Selection and Procurement of Pesticides

Pesticides can harm people, animals and the environment. It is therefore important to pay adequate attention to selection and procurement procedures. This section provides further technical background regarding the selection and procurement of pesticides.

Procurement of the wrong type or quantity of products may result in:

• acute poisoning of users;
• chronic poisoning of people, leading to cancers, birth defects and chronic health problems;
• disruption or destruction of ecosystems;
• leftover pesticides becoming unusable/obsolete and turning into hazardous waste.

1. Determining the WHO Hazard Class for specific pesticides
2. Identifying controversial products
3. POP and PIC lists
4. Procurement
5. Preventing products becoming hazardous waste
6. Points for special attention

Determining the WHO Hazard Class for specific pesticides

The World Health Organization (WHO) provides an internationally accepted standard for hazard classification in The WHO Recommended Classification of Pesticides by Hazard and Guidelines to Classification. This document is updated every two years.

The WHO classification distinguishes 4 different hazard classes (see below). The appearance of a given active ingredient in WHO Class IA, IB or II should trigger closer evaluation. However, the relevant factor is the classification of the formulated product and not the active ingredient (A product with a high concentration of a Class II active ingredient can be more hazardous than a product with a very low concentration of a Class I active ingredient).

The classification by hazard is based on the acute toxicity expressed in LD50 values. LD50 stands for Lethal Dose 50% and is a statistical estimate of the dose, in milligrams of the material per kilogram of body weight, which will kill 50 percent of a group of test organisms. The lower the LD50, the more toxic the product. Both oral and dermal LD50s are used, since many pesticides are easily absorbed through the skin. Toxicity through inhalation can also be a hazard, but the measurement and evaluation of this hazard is more complex.

Often the manufacturer declares the Hazard Class on the label or in other documentation regarding the product concerned. If the Hazard Class is not declared it can be estimated as follows:

1. Look up the LD50 for the active ingredient (a.i.) in the WHO Tables (see Tables 1-4) and determine whether it concerns oral or dermal toxicity. (The default is oral toxicity. If it concerns dermal toxicity instead of oral toxicity, the figure in the LD50 table will be preceded by the letter D.)
2. Calculate the estimated actual LD 50 of the formulated product by using the formula:

Use the table below to determine the Hazard Class on the basis of the calculated LD 50, the physical state of the formulated product (liquid or solid) and the most hazardous mode of action oral or dermal). The physical state of a product can generally be determined by the unit of quantity (L or Kg) or the formulation code (detailed below table).

Some common codes for formulations that are often part of the product name and provide indication of its intended mode of application and physical state:

 

For further information, see also:

Pesticide formulations and application techniques 
Reducing health and environmental risks 
Newer products with higher selectivity and lower toxicity

Identifying controversial products

In addition to products with a high acute toxicity, products may be considered controversial or undesirable because of their chronic toxicity or impact on the ecosystem or the environment.

Indicators that there may be something wrong with a product include:

• Inclusion on the list of Persistent Organic Pollutants (POPs list- see below)
• Inclusion on the list of products subject to the Prior Informed Consent procedure (PIC list -see below)
• Registration of the proposed use of the product has been rejected or cancelled for health or environmental reasons in the US and the EU

POP and PIC lists

Requests for Bank-financing of products that appear on the POPs and PIC list (see box below) should be given extra scrutiny. In most cases these product will be excluded from Bank-financing on the ground that these provide unnecessary risks to the environment or human health (OP 4.09 Paragraph 6a and 6c). A possible exception is the use of DDT for malaria control.

In 1985, the Pesticide Action Network established a "dirty dozen" list of pesticides that are highly hazardous and a common cause of farmer poisoning, or a threat to the environment because of their persistence. This Pesticide Action Network is a global network of NGOs that campaigned for the phasing out of these products. At that time, many aid agencies did not yet have a policy on pest management and the "dirty dozen list" became a tool for aid agencies, which adopted it as a black list of pesticides excluded from procurement. Since 1985 the list has been updated several times and now contains 20 products. In the late 80s and early 90s the Bank also used this list as a black list. The Bank now uses the criteria in OP 4.09 for the selection of pesticides. The products on the "Dirty Dozen List" are excluded from Bank financing because they do not meet the selection criteria of OP 4.09. The only exception is the use of DDT for Malaria control (see section on POPs Convention).

Pesticide	"Dirty Dozen" (1985 + updates)	Appears on PIC list (2010)	Appears on POP list (2010)
2,4,5,-T	Xx	X
Aldicarb	.Xx	.
Aldrin	X	X	X
Binapacryl	.	X	.
Captafol	.	X	.
Chlordane	X	X	X
Chlordecone		X	X
Chlordimeform	X.	X
Chlorobenzilate	.	X	.
DDT	X	X	X
Dieldrin	X	X	X
Dinoseb and dinoseb salts	.X	X
1,2-dibromoethane (EDB)	.X	X
Endrin	X	.	X
Fluoracetamide	.	X	.
HCH (mixed isomers)	X.	X
Heptachlor	X	X	X
Hexachlorobenzene	X	X	.
Lindane	X.	X
Mercury compounds	.	X	.
Mirex	X	.	.
Paraquat	X.	.
Pentachlorophenol	X.	X
Toxaphene	X	X	X
Monocrotophos*	.	Certain formulations	.
Methamidophos*	.	Certain formulations	.
Phosphamidon*	.	Certain formulations	.
Methyl-parathion*	X.	Certain formulations
Parathion*	X.	X
Alpha hexachlorocyclohexane		X	X
Beta hexachlorocyclohexane		X	X
Pentachlorobenzene		X	X

FAO Guidelines for the Prevention of Accumulation of Obsolete Pesticide Stocks recommend that for centrally organized pest control programs, such as vector control, and locust and other migratory pest control programs, quantities of pesticides supplied should not exceed a one year requirement. Nor should these exceed the capacity to store, transport or apply the product concerned. The storage capacity is determined by the availability of storage space in adequate pesticides stores. The application capacity is determined by the available application equipment, the availability of staff to use the equipment and the transport facilities to bring staff and products to the location where application is needed. Exceeding any of these capacities is likely to lead to obsolete pesticide stocks.

Points for special attention

• Donor coordination: In some cases, inadequate donor coordination led to excessive supplies of pesticides under declared emergency situations. Such excessive stocks are likely to contribute to the build up of stockpiles of obsolete pesticides.
• Consider supply in small consignments spread over time to reduce the risk of build up of stocks. New consignments should only be released upon confirmation that earlier consignments are being depleted at the anticipated rate.
• Changes of products or formulations may require further training of users.