The European Commission (EC ) has issued a technical directive restricting the use of 24 chemical substances in hair dyes. The restrictions set maximum authorized concentrations of the substances and other limitations on their use. In an ongoing assessment conducted by the EC , 181 substances have already been banned in hair dyes, and restricted-use conditions placed on 52 substances. European Union member states are required to adopt the new restrictions by March 1, 2013, and to apply them starting September 1, 2013.