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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 documentHow to Gain Insight
View the documentAlbania: Sidetracked Pesticides
View the documentMozambique: A Civil-War Legacy

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).