CMR substances are chemicals that have been officially classified as Carcinogenic, Mutagenic or Toxic to Reproduction (reprotoxic), under the GB Classification, Labelling and Packaging (GB CLP) Regulation. Official classification follows a review overseen by the UK Chemicals Agency.
The classification is based on the hazardous properties a substance might have under a "worst case" situation and does not take account of whether there is any risk associated with specific uses or exposures.
CMR substances are classified as Category 1A, 1B or 2. The different categories may be simply defined as:
- Category 1A: The substance is known to be carcinogenic/mutagenic/reprotoxic to humans;
- Category 1B: The substance is presumed to be carcinogenic/mutagenic/reprotoxic to humans;
- Category 2: Substances, which cause concern for humans owing to possible carcinogenic/mutagenic/reprotoxic effects.
Category 1A and 1B substances are banned from use in cosmetic products unless they can meet all four of the following criteria:
- They comply with specific food safety requirements;
- There are no suitable alternative substances available;
- The application is made for a particular use of the products category with a known exposure;
- They have been evaluated by the European Commission's Scientific Committee on Consumer Safety (SCCS) and found safe.
Substances classified as CMR category 2 are banned in cosmetic products unless a special exemption has been granted following an in-depth safety review by independent expert scientists.
This is not as strange as it may seem, and should not cause alarm. The CMR properties may only be seen under specific circumstances or exposure conditions and so it is possible to define conditions of use and exposure that do not constitute a risk of harm to human health. It must be emphasised that the classification system does not assess risk and neither does it take account of potency.
There are stringent UK rules that cover the manufacture of cosmetic products. These require that all cosmetic products must be safe.