About chemical identification in CLP

Chemicals are identified in two ways in CLP, depending on whether they are substances or mixtures.

The overall principles of chemical identification within CLP are to make sure that a substance is correctly and unambiguously identified, that a mixture is correctly and unambiguously identified, and that component substances in mixtures are correctly identified.

This is so the hazards of the product can be identified and explained to the end user; and that anyone using the substance or mixture in a new mixture has the correct information to be able to classify their mixture correctly.

Substance identification in CLP

Substances are identified on a CLP label by a recognised chemical name, and a recognised chemical identification number.

• The chemical name can be the full IUPAC chemical name, or another widely-recognised chemical name.  See https://ttenvironmenta.wpengine.com/clp-knowledgebase/chemical-names/.
• The chemical identification number, which can be either the CAS number (see https://ttenvironmenta.wpengine.com/clp-knowledgebase/cas-numbers/ ), the EC number (see https://ttenvironmenta.wpengine.com/clp-knowledgebase/ec-numbers/ ) or the Index number (see https://ttenvironmenta.wpengine.com/clp-knowledgebase/index-numbers/).

If the substance contains impurities which affect the health hazard CLP classification of the substance, these can also be identified by putting their chemical names next to the chemical name, as “contains xxxx, yyyyy”, in a similar way to mixtures (see below).   For substances identified as “contains”, no chemical identification number is required on the label.

Historically, many companies have sold substances under trade names.  In the UK, it is possible to use a trade name to identify a substance on a CLP label, but only if a recognised chemical name is also present, and the trade name is not more prominent than the chemical name.

If you are selling a substance into another EU state, and wish to identify it with a trade name should contact the state’s Competent Authority to see what their local rules are.

About chemical identification numbers

Only the CAS, EC or Index number are recognised for CLP identification purposes, that is to identify the actual substance, and its structure.

Other chemical numbers such as REACH registration numbers and authorisation numbers have been created for administrative reasons, not to identify the chemical per se, and are discussed separately at https://ttenvironmenta.wpengine.com/clp-knowledgebase/reach-registration-numbers/  and https://ttenvironmenta.wpengine.com/clp-knowledgebase/reach-authorisation-numbers/ respectively.

There are also sets of trade numbers, such as the Colour Index numbers, and although these cannot be used as identifying numbers, the Colour Index names can be used for CLP naming purposes, see https://ttenvironmenta.wpengine.com/clp-knowledgebase/colour-index-names-and-numbers/ .

According to the Chemical Abstract Service, its substance list contains around 130 million unique organic and inorganic chemical substances, such as alloys, coordination compounds, minerals, mixtures, polymers and salts, although many of the polymer families will have a single CAS number.  There are approximately 106,200 EC numbers; 14000 REACH registration numbers, and around 4,000 substances with Harmonised Classifications (that hold an Index number).  Of course, it is possible for a chemical not to be registered on any database, and it is likely that the number of chemicals known to science will continue to increase.

Mixture identification in CLP

Mixtures are identified on a CLP label by a trade name, and any component substances which affect the health hazard classification of the mixture.  These component substances are identified by putting their chemical names next to the chemical name, as “contains xxxx, yyyyy”. For substances identified as “contains”, no chemical identification number is required on the label.

For information on other companies’ trade names, see https://ttenvironmenta.wpengine.com/clp-knowledgebase/chemical-trade-names/ .

For information on which substances need to be identified under “contains” on the label, see https://ttenvironmenta.wpengine.com/clp-knowledgebase/mixture-components-identified-on-clp-label/ .

Chemicals in mixtures are required to be identified in more detail on the SDS than on the CLP label.  For more information, see https://ttenvironmenta.wpengine.com/clp-knowledgebase/mixture-components-identified-on-sds/ .

From 2020, some mixtures may also be required to be identified with a Unique Formulation Identifier, on both the label and the SDS, see https://ttenvironmenta.wpengine.com/clp-knowledgebase/unique-formulation-identifier-number/.

It is possible to claim confidentiality for low-hazard substance components in a mixture, and this is discussed here: https://ttenvironmenta.wpengine.com/clp-knowledgebase/mixtures-with-confidential-component-substances/ .