Carcinogens are chemicals that may cause cancer. This happens because the chemical disturbs the normal functioning of the cell it interacts with. Exposure to carcinogens can happen, for example, when they are breathed in or come into contact with the skin.

Some carcinogens are more harmful than others. The Classification, Labelling and Packaging (CLP) Regulation divides them into three categories:

• 1A – chemicals that are known to cause cancer to humans;
• 1B – chemicals that are presumed to cause cancer to humans; and
• 2 – chemicals that are suspected of causing cancer to humans.

Although classified as known or presumed to cause cancer to humans, chemicals such as benzene, cadmium, cobalt, tricholoroethylene, formaldehyde and hexavalent chromium and its compounds are still present or being used in European workplaces. People can also be exposed to carcinogens through products containing them above certain limits.

In addition to direct exposure to the chemical itself, certain processes may also expose people to carcinogens – this can happen, for example, when breathing in fine dust from hardwood at sawmills or inhaling fumes of polycyclic aromatic hydrocarbons (PAHs) from asphalt roads at roadworks.

ECHA provides information to decision makers so they can take action to remove chemicals that may cause cancer from the market or control their use. The Agency also contributes to protecting human health and the environment from chemicals that are carcinogenic, mutagenic or toxic to reproduction (CMRs) through different legislative processes.

Dossier evaluation under REACH

ECHA checks that companies submit the information required by REACH when they register their chemicals to gain access to the EU market. This information is used to determine if a chemical could be harmful for human health or the environment, and helps decision makers to manage the possible risks.

Substances of very high concern (SVHCs) under REACH

CMRs are SVHCs that should progressively be replaced by less harmful alternatives or technologies. Member States and ECHA, at the request of the Commission, are responsible for proposing chemicals to be identified as SVHCs.

In January 2023, the Candidate List of SVHCs contained altogether 233 substances – 107 suspected to be carcinogens, mutagens or both. From this list, the Commission selects chemicals to be placed on the Authorisation List.

Harmonised classification and labelling

CMRs should have harmonised classification and labelling (CLH) throughout the EU. This means that companies that supply the substances onto the EU market have to classify and label them in the same way – as well as any mixtures containing the substances – to ensure a high level of protection for people.

Chemicals classified throughout the EU as causing cancer (categories 1A and 1B) are not allowed to be sold to consumers. But mixtures containing these chemicals can still be sold to consumers as long as their concentration in the mixture is below given limits.

In 2022, 1 151 chemicals had a harmonised classification and labelling for carcinogenicity. 

REACH authorisation

Companies need to apply for authorisation if they want to continue using carcinogens and other SVHCs that have been added to the Authorisation List. The authorisation can only be granted by the Commission if the benefits of continued use are higher than the remaining risks and no suitable alternatives are available for the applicant.

The following carcinogens need authorisation before they can be used:

• Hexavalent chromium including many of its compounds;
• Lead chromate and lead chromate pigments;
• Diarsenic trioxide and arsenic acid;
• Trichloroethylene;
• 1,2-dichloroethane (EDC);
• MOCA;
• Technical MDA; and
• Coal tar pitch, high temperature; anthracene oil (because they contain polycyclic aromatic hydrocarbons (PAHs)).

Due to the authorisation requirement related to these substances, it is estimated that some 3 000 workplaces in the EU have reduced risks to workers either by enhanced risk management measures or by replacing the chemicals with safer alternatives.

REACH restrictions

Chemicals that cause cancer are banned in the EU for consumer uses if they are present in a substance or in a mixture above a certain limit. Once a chemical gets a harmonised classification as a known or presumed carcinogen, the European Commission adds it to the list of REACH restrictions through a fast-track restriction procedure. The procedure also allows the Commission to ban the presence of carcinogens in articles – an example of this is the restriction of CMRs in clothing, textiles and footwear, which has applied since November 2020.

In addition, all types of CMRs can be restricted through the normal REACH restriction process, which includes an assessment of risks by ECHA’s Committee for Risk Assessment (RAC) and of impacts to society by the Committee for Socio-economic Analysis (SEAC).

There are already restrictions of cancer-causing chemicals in place under REACH including:

• Eight PAHs restricted in rubber and plastic articles, such as sports equipment, household utensils, clothing and footwear since January 2010 and in rubber granules and mulches used as infill on artificial sports pitches and playgrounds as of August 2022;
• 1,4-dichlorobenzene restricted in toilet fresheners since June 2015; and

• More than 4 000 hazardous substances, including CMRs, restricted in tattoo inks and permanent make-up as of 4 January 2022.

The proposal to restrict formaldehyde and formaldehyde releasers in articles that may lead to exposure of the general public was adopted by the Commission in July 2023 and the restriction starts applying after 6 August 2026.

In addition, ECHA has collected and summarised information on whether CMR substances may be present in childcare articles. This work will help the Commission to prepare a restriction proposal on CMRs in childcare articles. 

Occupational exposure limits (OELs)

Occupational exposure limits are introduced for carcinogens and mutagens to protect the health of workers in the EU. They are mainly intended to prevent workers from inhaling chemicals. It is estimated that OELs can save the lives of more than 100 000 workers over the next 50 years.

RAC has provided the Commission with scientific opinions on OELs since 2019. For example, in December 2022, RAC adopted opinions concerning cobalt and inorganic cobalt compounds, and polyaromatic hydrocarbons (PAHs). In June 2020, it adopted opinions on lead and its compounds as well as on diisocyanates.

Already in 2017, the committee developed scientific assessments on the OELs for the five following carcinogenic substances in a pilot project requested by the Commission:

• 4,4'-methylene-bis-[2-chloroaniline](MOCA);
• arsenic acid and its inorganic salts;
• benzene;
• nickel and its compounds; and
• acrylonitrile.

As ECHA had already worked on the authorisation applications of MOCA and arsenic acid, it could quickly propose the relevant OELs.

Grouping approach

To identify chemicals of concern (including CMRs) more quickly, ECHA has started to examine chemicals in groups, instead of looking at individual substances. This approach is expected to speed up the risk management of chemicals and help avoid regrettable substitution.

ECHA's database on chemicals

ECHA also maintains the world’s largest database on chemicals. The possible properties of concern – for example, if they are CMRs – are indicated for each chemical in the database.