Background to the development of FAO and WHO specifications for pesticides

FAO specifications

Acting on the recommendations of the FAO Conference on Pesticides in Agriculture^[2], which were endorsed at the second session of the FAO Committee of Experts on Pesticides in Agriculture^[3], the Director-General of FAO established an FAO Working Party on the Official Control of Pesticides on 25 July 1963 under the provisions of the statutes of the FAO Committee of Experts on Pesticides in Agriculture.

The purpose and terms of reference of the Working Party were to advise and assist the Director-General on all matters related to the official control of pesticides, and to prepare a model licensing and approval scheme; to provide guidance on efficacy and safety in use and transport; and to produce specifications for pesticides used in agriculture analogous to those prepared by the World Health Organization (WHO) for public health purposes.

The Working Party was subsequently divided into two sections: Section A, to prepare a model scheme for the official control of pesticides and to provide guidance on labelling; and Section B, to prepare specifications for pesticides used in plant protection.

In 1975, The Working Party was renamed the FAO Panel of Experts on Pesticide Specifications, Registration Requirements and Application Standards^[4]. Its purpose and terms of reference were to advise the Director-General on the official control of pesticides, efficient and safe application methodology and biological testing standards, with particular reference to developing and adopting specifications for agricultural pesticides. Section B of the Working Party became the Group on Specifications. In 1989, the Panel of Experts on Prior Informed Consent was amalgamated with the other Groups, to become part of the Panel of Experts on Pesticide Specifications, Registration Requirements, Application Standards and Prior Informed Consent. The Group on Specifications held formal meetings in 1977, 1979, 1981, 1992, 1997 and 1998 and, for many years, has held additional (informal) technical meetings in association with the annual meetings of the Collaborative International Pesticides Analytical Council (CIPAC).

The first edition of the FAO Specifications Manual was published in 1971 as FAO Agricultural Development Paper No. 93. The second, third and fourth editions were published in 1979, 1987 and 1995, as FAO Plant Production and Protection Papers No. 13, No. 85 and No. 128, respectively.

In 1996, a draft plan was prepared by the FAO Group on Specifications, to change the procedures by which specifications were developed and applied. The objectives were (i) to prepare specifications by a formal evaluation procedure that is transparent and analogous to that employed by the FAO/WHO Joint Meeting on Pesticide Residues (JMPR); (ii) to enable JMPR evaluations of pesticide toxicology and residues to be linked to the evaluations of the technical active ingredients; and (iii) to limit the scope of specifications to manufacturers whose technical active ingredients have been evaluated by the Group. Following extensive consultation and comments from interested parties, the procedures were adopted by the FAO Group at formal meetings in October 1998, held in Rome. The new procedures were presented in the fifth edition of the Manual (FAO Plant Production and Protection Paper No. 149, 1999). In addition, the Manual was extensively reorganized. Statements of the aim, applicability, methods and requirements were provided for all specification clauses, which were grouped according to broad characteristics. Similarly, for clarity and ease of comparison, the specification guidelines were grouped according to the general features of the products involved. A Spanish edition of the 5^th edition of the Manual was made available in 2001.

Specifications developed under the two procedures are superficially similar in appearance but have a very different basis. Specifications developed under the old procedure could be applied to any manufacturer’s product. Specifications developed under the new procedure apply only to the products of manufacturers whose data have been evaluated by the Group on Specifications. Prior to 1999, all specifications were produced in hard copy only. Under the new procedure, specifications are published on the internet and only available in hard copy form on request. Specifications published on the internet are integral with the corresponding evaluations of data, so that users of the specifications can be informed of the data and scientific reasoning which support the specification.

WHO specifications

The WHO Pesticide Evaluation Scheme (WHOPES) was set up in 1960 and remains the only international programme that promotes and co-ordinates the testing and evaluation of pesticides intended for public health uses. The International Code of Conduct on the Distribution and Use of Pesticides^[5] constitutes the framework for WHOPES in promoting the safe handling and use, efficacy, cost-effective application and quality control of pesticide products/formulations for public health use. The development of specifications for pesticides and application equipment, for use in international trade and quality control, forms an integral part of the WHOPES programme.

WHOPES functions in close collaboration with national disease and pest control programmes and national pesticide registration authorities, many international and regional organizations and institutions concerned with pesticide management, legislation and regulation, research institutions and with industry.

WHOPES recommendations take account of existing published and unpublished data and are based on consideration of different factors which may influence performance of products for a given application. The recommendations are for global use, but small-scale local testing of the product is necessary to determine performance under specific local conditions and target species.

The global objectives of WHOPES are to:

- facilitate the search for alternative pesticides and application methodologies that are safe and cost-effective; and

- develop and promote policies, strategies and guidelines for the selective and judicious application of pesticides for public health use, and assist and monitor their implementation by Member States.

In its present form, established in 1982, WHOPES comprises a four-phase evaluation and testing programme.

Phase 1. Technical or formulated pesticides are tested for efficacy and persistence using laboratory-bred arthropods. This phase also incorporates and study of cross-resistance with the various classes of pesticides currently available and the establishment of tentative diagnostic concentrations for the detection of vector resistance in the field. Compounds are also evaluated, in close collaboration with the WHO Programme on Chemical Safety (WHO/PCS), for their safety for humans and the environment. Minimum laboratory experimentation to allow the confirmation of the basic toxicological and ecotoxicological information available from the manufacturer or other sources, in the light of the particular requirements of WHO, may also be carried out by appropriate WHO collaborating centres.

Phase 2. This phase comprises studies on natural vector populations in the field, on a small scale and under well-controlled conditions, to determine application doses and assess the efficacy and persistence of the pesticide. Where appropriate, the action of products on non-target fauna is verified. Phase 2 is also the first opportunity to document any harmful effects of the product upon operators in a field situation.

Phase 3. WHO, industry and one or more institutions located in disease endemic countries undertake to assess the efficacy of the product on a medium or large scale against a specified disease vector. Phase 3 comprises entomological, safety and, where appropriate, epidemiological evaluation. The institution supplies qualified staff for implementation, while the manufacturer supplies the insecticide and the funds needed for the trial. WHO bears the technical responsibility for the operation and is involved in the field through independent consultants. All three parties participate in drafting the trial protocol in accordance with a pre-established model that needs to be adapted to each situation. The final report is drafted by the institution, which submits it to WHO for evaluation. The report is then submitted to the manufacturer for review.

A scientific committee, the WHOPES Working Group, assists WHOPES in reviewing evaluation reports and assessing current knowledge about products and their intended applications, and makes recommendations to WHOPES on their public health use. The reports of the WHOPES Working Group are issued as WHO documents and are widely distributed^[6].

Phase 4. This phase is concerned with the establishment of specifications^[7] for the technical product and the formulations evaluated. Prior to 2002, draft specifications proposed by industry were reviewed by the WHO Expert Advisory Panel on Vector Biology and Control and WHO collaborating centres and were then issued as interim specifications. These were then reviewed every five to six years by the WHO Expert Committee on Vector Biology and Control, which could recommend their publication as full WHO specifications. At its meeting in 1999^[8], the Expert Committee on Vector Biology and Control recommended harmonization of the specifications development procedures and processes with those of FAO. From 2002, all specifications for technical grade active ingredients and most specifications for formulated products will be developed through the FAO/WHO JMPS, using the new procedure. As in the case of FAO specifications, a transitionary period will permit completion of specifications already in development under the old procedure.

Under the new procedure, WHO recommendations on use and WHO specifications are restricted to the data package and product evaluated by WHOPES. Where a TC/TK of a subsequent proposer has been found "equivalent" (see chapter 3) and the formulations derived from it meet all criteria of WHO specifications for the reference product, WHO recommendations on use are expected to apply. Any potential differences in safety and efficacy, due to formulation-specific properties, are determined in the small scale field studies described above.

Joint FAO/WHO specifications

In December 1999, the WHO Expert Committee on Vector Biology and Control recommended^[9] that FAO and WHO should use the same definitions nomenclatures, format and supporting methodologies for pesticide specifications. The Committee further recommended that WHO and FAO should develop joint specifications for technical materials (TC) and technical concentrates (TK) for those pesticides used in both public health and agricultural applications. In May 2000, the proposal was recommended for adoption by the FAO Panel of Experts.

In consequence, to facilitate harmonization of specifications development, in 2001, WHO and FAO signed a Memorandum of Understanding to implement the recommendations and to enable the expert committees of FAO and WHO to work together. When working together, the two expert committees will be known as the FAO/WHO Joint Meeting on Pesticides Specifications (JMPS) and the first full meeting of the JMPS was held in Rome in June, 2002. In future, it is expected that the expert committees will meet separately only where a specifications issue arises that cannot be resolved by the JMPS.

In 2001, a draft of the present FAO/WHO Manual was circulated widely by FAO and WHO, with comments invited from industry, member governments and any other interested party. In February 2002, a small drafting group of members of the FAO and WHO expert committees and industry technical experts met in York, UK, to consider all the comments received and to produce a draft for adoption by the JMPS in June 2002.

This 1^st edition of the FAO/WHO Manual incorporates guidelines for pesticide formulations for public health use, including those for microbial larvicides. In addition, new guidelines for agricultural pesticides (DC, OD, EG and EP) have been incorporated, together with various procedural refinements which have proven necessary in the light of experience since 1999.

Pesticide formulations, the specifications for them, and scientific knowledge in relation to pesticides, will continue to evolve and FAO, WHO and the JMPS welcome comments on any aspect of this 1st edition of the joint Manual.