OECD Considers Animal Welfare
in the Development of Test Guidelines
Over 25 years ago, the OECD recognised the need to protect animals in general and in particular those used in experimental work. The Second High Level Meeting of the Chemicals Group addressed this ethical issue and adopted the following statement:
"The welfare of laboratory animals is important; it will continue to be an important factor influencing the work in the OECD Chemicals Programme. The progress in OECD on the harmonisation of chemicals control, in particular the agreement on Mutual Acceptance of Data (MAD), by reducing duplicative testing, will do much to reduce the number of animals used in testing. Such testing cannot be eliminated at present, but every effort should be made to discover, develop and validate alternative testing systems".
The MAD Council Decisions have had a major impact on testing practices. MAD states that data generated in the testing of chemicals in an OECD member country in accordance with OECD Test Guidelines and OECD Principles of Good Laboratory Practice (GLP), shall be accepted in other member and adhering non member countries for purposes of assessment and other uses relating to the protection of man and the environment. These proactive Council Decisions still save thousands of animals every year and an increasing number of non OECD economies adhere to MAD.
The OECD is committed to the implementation of the 3R-principles (Replacement, Reduction and Refinement), as first laid down by Russel & Burch in 1959, in their “The Principles of Humane Experimental Technique”. Since the adoption in 1981 of the first set of Test Guidelines, many of the short-, and long-term toxicity tests ,[Table 1] as well as the genetic toxicity tests, [Table 2] have been developed or revised to introduce aspects of the 3R-principles. The most noteworthy achievement is probably the deletion of the much criticised Test Guideline 401 on Acute Toxicity Testing, and its replacement with Test Guidelines 420, 423 and 425, introducing reduction and refinement. Other examples are the Local Lymph Node Assay (Test Guideline 429) introducing refinement and reduction compared to Test Guideline 406 and the Test Guideline 428 on “Skin Absorption: In Vitro Method” offering an alternative method to Test Guideline 427, among others.
Another example of the commitment of the OECD to implement the 3R-principles into regulatory toxicity testing is the development of the Guidance Document No.19 on “the Recognition, Assessment and Use of Clinical Signs as Humane Endpoints for Experimental Animals Used in Safety Evaluations” from 2000. Guidance Document 19 gives practical guidance how to apply the 3R-principles, with an emphasis on Refinements when performing OECD Test Guidelines.
To establish whether a new test method is suitable for a given regulatory purpose, it needs to go through a validation study. In 1996, an OECD workshop was held in Solna, Sweden, on the harmonisation of validation principles and criteria for regulatory acceptance of alternative test methods. This meeting was very successful and was followed by several other expert meetings but it was not until 2005 that member countries could adopt the Guidance Document No. 34 on “the Validation and International Acceptance of New or Updated Test Methods for Hazard Assessment”. Guidance Document 34 provides the principles and criteria for how validation studies of new or updated test methods should be performed. It is a document of central animal welfare importance since it emphasises a harmonised approach towards validation of all sorts of different tests, including new alternative test methods. As a result of the adoption of Guidance Document 34, a considerably more harmonised validation and regulatory acceptance procedure has been achieved at the OECD and a number of new Test Guideline proposals with animal welfare aspects are under development. [Table 3]].