Carcinogens and Mutagens at Work: Duties, Risk Assessment and Prevention

Occupational cancer is the leading cause of work-related death in the European Union: more than 100,000 fatalities every year, as recognised in the EU Roadmap on Carcinogens and reported by EU-OSHA. It is neither a residual risk nor one confined to heavy chemical industry.

How widespread is exposure

EU-OSHA's Workers' Exposure Survey (WES), carried out between September 2022 and February 2023 in six Member States (Germany, Ireland, Spain, France, Hungary and Finland) and representative of 98.5 million workers, estimated probable exposure to 24 known cancer risk factors. Key findings from the final overview report released in December 2025:

• 46.6 million workers were probably exposed to at least one of the factors during their most recent working week;
• 11.1% of workers are exposed to at least one of the substances at a high level;
• 26.1% were probably exposed to at least two risk factors within the same week;
• the most common exposures are solar ultraviolet radiation, diesel engine exhaust emissions, benzene, respirable crystalline silica and formaldehyde.

The survey also flags serious prevention gaps: more than two-thirds of workers exposed to diesel engine exhaust during vehicle maintenance reported taking no protective measures at all.

How a carcinogen is classified

Two systems coexist and should not be confused.

The CLP Regulation classifies substances by hazard using harmonised categories: Carc. 1A, 1B and 2 for carcinogenicity, Muta. 1A, 1B and 2 for germ cell mutagenicity, Repr. 1A, 1B and 2 for reproductive toxicity. This is the classification that appears on labels and safety data sheets, and the one referenced by worker protection legislation.

IARC, the WHO agency, instead evaluates scientific evidence and places agents in four groups: Group 1 (carcinogenic to humans), 2A (probably carcinogenic), 2B (possibly carcinogenic) and 3 (not classifiable). Group 4 was removed in the 2019 revision of the Preamble and merged into Group 3. Crucially, IARC identifies a hazard; it does not quantify the risk at a given level of exposure.

The EU framework

Directive 2004/37/EC is the common European reference. It has been amended several times; the sixth amendment, Directive (EU) 2022/431, significantly broadened its scope:

• it extends the scope to reprotoxic substances, hence the CMRD acronym;
• it extends health surveillance and the keeping of lists of exposed workers to those substances, with records kept for at least five years after the end of exposure;
• it is accompanied by a Commission statement confirming that hazardous medicinal products containing one or more carcinogenic, mutagenic or reprotoxic substances also fall within the scope. The transposition deadline was 5 April 2024.

More recently, Directive (EU) 2024/869 of 13 March 2024 amended both Directive 2004/37/EC and Directive 98/24/EC, revising the limit values for lead and its inorganic compounds and introducing the first EU limits for diisocyanates.

The Italian framework: Title IX, Chapter II

In Italy the subject is governed by Legislative Decree 81/2008 (D.Lgs. 81/08), Title IX, Chapter II, now titled "Protection from carcinogens, mutagens or reprotoxic substances" following transposition by Legislative Decree 135 of 4 September 2024. The structure:

• Art. 233 scope, Art. 234 definitions;
• Art. 235 substitution and reduction;
• Art. 236 risk assessment;
• Art. 237 technical, organisational and procedural measures; Art. 238 technical measures;
• Art. 239 information and training; Art. 240 unforeseeable exposure; Art. 241 particular work operations;
• Art. 242 health checks; Art. 243 exposure register and health records; Art. 244 registration of tumours and of adverse effects on sexual function and fertility; Art. 245 regulatory updates.

Two annexes complete the picture: Annex XLII, listing substances, mixtures and processes, and Annex XLIII, setting occupational exposure limit values. Both have been updated repeatedly, including by the Ministerial Decree of 11 February 2021 transposing Directives 2019/130 and 2019/983, which added entries such as diesel engine exhaust emissions and respirable crystalline silica dust generated by a work process. Numerical values must always be read in the current text of Annex XLIII, never in secondary sources.

The hierarchy of duties

The logic of Chapter II is strictly sequential and goes beyond that applied to ordinary chemical risk.

1. Eliminate or substitute (Art. 235). The employer must avoid or reduce use of the agent, in particular by replacing it, where technically possible, with a substance, mixture or process that is not harmful or is less harmful.
2. Assess (Art. 236). Exposure assessment must be prior, specific and documented; if it reveals the presence of the agent, the duties in Art. 237 are triggered.
3. Contain. Where technically possible, the process must run in a closed system.
4. Reduce. Where a closed system is not feasible, exposure must be reduced to the lowest technically possible level.
5. Protect collectively, then individually. Local exhaust ventilation, demarcation of risk areas, hygiene measures, and only as a last layer personal protective equipment.

The assessment must be integrated into the company risk assessment document and reviewed at every significant change in the production cycle.

Exposure register and health records (Art. 243)

This is the most frequently neglected duty and the one with the longest documentary trail.

• Workers under surveillance pursuant to Art. 242 are entered in a register recording the activity carried out, the agent or substance used and, where known, the exposure value.
• The register is established and updated by the employer, who maintains it through the occupational physician. The head of the prevention and protection service and the worker safety representatives have a right of access.
• The occupational physician establishes and updates an individual health and risk record for each worker.
• A copy of the register must be sent to INAIL and to the territorially competent supervisory body, with changes notified every three years and whenever requested.
• When employment ends, the health record and individual entries are sent to INAIL through the occupational physician, with a copy to the worker. If the company ceases activity, register and records go to INAIL.
• INAIL keeps the documentation for up to forty years after the end of any activity exposing to carcinogens or mutagens, and for at least five years for reprotoxic substances.

Templates and record-keeping arrangements remain those of Ministerial Decree 155 of 12 July 2007.

Health surveillance and training

Health checks (Art. 242) are entrusted to the occupational physician, working in close alignment with the risk assessment. This is a case where the role of health surveillance and the occupational physician cannot be reduced to a formal step: the long latency of cancer makes exposure traceability the only long-term protective instrument.

Art. 239 requires specific information and training on risks, precautions, hygiene measures, use of PPE and emergency procedures. Because these hazards are invisible and their effects deferred by years or decades, conventional training struggles to build awareness. Scenario-based formats, such as a serious game on chemical risk, help make visible a causal chain that direct experience never delivers.

Three recurring mistakes

• Stopping at the safety data sheet. Some Annex XLII entries concern processes, not substances: respirable crystalline silica dust and diesel exhaust emissions do not arrive with a label.
• Forgetting reprotoxic substances. After Legislative Decree 135/2024 many organisations must redefine the perimeter of exposed workers, particularly in healthcare and medicinal product preparation.
• Treating the register as paperwork. A register that is not updated or not transmitted defeats the protection it is supposed to guarantee forty years later.