The European Commission (EC ) recently adopted more stringent rules for the use of animals in scientific tests as required by Regulation No. 1907/2006 concerning the registration, evaluation, authorization, and restriction of chemicals (RE ACH ). Effective July 7, 2012, Regulation No. 640/2012 is part of an effort to conform animal testing in the European Union (EU ) to Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010, which provides for “the protection of animals used for scientific purposes,” and Council Directive 86/609/EEC “regarding the protection of animals used for experimental and other scientific purposes.” In particular, the updated regulation describes the preferred in vivo method, the Local Lymph Node Assay test using mice, as an alternative to testing using guinea pigs.