Substance

Under REACH Article 3(1), a substance is a chemical element and its compounds in the natural state or obtained by any manufacturing process, including any additive necessary to preserve its stability and any impurity deriving from the process used, but excluding any solvent which may be separated without affecting the stability of the substance or changing its composition. Substances must be identified precisely for REACH purposes using agreed identifiers (molecular formula, SMILES, CAS number, EC number) and classified using Annex VI to the CLP Regulation.

REACH Regulation (EC) No 1907/2006, Article 3(1); CLP Regulation (EC) No 1272/2008.

Precise substance identification is the starting point of all REACH compliance. Manufacturers and importers must establish correct CAS/EC numbers, purity specifications, and impurity profiles for their substances. Incorrect substance identification leads to incorrect SIEF participation, duplicate registrations, and potential compliance gaps. UVCB (Unknown or Variable composition, Complex reaction products, Biological) substances require special identification protocols.