This part of the European Standard EN 71 specifies requirements for the maximum amount of certain substances and preparations used in experimental sets for chemistry and related activities. These substances and preparations are - chemicals classified as dangerous by the Directives on dangerous substances [1] and dangerous preparations [2] (including substances which have been self-classified according to the requirements of these Directives), - substances and preparations which in excessive amounts may harm the health of the children using them but which are not classified as dangerous by the above mentioned Directives and - any other chemical substances and preparations delivered with the toy. This standard applies to chemistry sets and supplementary sets. It also covers toys for experiments within the fields of mineralogy, biology, physics, microscopy and environmental science whenever they contain one or more chemical substances and/or preparations. It also specifies requirements for marking, contents list, instructions for use and for equipment intended for carrying out the experiments. Other chemical toys are specified in EN 71-5. NOTE The terms “substance“ and “preparation“ as used in directives 67/548/EEC [1] and 1999/45/EC [2] are also used in the “REACH Regulation” Regulation (EC) No 1907/2006 [4]. This regulation requires that account be taken of the emerging international standards in the regulation of chemicals such as the Globally Harmonised System (GHS) of classification and labelling of chemicals. The EU has now proposed a timetable for the introduction of GHS and it is expected that the two above mentioned directives will be repealed on 1 June 2015. In the GHS regulation the term 'mixture' rather than 'preparation' is used. Preparations and mixtures should be considered synonymous; both are mixtures or solutions of substances that do not react with each other.