# Commission Regulation (EC) No 761/2009 of 23 July 2009 amending, for the purpose of its adaptation to technical progress, Regulation (EC) No 440/2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) (Text with EEA relevance), Division 1.5: REFERENCE SUBSTANCE

Extent: E+W+S+N.I.

Reference substance(s), such as 3,5-dichlorophenol used in the international ring test (10), may be tested as a means of checking the test procedure. It is advisable to test a reference substance at least twice a year or, where testing is carried out at a lower frequency, in parallel to the determination of the toxicity of a test substance.

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Source: https://www.legislation.gov.uk/eur/2009/761/annex/VI/division/1/division/1.5 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-761/annex-VI/division-1/division-1.5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.