and the Basel Convention, the industrialized nations promised to engage in the transfer of know-how. As of this writing, the proven methods apply only to the incineration of nonhalogenated pesticides in cement kilns. By modifying such facilities, for example through the addition of a WIS in Tanzania, cement kilns can be rendered suitable for use in burning other forms of hazardous waste, as well. In view of the precarious waste-disposal situation in developing countries, this certainly amounts to a tempting option. From a political standpoint, though, it only makes sense as long as accompanying control mechanisms effectively preclude misappropriation of the incinerating facilities by unscrupulous profiteers.

Technology centers

Population growth and industrial expansion are forcing developing countries to adopt suitable ways and means of waste disposal and avoidance. In each country, all requisite activities should be compiled in a waste management plan, and a disposal and information center should be established for the purposes of hazardous waste disposal and prevention. Appropriate recycling methods can be a major factor in the preservation of local resources and should therefore be promoted.

The purpose of technology centers would be to establish domestic capacities for safeguarding, recovering and disposing of highly toxic waste, as well as to disseminate information and provide training. Structures for exporting waste (Return to Sender) need to be created, and cement factories converted for disposing of obsolete pesticides and other toxic chemicals. A collecting and recycling system for other substances would also need to be established. Small and medium-sized companies could look for assistance here for optimizing their production techniques and introducing new technologies with less waste incidence.

An environmental information and monitoring system integrated into the technology center would serve legislative purposes as well as economic promotion and training. It would serve the authorities as a working platform and could provide a basis for human resource training in such areas as the handling and storage of problem substances. The disposal and information center would be the nucleus of a waste management program, with all activities being implemented, monitored and managed by the center. Such technology centers can provide connecting links between North and South, thus promoting the transfer of know-how from industrialized to developing countries, as called for in Agenda 21.

Active promotion of technology centers in developing countries could help further the development of disposal techniques on a local basis. It would also make a good platform for propagating avoidance strategies, for, from a development-policy standpoint, disposal measures are only justifiable as one-shot schemes.

Post-disposal mechanisms designed to eliminate the causes of pesticide accumulation must come to bear.

The FAO’s Provisional Guidelines for the Prevention of Accumulation of Obsolete Pesticide Stocks, dating from 1995, provide an excellent guide. Concrete approaches for governments and development cooperation organizations, as well as for development banks, industry and users, were illuminated at the 3rd Intersessional Group Meeting at the Intergovernmental Forum on Chemical Safety (IFCS).

Unfortunately, disposal activities are still not being systematically tied in with prevention programs. All concerned should be seriously interested in not finding themselves in the same situation again a few years later. Thus, the planning of disposal measures should include the binding specification of preventive measures.

One goal of development cooperation is to help the partner countries introduce and monitor prevention programs. The creation of a legal framework and the voluntary conclusion of pertinent agreements are both equally conceivable. Likewise, organizational and technical infrastructure is required for monitoring and enforcing adherence to the respective rules and regulations.

In many developing countries, such prerequisites are just beginning to emerge. Often, there are not even any laboratories with the equipment needed for determining the quality of a formulation and comparing it with the given specifications. Equally often, the existing pesticide storage facilities lack the requisite minimum safety standards, and store management procedures are very inadequate and fragmentary. Many laws regulating the treatment of agrochemicals are still being written.

Madagascar, however, stands as an example of how much progress can be made with modest means. It is easy to see that Madagascar seriously intends not to repeat past mistakes.

Training Course: Dry Runs at a Chemicals Store

Training Course in Germany: Focus on the management of pesticide stores.

As many disposal schemes have shown, a large percentage of obsolete pesticides only became obsolete because the basic principles of proper inventory control were not adhered to. Naturally, the management of the store and any transportation involved must be legally regulated. But then one cannot always wait that long. Those responsible for agrochemicals in developing countries therefore welcomed the practical assistance which GTZ offered in 1995 in the form of a training course on “Management of Pesticides Storage and Transportation”.

A discussion among participants from seven developing nations of Africa and Asia identified the problem: Local infrastructure is usually very poor, and there is little awareness of how much damage can result from a lack of good store management.

The course’s main aim was to heighten the attendees’ awareness of both the hazards and the economic damage that can be done to people and the environment by inadequate inventory control and handling procedures. The participants learned modern methods of stockkeeping and safe handling of toxic chemicals. By way of practical exercises, it was successfully demonstrated that these techniques can be introduced in developing countries without major financial expenditures.

The School of Agriculture, Food and Environment (DEULA-Rheinland) conducted the training on GTZ’s behalf. Also participating were Germany’s three largest producers of pesticides, various carriers, and fire-prevention experts. The course was rounded off with a seminar on crisis intervention.

Cooperation is the key - with the mass media, for example, in order to get attention; and trade associations, international organizations and action groups are important, too. It is also important to cooperate with producers and government agencies. All this serves to generate sustainable networks. At the end of the course, the participants were ready to go home and serve as multipliers with the knowledge it takes to get such networks established.

Prevention of Obsolete Pesticides - A Proposal from Madagascar

Pesticides become obsolete for the following reasons:

· Overestimation of demand and requirements:

Locust invasions fail to materialize; the local population refuses to use DDT as a prophylaxis against malaria; remote villages cannot be reached for lack of vehicles; government-operated agricultural production facilities are shut down

· Administrative problems concerning the distribution of donor supplies

· Insufficient storage capacities:

Poor construction; destruction of storehouses by cyclones

· Poor store management:

In nearly half of more than 150 storehouses, the pesticides were found to have been placed on the floor instead of on pallets, and 80% of all stores had no stock lists

· Poor product quality:

Either the pesticides themselves or their containers are of inferior quality and, hence, unmarketable

· Loss of effectiveness due to a gradual buildup of insecticide resistance on the part of pests

Introduced and planned remedial measures

Donor terms of reference

Recipient terms of reference

- Pesticides should only be supplied as an ultima ratio in the sense of integrated plant protection

- Pesticides should only be supplied as an ultima ratio in the sense of integrated plant protection

- No pesticides should be supplied unless accompanied by application monitoring

- The desired agents and containers should be adequately specified

- Partial deliveries allow better adjustment to storage capacities and infestation situations

- Supply contracts should include redemption clauses for products that are either unneeded or have been found to be of unsatisfactory quality

- Unwanted or unneeded pesticides can be returned to the producer or vendor

- Importing checks/inspections, in particular quality-assurance inspections at the donor’s expense

- Empty drums and containers can be returned to the producer or vendor

- Legal regulations governing the construction and operation of pesticide stores

- Introduction of consumption records and disposition monitoring

- Improved store management; issue of storehouse operating licenses that can be revoked in case of poor management

- Conduct of systematic checks and inspections at all stages of the pesticide’s life cycle


Groupe de travail sur les pesticides pmadagascar: Canevas pour l’blissement d’une charte pour rire les risques d’accumulation excessive de lots de pesticides nonsouhait(1999)

Reference Projects 1991 - 1999, last update: October 1999






June 99

Type of intervention


(Province of Punjab)

Various pesticides

300 t


Analytical survey, safeguarding and disposal operation; on behalf of The Royal Netherlands Embassy


Democratic Republic of Congo

Fenitrothion and other pesticides

360 t


Analytical survey, safeguarding and disposal operation, prevention scheme



Various pesticides and agrochemicals from a former pesticide formulation plant

73 t


Disposal operation
Bilateral project; in cooperation with BASF AG and Werkhof Darmstadte. V.



Various pesticides

Approx. 1500 t


Participation in a task force of the FAO
Survey, risk assessment and working out an appraisal of options for disposal; on behalf of the FAO



Various pesticides

80 t


Disposal measure and prevention scheme; in cooperation with DPV, SDC, GCPF



Various pesticides

470 t


Analytical survey and risk assessment; on behalf of The Royal Netherlands Embassy



Gusathion Dimethoate and contaminated soil

60 t*
50 t


Safeguarding and disposal measure*
Bilateral project in cooperation with Bayer AG



Various pesticides

337 t


Disposal operation; in cooperation with FAO.



contaminated pesticide containers (drums)

175 t
45 t


Disposal operation; in cooperation with Shell International Ltd./UK




57 t


Analytical survey, risk assessment and disposal of 57 tons in a cement kiln/Dar-es- Salaam; in cooperation with IRLCO-CSA




Assistance with construction of a pesticide store



Various pesticides

70 t


Survey and risk assessment; on behalf of StrFoundation (Norway)



Various pesticides


Safeguarding measures and backstopping of the disposal operation




208 t


Analytical survey and risk assessment, appraisal (options for disposal), supervision of the disposal operation. Project in cooperation with AVCASA/RSA and the Namibian government




International seminar in transportation and storage management of pesticides




30 t


Survey, risk assessment and safeguarding



Strategy for an inventory of obsolete pesticide stocks in southern Brazil



Various pesticides

510 t


Countrywide survey. Bilateral project; in cooperation with DANIDA



Various products, ex German Democratic Republic

460 t, 50% obsolete products


Inventory and evaluation of options for disposal.
Mission of a joint expert group from different German ministries and GTZ



Monochrotophos/DDT and associated waste

80 t
80 t


Disposal operation
Bilateral project




47 t


Disposal operation; in cooperation with Shell International Ltd./UK



Contaminated soil

16 m³
(40 t)


Appraisal (options for disposal methods)



Methyl bromide

40 t


Appraisal (options for disposal)




1,800 t


Analytical survey and risk assessment Appraisal of options for disposal; in cooperation with USAID




60 t


Disposal operation; in cooperation with USAID and Shell International Ltd./UK


Bolwerk, R. (1992): Feasibility study for the disposal of DNOC at the TWIGA cement works in Tanzania; GTZ

Bolwerk, R. (1991): Feasibility study for the pesticide disposal at the ASMARA cement works in Morocco; GTZ

FAO (1999): Inventory of Obsolete, Unwanted and/or Banned Pesticides Stocks in Africa and the Near East; Food and Agriculture Organization of the United Nations, Rome; Inv-5-99: GCP/INT/650/NET

FAO - Pesticide Disposal Series 6 (1998): Prevention and Disposal of Obsolete and Unwanted Pesticide Stocks in Africa and Near East; Third Edition; Food and Agriculture Organization of the United Nations, Rome; Field document GCP/INT/650/NET

FAO - Pesticide Disposal Series 4 (1996): Disposal of Bulk Quantities of Obsolete Pesticides in Developing Countries; Food and Agriculture Organization of the United Nations, Rome; Field document GCP/INT/572/NET

FAO - Pesticide Disposal Series 3 (1996): Pesticide Storage and Stock Manual; Food and Agriculture Organization of the United Nations, Rome; Field document GCP/INT/572/NET

FAO - Pesticide Disposal Series 2 (1995): Prevention of Accumulation of Obsolete Pesticide Stocks; Food and Agriculture Organization of the United Nations, Rome; Field document GCP/INT/572/NET

Farmers Chemical Handbook 96; Meister Publication Company, Ohio, USA

GCPF (3/1999): “Obsolete Stocks of Crop Protection Products. GCPF Position”.

GCPF (12/1999): “GCPF and Obsolete Stocks - An Update”. Paper presented at the Fifth Conference of The Parties to the Basel Convention, December 6-12, 1999, Basel, Switzerland

GTZ & Shell (1993): Pesticide Disposal Madagascar, Video, 23 min.

Guenther, D., Schimpf, W. A., Vaagt, G. (1998): “Disposal of Obsolete Pesticides - joint solution for”; Pesticide Outlook, December 1998

Harnisch, K. (1991): onomie der Entsorgung chemischer Pflanzenschutzmittel; GTZ

Huden, G. H. (1990): Pesticide Disposal in a Cement Kiln in Pakistan: Report of a Pilot Project and Test Results from a Pilot Burn of Overaged Pesticides, D. G. Khan, Punjab, Pakistan; Agency for International Development, AID/OFDA; Washington, D.C.; USA, 1990

IPCS International Programme on Chemical Safety: The WHO-Recommended Classification of Pesticides by Hazard and Guidelines to Classification 1994 - 1995; WHO/PCS/94.2; Geneva/Switzerland

Jensen, J. K. (1997): “Pesticide Disposal in Developing Countries”. An international train-the-trainer course developed by the US Environmental Protection Agency, Office of Pesticide Programs.

Schimpf, W. A. (1988): Destruction of Pesticides and Chemical Waste by Means of a Cement Kiln. Pesticide Management and Integrated Pest Management in Southeast Asia (edited by P. S. Teng and K. L. Heong), College Park; Maryland, USA, Consortium for International Crop Protection, pp. 423 - 433

Schimpf, W. A. (1990): Disposal of Pesticides and Chemical Waste in a Cement Kiln in Malaysia, Pesticide Disposal Conference; Niamey, Niger

Schimpf, W. A. (1993): Dieldrin-Entsorgung Madagaskar, Abschlussbericht, GTZ

Schimpf, W. A. (1994): Pesticide Disposal Management - Experience gained by the Pesticide Disposal Project of the GTZ, International Pest Management Congress, Symposium on Pesticide Disposal: Prevention and Management Strategy; San JosCosta Rica, 18 - 22 July

Schimpf, W. A. (1995): Lagerung von Pflanzenschutzmittel-Hilfsstoffen und Pflanzenschutzmitteln in der ehemaligen BASF-Formulierungsanlage in Chimoio/Mosambik - Situationsbericht; GTZ

Schimpf, W. A. (1995): Appraisal of the Situation of the Obsolete Pesticides in Keetmanshoop/Namibia and Approval of the Different Options of the Environmentally Sound Methods of Disposal; Final Report; GTZ

Schimpf, W. A.: (1995): L’mination des vieux pesticides et la dllution des sites contamina lumi de “l’mination de la dieldrine adagascar”, Symposium sur la lutte antiacridienne adagascar, Tul, Madagascar

Schimpf, W. A. (1997): Entsorgung von Pflanzenschutzmittel-Altlasten in einem Entwicklungsland: Erfahrungen mit der Verbrennung von Dinitro-o-Cresol in einer Zementfabrik in Tansania. Presentation in the Haus der Technik e. V.; Essen, Germany

Schimpf, W. A. (1998): Dieldrin Disposal Mauritania - Measure to secure and dispose of 220 tonnes Dieldrin and old pesticide containers in Mauritania (1994 - 1998); Final Report; GTZ

Schimpf, W. A. (1998): Disposal of Obsolete Pesticides in a Cement Kiln in Tanzania. 5th International HCH and Pesticides Forum; Leioa/Spain, 25 - 27 June

Schimpf, W. A. (1998): Physical Survey in Pakistan - Site Visit Report and Proposal for the Removal of Obsolete Pesticide Stocks in the Provinces of Punjab, Sind and Baluchistan; Final Report for the Royal Netherlands Embassy; Islamabad, Pakistan

Schimpf, W. A., Guenther, D. (1997): Enqu sur les pesticides obsols et les sites contaminpar les pesticides dans la Rblique Islamique du Mali. Rapport, GTZ and StrFoundation

Schimpf, W. A., Pancas, M. (1995): First nationwide survey to document old problem stocks of plant protection products in Mozambique. Unpublished, GTZ

Strotmann, C. (1999): Evaluierung des Projektes Entsorgung von Pflanzenschutzmitteln in Entwicklungslern, PN 90.2152.8-01.100, ARCADIS Grebner Umwelt GmbH, Mainz; GTZ

The Pesticide Manual: 10th Edition, Editor Clive Tomlin; Crop Protection Publication, Farnham, Surrey GU9 7PH, UK

The Pesticide Manual: 11th Edition; Crop Protection Publication; British Crop Protection Council; Surrey, UK

The Pesticides Trust (1999): “Pesticides Trust Activities in the area of prevention, management and disposal of obsolete pesticides”. In: Pesticides News N° 44, June 1999.



A substance or preparation that kills mites.

Active agent

The active component of a chemical plant protection product/pesticide (® formulation).

Cement clinker

The glassy, clinkerlike product of fusing together clay and limestone as the first stage in the manufacture of cement. The cement clinker from the rotary kiln is finely comminuted in roller or tube mills containing steel balls. This yields the extremely reactive product called cement. To obtain Portland cement, about 5 wt. % gypsum is added to the cement clinker. The essential starting materials for use in the production of cement are lime (chiefly calcium carbonate) and clay minerals (mainly alumosilicates), which must be mixed in the proper proportions. Depending on the type of cement to be produced, small amounts of magnesium carbonate, iron oxide and/or quartz are added. The ground stock is filled into the rotary kiln as raw powder and burnt to obtain cement clinker.


Corruption of a substance or material with undesirable impurities/admixtures.


Preparation of an ® active agent, usually in the solid or liquid state, together with correctives, according to a formula to obtain a commercial-grade plant protection product/pesticide.


A substance or preparation used to destroy or inhibit plant growth (weedkiller).

High-temperature incinerating plant

High-temperature incinerators are a special combustion plant used for the environmentally sound destruction of hazardous waste. The temperatures of incineration prevailing in the rotary kiln and the downstream combustion chambers are selected to destroy the toxic contents of the waste material. This requires temperatures of 1,200°C and higher, an ample supply of oxygen via secondary air, and gas retention times in excess of 2 seconds in the combustion chamber. The stack gases resulting from the combustion process are passed through electrostatic dust control filters, and the gaseous pollutants are removed by stack-gas scrubbers. Additional steps are included to effect removal of organic residues, dioxins and furanes. The incineration of hazardous waste is subject to very strict (national and European) statutory limits.


A substance or preparation used for the control of insects.

Integrated plant protection

A combination of processes and procedures designed to minimize the need for chemical pesticides by prioritization of biological, biotechnical, plant-breeding and crop/soil cultivation techniques.


Chemical compounds that differ in their physical or chemical properties despite their mutually identical molecular compositions and relative molecular masses.


Term used to express the stability of organisms and substances over time in a given medium.


Chemical and biological substances employed in averting biotic and abiotic detriment to plants.

Pesticide resistance

Hereditary resistance to pesticides on the part of certain subspecies, types or strains of causative organisms (pests).

Rotary kiln

Also referred to as “revolvers”, rotary kilns consist of nearly horizontal metal tubes measuring several meters in diameter and between 10 and 200 meters in length. They are lined with refractory bricks. A rotary kiln rotates slowly around its own longitudinal axis such that the top-loaded material slowly wanders toward the opposite - hot - end, which is heated by a flame that feeds on a lance-injected mixture of oil and air or coal dust and air. The hottest zone is near the flame, of course. In this area, called the sintering zone, the kiln run heats up to beyond 1,450°C, consequently undergoing chemical transformation. Rotary kilns serve in the manufacture of cement clinker and in high-temperature incinerating plants used for destruction of hazardous waste.


The degree to which a substance is poisonous



Crop Protection and Animal Health Association (South Africa)


German Federal Ministry for Economic Cooperation and Development


Danish International Development Assistance


Direction du Dloppement des Ressources Agropastorales (Directorate of Agro-Pastoral Resource Development)


Directorate of Plant Protection


Environmental Council of Zambia


European Union


Food and Agriculture Organization of the UN


Federal Republic of Germany


Global Crop Protection Federation


German Democratic Republic


Deutsche Gesellschaft fhnische Zusammenarbeit (GTZ) GmbH (German Technical Cooperation)


Intergovernmental Forum on Chemical Safety


International Maritime Dangerous Goods


International Red Locust Control Organisation for Central and Southern Africa


Nongovernmental Organization


Organisation for Economic Co-operation and Development


Republic of South Africa


Swiss Development Cooperation


United Nations Development Programme


United States Agency for International Development


World Health Organization


Waste Introduction System

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