Carcinogens and mutagens

What are carcinogens and mutagens?

Carcinogens are substances, compounds and mixtures which, if they are inhaled or ingested or if they penetrate the skin, may cause malignant tumours or increase their prevalence.

Carcinogenic chemicals fall into two categories:

• Category I, which in turn is divided into subcategories IA (proven carcinogenic effect to humans) and IB (proven carcinogenic effect to animals).
• The signal word for carcinogens IA and IB is ‘caution’ and the risk phrase H350 is ‘may cause cancer’ (it is necessary to state the route of exposure if it is conclusively proven that no other routes of exposure cause the hazard).
• Category II – potential carcinogenic effect. The signal word is ‘caution’ and the risk phrase H351 is ‘likely to cause cancer’ (state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard).

Mutagens are substances and preparations which, if they are inhaled or ingested or if they penetrate the skin, may cause genetic alterations or increase their prevalence.

Mutagenic chemicals fall into two categories:

• Category I, which is similarly divided into subcategories IA (evidence of mutagenicity in humans) and IB (evidence of mutagenicity in animals).
• The signal word for mutagens IA and IB is ‘caution’ and the risk phrase H340 is ‘may cause genetic defects’ (it is necessary to state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard).
• Category II – the signal word is ‘caution’ and the risk phrase H341 is ‘likely to cause genetic defects’ (state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard).

In general, the requirements for handling carcinogens and mutagens are similar to those for using any hazardous chemical. However, it should be noted that exposure to this group of chemicals is always dangerous, which means that there is no safe level and that a weakening of the body's defences can lead to cancer or a genetic defect.

Handling of carcinogens and mutagens

The handling of carcinogens and mutagens in the working environment is regulated by Government of the Republic Regulation No. 308 of 15 December 2005 ‘Occupational health and safety requirements for the handling of carcinogenic and mutagenic chemicals’.

The requirements of the regulation must be met:

• if the chemical used in the work is classified as carcinogenic or mutagenic category 1A or 1B;
• in production of auramine (CAS 492-80-8);
• work processes where an employee may be exposed to polycyclic aromatic hydrocarbons contained in coal soot, tar or pitch;
• soldering, welding or other heat treatment of materials containing copper and nickel where dust, smoke or aerosol of these metals is produced;
• strongly acidic processes of isopropyl alcohol production;
• in work processes where the worker may be exposed to dust from the processing of hardwood timber, such as beech or oak;
• work processes where the worker may be exposed to inhalable crystalline silica dust;
• work processes during which the worker's skin may come into contact with mineral oils that have previously been used to lubricate and cool the moving parts in internal combustion engines;
• work processes during which the employee may come into contact with exhaust gases from diesel engines;
• in other work processes where there is a risk of workers being exposed to carcinogens or mutagens;
• with the specifications arising from the Radiation Act at the work of radiation workers;
• asbestos work, without prejudice to the stricter or more specific provisions established by Government of the Republic Regulation No. 224 of 11 October 2007 ‘Occupational Health and Safety Requirements for Asbestos Work’.

Information on the possible carcinogenicity of a hazardous chemical can be found in the chemical safety data sheet.

For example, section 2 of the Safety Data Sheet for unleaded petrol states: Carc. 1B, H350. May cause cancer. The label indicates that it is a carcinogenic chemical.

Section 8 of the Safety Data Sheet for unleaded petrol states:

• Respiratory protection equipment is not required in case of low use, small amounts, short-term exposure (up to ten minutes). In the case of moderate use, moderate amounts, moderate exposure (exceeding one hour) and insufficient ventilation: Wear respiratory protection with type A2 gas filter. Respiratory protection must meet the following standards: EN 136/140/145.
• Wear Viton rubber or nitrile gloves to protect your hands.
• Wear tight-fitting safety goggles (EN 166) if splashes are likely to occur.
• Use protective clothing for prolonged work with the product.

The employer must provide all workers who come into contact with petrol, for example when refuelling, with nitrile or Viton rubber gloves. Normal refuelling does not require the use of protective clothing or respiratory protection, as refuelling last a few minutes and takes place outdoors (in the fresh air). However, if you are exposed to petrol for a long time (for example in a car repair shop) and in poorly ventilated rooms, you must also use respiratory protection and, as a general rule, tight-fitting safety goggles.

No matter how much the worker is exposed to the risk factor (for example, five minutes a week), the employer must identify and assess the risk to the worker's health and safety during the risk assessment. The time of exposure must be taken into account when assessing health risks, as the risk varies for a worker who refuels for five minutes a week (or a month) or is exposed to petrol for most of their working time (e.g. a car-repair locksmith). The assessment must also take into account the use of personal protective equipment and the conditions under which petrol is used (outdoors or in an unventilated room). If all the circumstances are taken into account, an ordinary worker who is exposed to a carcinogenic chemical at work for five minutes a week and outdoors while using suitable gloves is not endangered.

The employer must issue the required personal protective equipment to the employees and introduce the employee to the chemical safety data sheet, drawing the employee's attention to the fact that it is a carcinogenic chemical.

Risk assessment

For all work processes where workers are subject to the hazard of being exposed to carcinogens or mutagens, the employer must determine the nature, extent and duration of the exposure in the work environment risk assessment and consequently assess the risk to workers' health and safety and take the necessary preventive measures.

The risk assessment must take into account all routes of exposure to carcinogens or mutagens, including absorption into the skin or through the skin into the body.

The employer must pay particular attention to the participation of vulnerable workers, such as pregnant and breastfeeding women and minors, in the work process and take into account legal restrictions to ensure their safety.

For example, minors are prohibited from working with carcinogenic chemicals pursuant to Government of the Republic Regulation No. 94 of 11 June 2009 ‘List of occupational hazards and work prohibited to minors’; according to subsection 2 (13) of the regulation, minors are prohibited from working with chemicals classified as carcinogenic, category 1A, 1B or 2 (H350, H350i, H351), and according to subsection (14) of the regulation, prohibited from working with chemicals classified as mutagenic, category 1A, 1B or 2 (H340, H341);

According to § 6(2) of the Republic of Estonia Government Regulation No. 95 of 11.06.2009, "Occupational health and safety requirements for pregnant and breastfeeding women", the employer is required to consider the following chemical substances when assessing health risks for female employees:

• Chemicals classified as carcinogenic, category 1A, 1B, or 2 (H350, H350i, H351);
• Germ cell mutagenicity, category 1A, 1B, or 2 (H340, H341);
• Carcinogenicity, category 1A, 1B, or 2 (H350, H350i, H351);
• Reproductive toxicity, category 1A, 1B, or 2, or an additional category for effects on or through lactation (H360, H360D, H360FD, H360Fd, H360Df, H361, H361d, H361fd, H362);
• Target organ toxicity – single exposure, category 1 or 2 (H370, H371).

Where the results of the risk assessment in the working environment indicate that carcinogens or mutagens may endanger the health of workers, workers' exposure to these substances must be avoided as far as possible by restricting their use, replacing them with safer chemicals or using safer technology.

The employer must ensure that access to areas involving a health risk is granted only to those workers whose work or duties require it.

If it is not technically possible to replace carcinogens or mutagens with safer chemicals or to use safer technology, the employer must ensure, as far as technically possible, that they are handled in a closed system. Where the use of a closed system is not technically possible, the employer must ensure that workers' exposure to carcinogens or mutagens is minimised and that the risk posed by the chemical does not exceed the prescribed working environment exposure limit value.

Measures to reduce health risks:

• limiting the amount of carcinogen or mutagen stored or handled in the working environment to the minimum necessary;
• reducing the number of workers exposed to carcinogens or mutagens to a minimum;
• designing the work process in such a way that the release of the carcinogen or mutagen into the working environment is prevented or, if prevention is not possible, minimised by the implementation of control measures;
• removal of the carcinogen or mutagen at source by means of local extraction, general ventilation or other appropriate measures;
• the use of monitoring methods for the timely detection of the release of a carcinogen or mutagen;
• implementation of safe working practices and methods, including the use of collective or personal protective equipment;
• implementation of appropriate hygiene measures, including regular cleaning of floors, walls and other surfaces;
• timely and accurate informing of employees;
• demarcation of risk areas and the use of appropriate safety signs, including the prohibition sign "No smoking" in areas where workers are or may be exposed to a carcinogen or mutagen;
• drawing up an action plan in the event of an accident in which workers may be exposed to large quantities of carcinogens or mutagens;
• storage of handled chemicals in hermetically sealed, clearly and visibly labelled containers;
• collection of hazardous industrial waste in hermetically sealed and clearly labelled containers;
• implementation of safe means of storage, transport and disposal.

Occupational hygiene measures to reduce exposure to carcinogens:

• banning eating, drinking and smoking in areas where there is a risk of contamination with carcinogens and mutagens;
• providing employees with appropriate work clothing and, where necessary, with protective clothing and respiratory protection;
• creating separate storage facilities for work and personal clothing;
• providing employees with washrooms equipped with showers and, if necessary, installing eyewash stations;
• cleaning, inspecting and storing used personal protective equipment at a specified location after the end of the working day;
• regular cleaning and washing of work and protective clothing and, in case they become unusable, their handling in accordance with the Waste Act

Unforeseen exposure

Where a significant increase in workers' exposure to carcinogens or mutagens can be expected during some work processes, such as equipment maintenance, and where normal technical measures to protect workers are not sufficient, the employer shall, after consulting workers or their representatives, determine the specific measures necessary to ensure their health and safety.

In this case, workers must be provided with protective clothing and personal respiratory protective equipment which they must wear for as long as the exposure to carcinogens or mutagens persists, the exposure being limited to the minimum necessary for each worker. The area where the work is to be carried out must be clearly marked and access by unauthorised persons must be prevented.

Training of employees

As with any job, the employer must provide instruction and training to workers on exposure to carcinogens and mutagens. There must be written safety instructions for carrying out the instruction, which must be available to the employees. The instructions must be prominently displayed so that the worker can quickly refresh their memory during work if necessary.

The training must cover the following topics:

• adverse health effects of carcinogens and mutagens, including the increased risk of damage to health in case of smoking;
• safety measures to avoid exposure to carcinogens and mutagens;
• the meanings of the safety signs used;
• occupational hygiene requirements established in the company;
• the purpose and procedure for the use of personal protective equipment, including protective clothing;
• instructions for action in the event of a dangerous situation.

The training must be repeated if there are significant changes in the work process concerning the carcinogens or mutagens, or the equipment or technology used.

The employer shall inform workers of the equipment and containers containing carcinogens or mutagens used in the establishment and shall ensure that all equipment, containers and packaging containing these substances bear clearly legible labelling and clearly visible warning signs.

The employer must keep a list of workers exposed to carcinogens as a result of their work, which must include the following information:

• first name and surname of the employee;
• description of duties;
• the name of the carcinogen or mutagen to which the worker has been exposed;
• duration of exposure to the carcinogen or mutagen.

Data on a listed worker must be kept up-to-date by the employer for at least 40 years after the worker was last exposed to the carcinogen. The employee has the right to know the data about them entered into the list. Employees and the working environment representative must have access to non-personalised statistical information on the list.

The list of employees must be available for inspection by an occupational health doctor, a working environment specialist and a labour inspector.

Medical examination of employees

Further reading

• Acrylamide
• Asbestos
• Benzene
• Beryllium
• Cadmium
• Chromium VI
• Diesel engine exhaust
• Ethylene oxide
• Formaldehyde
• Hardwood dust
• Hydrazine
• Lead
• Nickel
• Polycyclic aromatic hydrocarbons (PAHs)
• Silica dust
• Trichloerethylene
• Welding fumes
• Vinyl chloride