The Basics What is a Substance

REACH regulates substances , so a definition of substance is a starting point for this discussion because the chemical identity issues under discussion are for substances as defined under REACH  

A second issue, which has been controversial, involves registration of certain multi-constituent substances. Directive 67/548/EEC regulated the placing of substances on the market, which meant that a multi-constituent substance was covered by the European Inventory of Existing Chemical Substances (EINECS) if all the individual constituents were listed. Therefore, if A reacts with B to 

---