Latest update: 19/03/2024

Directive 2004/37/EC - carcinogens, mutagens or reprotoxic substances at work

The Directive addresses the protection of workers from the health and safety risks related to exposure to carcinogens, mutagens or substances toxic to reproduction (CMR) at work.

Directive 2004/37/EC of 29 April 2004 on the protection of workers from the risks related to exposure to carcinogens, mutagens or reprotoxic substances at work (Sixth individual Directive within the meaning of Article 16(1) Directive 89/391/EEC) is a single directive within the scope of the OSH Framework Directive (Directive 89/391/EEC). The Directive published in 2004 replaced Directive 90/394/EEC and its subsequent amendments (Directive 97/42/EC and Directive 1999/38/EC). Directive 2004/37/EC has undergone several changes in the period 2017-2024 to improve workers' protection against cancer, in line with the EU Commission's wider commitment to step up the fight against cancer.

Five amendments were adopted (Directive 2017/2398/EU, Directive 2019/130/EU, Directive 2019/983/EU, Directive 2022/431/EU and Directive 2024/869/EU) that introduced stricter limit values for a number of widespread carcinogens, mutagens or reprotoxic substances. Directive 2022/431/EU also brought reprotoxic substances within the scope of the directive, changing the original title on the protection of workers from the risks related to exposure to carcinogens or mutagens at work to the protection of workers from the risks related to exposure to carcinogens, mutagens or reprotoxic substances at work. The Directives have to be transposed in national laws by the EU Member States.

This Directive covers the protection of workers from health and safety risks from exposure to carcinogens, mutagens or reprotoxic substances (CMR) at work. This Directive does not apply to workers exposed to radiation for cases covered by the Euratom Treaty.
Hazardous medicinal products which contain one or several CMR fall under the scope of Directive 2004/37/EC.

- Definitions of ”carcinogen”, ”mutagen”, "reprotoxic substance", "non-threshold reprotoxic substance" and “threshold reprotoxic substance”. For these definitions reference is made to the classification according to  Regulation (EC) No 1272/2008.
- Definitions of ”limit value”, “biological limit value” and “health surveillance”


Risk assessment
The employer shall assess and manage the risk of exposure to carcinogens, mutagens or reprotoxic substances. This process shall be renewed regularly and data shall be supplied to the authorities upon request. Special attention should be paid to investigate and take account of all possible ways of exposure (including all skin-related possibilities), and to persons at particular risk.

Prevention measures
Workers' exposure must be prevented. If replacement is not possible, the employer shall use a closed technological system. The employer shall reduce the use of CMR by replacing them with a substance that is not dangerous or less dangerous. Where a closed system is not technically possible, the employer shall reduce exposure to the minimum. Exposure shall not exceed the limit value of a carcinogen, as set out in Annex III.

Wherever a CMR is used, the employer shall:

  • Limit the quantities of these carcinogens, mutagens or reprotoxic substances at the place of work;
  • Keep the number of workers exposed as low as possible;
  • Design the work processes so as to minimise the substance release;
  • Evacuate carcinogens or mutagens at source, also respecting the environment;
  • Use appropriate measurement procedures (especially for early detection of abnormal exposures in the event of unforeseeable events or accidents);
  • Apply suitable working procedures and methods;
  • Use individual protection measures if collective protection measures are not enough;
  • Provide the necessary hygiene measures (regular cleaning);
  • Keep workers informed about related issues;
  • Demarcate risk areas and use adequate warning and safety signs (including ”No smoking” signs);
  • Draw up emergency plans;
  • Use sealed and clearly/visibly labelled containers for storage, handling, transportation and waste disposal.

Employers shall make certain information available to the competent authority upon request (activities, quantities, exposures, number of exposed workers, preventive measures) and inform workers if abnormal exposure has happened.

In cases of abnormal exposure or incident, only workers essential for repairs shall be permitted to work in the affected area, and only with appropriate protection. The exposure should not be permanent and shall be minimised.
If a temporary, planned, higher exposure is unavoidable (e.g. as part of maintenance), the employer/management shall consult workers/representatives on the measures which will be taken to minimise exposure, and provide appropriate prevention, together with access control.
If there is a risk to workers, specified areas shall be made accessible solely to workers who, by reason of their work or duties, are required to enter them.

The employer shall take adequate measures to ensure proper hygiene (minimising the risk of contamination with CMR). Provisions and conditions must be free of charge for the workers, and will include:

  • The prohibition of eating/drinking/smoking in contamination risk areas
  • Provision of appropriate protective clothing
  • Provision of separate storage places for working/protective clothing and for street clothes
  • Acces to appropriate and adequate washing and toilet facilities
  • Availability of cleaned, checked and maintained protective equipment, stored in a well-defined place.

Training and information
The employer shall also provide appropriate training on potential risks to health, precautions to prevent exposure, hygiene requirements, protective equipment and steps to be taken in the case of incidents. The training has to take into account any new or changed risk. In healthcare settings, the training has to be provided on a regular basis when workers are likely to be exposed to carcinogens, mutagens or reprotoxic substances including those contained in hazardous medicinal products. To offer advice to employers and workers on how to manage exposure to hazardous medicinal products (HMPs) the European Commission has published a guidance document in 2023. The guide also serves as a useful reference point and support for training activities. 
Employers shall inform workers about installations and containers on site containing CMR, and label them clearly and legibly, together with warning and hazard signs. Employers shall inform workers and/or representatives about abnormal exposure incidents as quickly as possible.

Consultation and participation of workers
Workers and/or any workers' representatives shall be involved in the application of this Directive. Employers will keep an up-to-date list of workers exposed, and will give specified access to data to authorized persons (doctor, authorities, workers and representatives). Consultation and participation of workers shall take place in accordance with Directive 89/391/EEC.
Social Partners' agreements shall be listed on the EU-OSHA website.

Health surveillance
If a biological limit value has been set in Annex IIIa, health surveillance shall be mandatory. Workers shall be informed of that requirement before being assigned to the task involving the risk of exposure.
The Member States shall establish arrangements for health surveillance of workers if there is a risk to their health and safety (prior to exposure, at regular intervals thereafter; and even after the end of exposure - if this is requested by the responsible doctor/authority). If a worker is suspected of suffering ill-health due to exposure or if a biological limit value is found to have been exceeded, then the subsequent health surveillance of other exposed workers may be required, and the risk shall be reassessed. Individual medical records of health surveillance shall be kept.

Information and advice must be given to workers regarding any health surveillance that they may undergo following the end of exposure. Workers shall have access to the results of the health surveillance that concern them. Workers concerned, or the employer, may request a review of the results of the health surveillance. All cases of occupational cancers, adverse effects on sexual function and fertility in adult male and female workers or developmental toxicity in their offspring shall be notified to the competent authority. Records shall be kept for at least 40 years with regard to carcinogens or mutagens and for at least 5 years with regard to reprotoxic substances following the end of exposure, and transferred to the authority concerned if the firm ceases to exist. 

Member States had to comply with the 2017 amendments (Directive 2017/2398/EU) by 17 January 2020. Transitional measures (graded lowering of the limit values) apply to hardwood dusts and Chromium (VI).
Member States had to comply with the early 2019 amendments (Directive 2019/130/EU) by 21 February 2021. Special deadlines apply to Diesel engine exhaust emissions: the limit value of 0,05 mg/m3 measured as elemental carbon may, should be reached after additional transitional periods (in addition to the transposition period) of 2 years respectively of 5 years for the sectors of underground mining and tunnel construction.
Member States had to comply with the mid-2019 amendments (Directive 2019/983/EU) by 11th July 2021. Transitional higher limit values for cadmium and beryllium shall apply until 11th July 2027. For the copper smelting sector, the limit value for arsenic shall apply only from 11th July 2023. A transitional higher limit value for formaldehyde shall apply in the health care, funeral and embalming sectors until 11th July 2024.
Member States have to comply with the 2022 amendments (Directive 2022/431/EU) by 5 April 2024. Transitional higher limit values shall apply for Benzene, Acrylonitrile and Nickel compounds.
Member States have to comply with the 2024 amendments (Directive 2024/431/EU) by 9 April 2026. Transitional higher biological limit values shall apply for Lead and its inorganic compounds.


ANNEX I: List of substances, mixtures and processes

  1. Manufacture of auramine.
  2. Work involving exposure to polycyclic aromatic hydrocarbons present in coal soot, coal tar or coal pitch.
  3. Work involving exposure to dusts, fumes and sprays produced during the roasting and electro-refining of cupro-nickel mattes.
  4. Strong acid process in the manufacture of isopropyl alcohol.
  5. Work involving exposure to hardwood dusts.
  6. Work involving exposure to respirable silica dust generated by a work process
  7. Work involving dermal exposure to mineral oils that have been used before in internal combustion engines to lubricate and cool the moving parts within the engine.
  8. Work involving exposure to diesel engine exhaust emissions.

ANNEX II: Practical recommendations for the health surveillance of workers

ANNEX III:  Limit values and other directly related provisions

Binding limit values for 41 carcinogenic, mutagenic or reprotoxic agents (CMR). Most of these binding limit values were introduced or made more stringent by the four amendments to the Directive in the 2017-2024 timeframe. For some of the limit values transitional periods apply. 

In 2017 binding limit values and skin notations were reviewed/set for the following agents ("1st step"):

  • Hardwood dusts
  • Chromium (VI) compounds
  • Refractory ceramic fibres
  • Respirable crystalline silica dust
  • Benzene
  • Vinyl chloride monomer
  • Ethylene oxide
  • 1,2-Epoxypropane
  • Acrylamide
  • 2-Nitropropane
  • o-Toluidine
  • 1,3-Butadiene
  • Hydrazine
  • Bromoethylene

In early 2019 binding limit values and skin notations were reviewed/set for the following agents ("2nd step"):

  • Trichloroethylene
  • 4,4′-Methylenedianiline
  • Epichlorohydrine
  • Ethylene dibromide
  • Ethylene dichloride
  • Diesel engine exhaust emissions
  • Polycyclic aromatic hydrocarbons mixtures, particularly those containing benzo[a]pyrene, which are carcinogens within the meaning of this Directive
  • Mineral oils that have been used before in internal combustion engines to lubricate and cool the moving parts within the engine

In mid-2019 binding limit values, skin and sensitisation notations were set for the following agents ("3rd step"):

  • Cadmium and its inorganic compounds
  • Beryllium and inorganic beryllium compounds
  • Arsenic acid and its salts, as well as inorganic arsenic compounds
  • Formaldehyde
  • 4,4′-Methylene-bis (2-chloroaniline) – MOCA

In March 2022 binding limit values, skin and sensitisation notations were reviewed/set for the following agents ("4th step"):

  • Benzene
  • Acrylonitrile
  • Nickel compounds
  • Inorganic lead and its compounds
  • N,N-Dimethylacetamide
  • Nitrobenzene
  • N,N Dimethylformamide
  • 2-Methoxyethanol
  • 2-Methyoxyethyl acetate
  • 2-Ethoxy ethanol
  • 2-Ethoxyethyl acetate
  • 1-Methyl-2-pyrrolidone
  • Mercury and divalent inorganic mercury compounds including mercuric oxide and mercuric chloride (measured as mercury)
  • Bisphenol A; 4,4′-Isopropylidenediphenol
  • Carbon monoxide

In March 2024 lower binding limit value and 'Non-threshold reprotoxic substance' notation ("5th step") for:

  • Lead and its inorganic compounds

ANNEX IIIa: Biological limit value and health surveillance measures 
Directive 2022/431/EU introduced a binding biological limit for lead as well as the exposure values that make health surveillance mandatory.
Directive 2024/431/EU lowered the binding biological limit for lead and introduced more restrictive health surveillance with regard to female workers of childbearing age.

ANNEX IV: Repealed Directive and its successive amendments

ANNEX V: Correlation table

Read the full text of Directive 

National laws implementing this Directive


Further information