Referral from the Codex Committee on Residues of Veterinary Drugs in Foods (CCRVDF) - Establishing Routine Methods to Meet Codex Maximum Residue Limit Requirements
11. The Committee at its 20th Session had agreed to: accept the criteria-based approach in principle; draw up detailed working guidelines for the operation of the criteria approach by the Committee, including the definitions and selection of the criteria to be used; clarify the procedures to be used in the dispute situation; and emphasize that procedures were to be used to ensure that laboratories are 'in control' and operating proficiently in all cases. The Committee had also agreed that there should be a clear indication that the problems related to Type II/Type III classification were not deliberately dealt with. The Committee had requested the Delegations of the United Kingdom and Canada to prepare a paper on working procedures for the new approach in horizontal manner, using Codex general methods for contaminants as examples for consideration at the current Session[6].
12. The Delegation of the United Kingdom presented the paper and stressed that this new approach was not intended to downgrade methods of analysis for Codex purposes; methods must still be collaboratively studied. In the new approach, Type I would remain the same as it was felt that the number of Type I methods submitted for endorsement would decrease and development of new Type I methods would be very limited in the future; whereas Type II/Type III methods would be converted into criteria as new proposals were submitted by Codex Committees. The Delegation introduced a set of selection criteria; assessment of the acceptability of the precision characteristics of a method; and two steps to be taken in cases of trade disputes. The examples of the conversion from methods to criteria using Codex general methods were explained. The Delegation indicated that five years experience in the UK with this approach had not cause significant problems.
13. A majority of delegations welcomed and supported this approach. Several delegations proposed that "detection limit" and "determination limit" be deleted from the selection criteria as they were more related to laboratory equipment than method per se. Some delegations stated that the paper should specify that this approach was applicable to chemical analysis.
14. The Delegations of the
United States and France stated that how to deal with trade dispute situations
was not fully addressed. The Delegation of the United States stated while the
"criteria"-based approach was acceptable for Type III methods, it was not for
Type II methods because they were needed in cases of trade disputes. The
Delegation of France offered to prepare a paper on trade dispute
situations.
15. The Committee agreed that the paper should be revised by the Delegations
of Canada, France and the United Kingdom, with corrections as appropriate, for
circulation to Member Countries and international organizations for comments.
Other delegations were invited to provide comments for the redrafting directly
to the Delegation of the United Kingdom as soon as possible. The document would
be further revised based on comments received in response to the circulated
text for consideration by the Committee at its next Session. It was recognized
that the terms and definitions used for criteria should be harmonized with those
in the list of Analytical Terminology for Codex Use[7]
(see para. 28.).
16. The CCRVDF referred to this Committee a paper on establishing routine methods to meet Codex Maximum Residue Limit requirements as it had felt that the content of the document had important implications for this Committee[9]. The CCRVDF was having difficulties selecting methods in relation to method validation by collaborative studies. The Delegation of Australia presented Appendix of CX/MAS 97/3-Add.1 explaining that in the case of veterinary drug residue analysis it was not possible to perform large scale method validations, a significant number of methods had not been collaboratively studied, and there would be more problems in the future. It was further stated that increasing use of third party laboratories would lead to problems concerning the use of proprietary methods. It was proposed that performance-based methods be utilized.
17. It was pointed out that until now this Committee had primarily dealt with compositional standards. As the levels of contaminants and residues were orders of magnitude lower than those of specifications contained in compositional standards, it was necessary to take variability into consideration and special consideration be given to sampling. It was recognized that there was a conflict between the Protocol[10], recommended by this Committee and adopted by the Commission, and practical problems in some Codex Committees. It was realized that this problem had not been considered so far by this Committee and that there might be a need to address this problem at future Sessions of the Committee.
18. The Committee
supported the proposal of the CCRVDF that the Commission request FAO and
WHO to give consideration to convening an expert consultation on the question of
methods validation for food control purposes.
19. The Delegation of the United Kingdom proposed to commence a new work item
on the concept of in-house method validation based on international general
guidelines. It was stated that a number of countries had already established
instructions on this matter. Several delegations supported this proposal. The
Delegation of the United Kingdom stated that criteria contained in Recommendation
6a of the paper would be taken into consideration in the redrafting of the paper
on a "criteria"-based approach (see para. 15.). The Delegation of the United
States added that variability should be included in the criteria.
