Efficient control of residues is an essential contribution to the maintenance of a high level of consumer protection in the EU. In this respect it is necessary to provide clear rules on how laboratory analysis has to be carried out and results are interpreted.

Commission Decision 2002/657/EC of 12 August 2002 implementing Council Directive 96/23/EC establishes criteria and procedures for the validation of analytical methods to ensure the quality and comparability of analytical results generated by official laboratories. Moreover, the Decision establishes common criteria for the interpretation of test results and introduces a procedure to progressively establish minimum required performance limits (MRPL) for analytical methods employed to detect substances for which no permitted limit (maximum limit) has been established. This is in particular important for substances whose use is not authorised or is specifically prohibited in the EU.

With Commission Decision 2003/181/EC : of 13 March 2003 amending Decision 2002/657/EC as regards the setting of minimum required performance limits (MRPLs) for certain residues in food of animal origin (Text with EEA relevance)

Commission Decision 2004/25/EC : of 22 December 2003 amending Decision 2002/657/EC as regards the setting of minimum required performance limits (MRPLs) for certain residues in food of animal origin (Text with EEA relevance)

With the purpose of clarifying those aspects of the Commission Decision 2002/657/EC which could be deemed to be somewhat ambiguous and formulating recommendations to facilitate a harmonised implementation of the Decision a working group of experts from the Member States and from the Community Reference laboratories for residues drafted some guidelines. The guidelines were presented to the Standing Committee of the Food Chain and Animal Health for endorsement on 16 November 2004 and un updated version on 17 May 2006. It was also distributed through the CRL-NRL network for information. (These guidelines did not affect and invalidate validation studies that were performed in accordance with the requirements of Commission Decision 2002/657/EC).

Article 1 indent 2 of Commission Decision 2002/657/EC states that "this Decision shall not apply to substances for which more specific rules have been laid down in other Community legislation”. Since the entry into force of Decision 2002/657/EC, specific legislation on sampling, sample preparation and requirements for methods of analysis for the control of Community provisions on contaminants in foodstuffs has been published.
A new chapter has been included in the guidelines to clarify that analytical methods for the analysis of residues in food of animal origin of substances covered by Commission Regulation (EC) No 401/2006, Commission Regulation (EC) No 1883/2006 and Commission Regulation (EC) No 333/2007 do not fall within the scope of Commission Decision 2002/657/EC.

Therefore the obligation to validate analytical methods according to the requirements established in Commission Decision 2002/657/EC does not apply in so far as these more specific rules apply.

Those methods for the above mentioned group of substances which have been already validated according to Decision 2002/657/EC are considered to be valid in so far they are in compliance with the requirements laid down in the specific regulations.

Update December 2008: For some pharmacologically active substances the MRLs laid down in Community legislation are expressed in form of sum-MRLs. Examples include sulfonamides, tetracyclines, benzimidazoles, and azaperone. In these cases the question of how to validate the respective methods arose.

The objective of the revised guidelines is to add a new chapter including advice to the laboratories on how to validate the analytical methods for these substances and to assess if the results are or not compliant.

Guidelines for the implementation of Decision 2002/657/EC regarding some contaminants SANCO0895/2007
Consolidated guidelines for the implementation of Decision 2002/657/EC Updated December 2008

Update January 2010
CRLs' guidelines for the validation of screening methods for residues of veterinary medicines.

The scope of Commission Decision 2002/657/EC on the validation of screening methods is limited. This guideline document supplements Commission Decision 2002/657/EC regarding the validation of screening methods. The Community Reference Laboratory (CRL) in Fougères in collaboration with the CRL in Berlin and in agreement with the CRL in Bilthoven, and after consultation through the NRL (National Reference Laboratories) network, has drafted this document with the purpose to assist residue laboratories to validate screening methods. The guidelines covers the initial validation and also a shortened or 'abridged' validation, which under certain conditions, allows for the transfer of methods already validated in one laboratory to a second one.

Guidelines for the validation of screening methods for residues of veterinary medicines (Initial validation and transfer)