Carcinogenic, mutagenic and reprotoxic substances (CMRs)
Definition and regulatory framework
Chemical substances, singly or combined in mixtures, may have various harmful effects on human health. Some of them may be carcinogenic, mutagenic or reprotoxic. In this case they are categorised as “CMRs”. In view of the hazards they present, these classified substances and mixtures are subject to restrictive regulations, particularly in the workplace. Discover what these substances are and how they are regulated.
Chemical substances, singly or combined in mixtures, may have various harmful effects on human health. Some of them are categorised as “CMRs” because they are carcinogenic, mutagenic or reprotoxic. These terms are defined by regulations [1]:
- carcinogens (C): substances and preparations which, if they are inhaled or ingested of if they penetrate the skin, may induce cancer or increase its incidence;
- mutagens (M): substances and preparations which, if they are inhaled or ingested or if they penetrate the skin, may induce heritable genetic defects or increase their incidence;
- reprotoxins (R): substances and preparations which, if they are inhaled or ingested or if they penetrate the skin, may produce or increase the incidence of non-heritable adverse effects in the progeny and/or an impairment of male or female reproductive functions or capacity.
How are these substances controlled from a regulatory perspective?
Although there are several chemical classifications for regulating these substances and their use in terms of their CMR properties, only one of these classifications is included in a regulation.It is the Europeanclassification provided for under what is referred to as the CLP Regulation (for Classification, Labelling and Packaging) [2]. This Regulation, and thus the classification it contains, is directly applicable in all Member States of the European Union,including France. The CLP Regulation introduced hazard categories that define the level of evidence for the observed CMR effect. Thus, two categories (1 and 2) are defined: Category 1 and Category 2. Category 1 is further divided into two subcategories (1A and 1B).
| Effects / Hazard Class | Categories | Category definitions |
| Carcinogens | Category 1A | Substances known to have carcinogenic potential for humans. |
| Category 1B | Substances presumed to have carcinogenic potential for humans. | |
| Category 2 | Substances suspected of having carcinogenic potential for humans. | |
| Mutagens | Category 1A | Substances known to induce hereditary mutations in the germ cells of humans. |
| Category 1B | Substances presumed to induce hereditary mutations in the germ cells of humans. | |
| Category 2 | Substances of concern because they could induce hereditary mutations in the germ cells of humans. | |
| Reprotoxins | Category 1A | Substances known to be toxic for human reproduction. |
| Category 1B | Substances presumed to be toxic for human reproduction. | |
| Category 2 | Substances suspected of being toxic for human reproduction. |
Substances having undergone harmonised European CMR classification are listed in Annex VI of the CLP Regulation. This annex also lists the classifications harmonised at the European level and is updated regularly on the basis of developments in scientific knowledge.
Substitution as the first measure of protection
The prevention of chemical risk in the workplace is based primarily on the replacement of a hazardous product with a non-hazardous or less harmful product (substitution).Thus, for hazardous chemicals and CMR category 1A or 1B chemicals, the search for a substitute is a requirement for employers [3] and supersedes all other measures for risk reduction, when the risk cannot be excluded.
Thus, the employer must be able to justify successful or unsuccessful approaches undertaken for the substitution of all CMR categories 1A and 1B agents or processes documented in the workplace. The result of these investigations should, in particular, be included in the master risk assessment document. Only a technically sound argument is admissible to justify any failure to substitute a CMR category 1A or 1B substance or process by a less hazardous or non-hazardous agent or process.
What is the extent of CMR exposure?
The list of CMR chemicals used in France in 2005, drawn up by INRS [4], estimates the annual consumption of 324 different CMR chemicals and several hundred petroleum derivatives. In 2005, 4.8 million tons of CMR chemicals were therefore used in France.
For example:
For formaldehyde (currently classified as a category 2 carcinogen by the European Union):
- an estimated 125,000 tons are consumed per year;
- it is used in a large number of sectors;
- an average of 42,000 employees are potentially exposed (some sectors such as hospitals or anatomical pathology laboratories are not counted).
While for 1,2-dichloroethane (classified as a category 1B carcinogen by the European Union):
- an estimated 1,500,000 tons are consumed per year;
- it is mainly used in the synthesis of the vinyl chloride monomer;
- an average of 5,000 employees are potentially exposed.
The SUMER survey (Medical Surveillance of Occupational Risks), conducted in 2002-2003 under the auspices of the French Ministry of Labour, also showed that a large number of employees are regularly exposed to one or more CMRs during their occupational activities.
SUMER provides an estimate of employee occupational exposure. With regard to CMR chemicals, it showed that:
- 2,370,000 employees may be exposed in their workplace to one or more carcinogenic substances, or 13.5 % of employees. Even though the use of collective protection methods has spread, exposure to carcinogenic substances has slightly increased since the last survey conducted in 1994;
- Approximately 186,000 employees (1.1 %) may be exposed to mutagenic substances and almost 180,000 (1 %) to reprotoxic substances.
The 2002-2003 SUMER survey also showed that CMR exposure is unevenly controlled. For example, 23% of exposures to benzene (excluding fuels) -whose role in the emergence of leukaemia has long been established -would be unlikely to benefit from any collective protection methods.
[1] Article R4411-6 of the French Labour Code
[2] European Regulation(EC) No. 1272/2008
[3] See Article L. 4122-2 of the French Labour Code and Articles R. 4412-15 and R. 4412-66 transposing the substitution requirement established by the European Directives.
[4] The French National Research and Safety Institute for the Prevention of Occupational Accidents and Diseases