著者

小野 宏

出版者

日本環境変異原学会

雑誌

環境変異原研究 (ISSN:09100865)

巻号頁・発行日

vol.27, no.2, pp.133-137, 2005-07-31

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The OECD established the Guidelines for Testing of Chemicals in 1981, which is the basis of the mutual acceptance of data (MAD) system among the member countries to prevent unnecessary repetition of toxicity tests, and consequently to reduce the number of animals used. The Guidelines was soon subjected to revision from the viewpoint of animal welfare besides its periodical updating with the state-of-art in the toxicological sciences. Revision of the Test Guidelines is in progress according to the 3Rs principle, reduction, refinement and replacement. The acute toxicity test and the skin and eye irritation/corrosion tests were assumed to be the most problematic ones among the animal tests in animal welfare aspect. Three different test methods have been adopted for the alternative to acute oral toxicity test (Test Guideline (TG) 401), namely, the fixed dose procedure (TG420), acute toxic class method (TG423) and up-and-down procedure (TG425), and the reduction of animals was accomplished. Then the traditional acute oral toxicity test (TG401) has been deleted from the Guidelines. Procedures for irritation/corrosion tests for skin (TG404) and eye (TG405) were reorganized into tier-test system in order to prevent any corrosion or strong irritation to take place. The tier system consists of survey of toxicities of the test chemical, structure-activity relationship, pH, and testing with in vitro methods. Moreover, at the final tier animal testing should proceed by one animal. Three kinds of in vitro corrosivity tests have been adopted in the Guidelines.