The European Community has regulations concerning the classification and labelling of dangerous preparations and substances.
A product’s classification determines the dangers presented by a substance or preparation from a health and environmental standpoint, and with respect to its physical and chemical properties.

Directive 67/548/CEE and its subsequent adaptations define various risks (R risk phrases) and precaution advice (S safety phrases) that are used to classify a substance or preparation according to how dangerous a chemical is.
In Appendix I of Directive 67/548/CE, approximately 3500 substances are listed with a harmonised European classification. The latest adaptation of the directive (29th ATP) was published on 30th April 2004.
Toxicology and Eco-toxicology tests are performed on these substances in order to assign an official classification to the pure (non-diluted) form of the substance. These substances then have an INDEX number (see Substance Codification) assigned to them.

Label calculation, applying the calculation rules defined in Directive 1999/45/CE and its subsequent adaptations, can be used to define the various types of danger that substances and preparations may present, as well as precaution advice related to these risks.

A product’s label provides the user with various types of information, such as:

- The danger symbols
- “R” risk phrases: Nature of the specific risks attributed to the substances or preparations.
- “S” safety phrases: Precaution advice regarding the substances and preparations.
- Data specific to certain products (e.g. detergents, biocides)

In the years to come, Directive 67/548/CE and 1999/45/CE regarding the classification and labelling of substances or preparations will be replaced by the General Harmonised System (GHS).