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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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View the documentFrom Hazardous Waste to Problem Solver
View the documentZambia: Cleaning up a Country

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