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Substance identification and naming
The REACH regulation focuses exclusively on substances. To ensure a properly working REACH system, unambiguous substance identification is thus essential.
Substances within the scope of REACH
REACH concerns the manufacture, import, placing on the market and use of substances on their own, in preparations (intentional mixtures or solutions composed of two or more substances) and articles.
Under REACH, a substance means 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.
This definition goes beyond a pure chemical compound defined by a single molecular structure.
Some substances are exempted from REACH or from parts of REACH (for more information, see table Scope of the REACH regulation).
Various types of substances
For identification and naming in REACH, substances are divided into two main groups:
Variability of composition for well defined substances is specified by the upper and lower limits of the concentration range(s) of the main constituent(s). For UVCB substances, the variability is relatively large and/or unpredictable.
When a registration is required for a “well defined substance”, it shall include the substance chemical composition, the chemical identity and the content of each constituent in the substance. For some types of substances, the chemical composition alone is not enough for characterisation and some additional physical parameters about the chemical structures have to be added to the substance identification (e.g. crystallomorphology).
“UVCB substances” require other types of information for their identification in addition to what is known about their chemical composition because:
When registration is required for an UVCB substance, manufacturers/importers shall include the name, the origin or source of the substance and the most relevant steps taken during processing. Other substance properties can also be important identifiers.
Rules for naming the various substances are given in diagram Identification and naming of substances.
Identifying equal substances
Manufacturers and importers have to determine if their respective substances may be regarded as the same for the purposes of REACH. The identification of equal substances is important in data sharing which allows for limited substance testing and is based on proper substance identification.
Grouping of structurally related substances
Under REACH, annexe XI opens the possibility of evaluating chemicals not on a one-by-one basis but by grouping chemicals in categories.