Which work processes involve a risk of occupational cancer?
Certain work processes, including activities or working conditions, can cause cancer. How can their carcinogenicity be identified in order to better protect exposed workers? ANSES has developed a method for identifying carcinogenic processes, and used it to assess the carcinogenicity of three of them. It also drew up a priority list of processes needing expert appraisal over the coming years.
A method for identifying new carcinogenic processes in order to include them in the regulations
While the regulatory classification of carcinogenic chemical substances and products is based on criteria defined by the European Regulation on Classification, Labelling and Packaging (the CLP Regulation), this is not the case for processes and circumstances of exposure that can cause cancer in workers.
Examples of these processes and circumstances include welding or sanding operations that can expose workers to a range of harmful gases, particles and dust, and specific working conditions such as outdoor activities exposing workers to the sun's UV rays, or night work.
In the absence of established scientific criteria at European and French level, the French Directorate General for Labour asked ANSES to examine the inclusion of new carcinogenic processes in the regulations from a scientific perspective. The Agency therefore carried out several expert appraisals between 2021 and 2024.
What is considered to be a work process?
For the purposes of classification as a "carcinogenic process", ANSES considers not only industrial processes, but also the ways in which work is organised, occupations, occupational tasks and, more broadly, all situations involving occupational exposure to groups of chemical, physical or biological agents. On the other hand, it excludes relational (interpersonal) constraints, and therefore factors that could generate psychosocial risks.
The list of carcinogenic processes according to the regulations applicable in the workplace is given at European level in Annex I of Directive 2004/37/EC and at French level in the Ministerial Order of 26 October 2020. At present, the list in this Order essentially comes from transposing European directives.
When a process is included as a carcinogen in the regulations applicable in the workplace, strengthened assessment, information and prevention measures must be put in place, including individual medical monitoring. Employers must also substitute carcinogenic processes for other ones whenever possible.
The Agency has drawn up and published a methodology for identifying and assessing carcinogenic processes, based on the results of existing international work, including the assessments of the International Agency for Research on Cancer (IARC), the work of the Dutch Expert Committee on Occupational Safety (DECOS) and the US National Toxicology Program (NTP). The aim of this methodology is to determine which organs are affected by cancer and ascertain the level of evidence, i.e. the degree of certainty surrounding the causal link between exposure while carrying out the process in question and the onset of cancer.
A methodology already applied to three processes
In recent years, at the request of the Ministry of Labour, ANSES used this methodology to assess three processes that are strongly suspected of being carcinogenic and also widely encountered in the workplace:
- work involving exposure to cytotoxic drugs, which led ANSES in 2021 to recommend that work involving exposure to 18 active substances in cancer drugs be included in the French regulations;
- work involving exposure to welding fumes, which, in 2022, the Agency recommended should also be included in the regulations. This concerns work involving exposure to welding fumes or metal fumes from related processes including hard soldering, gouging, oxy-fuel cutting, thermal spraying, and hardfacing;
- work involving exposure to polycyclic aromatic hydrocarbons (PAHs), on which ANSES has just finalised an assessment specifically on work involving exposure to emissions from frying.
Recognising the carcinogenicity of work involving exposure to emissions from frying with animal or vegetable fats
During frying, the increased temperature promotes physical and biochemical transformations of the fat and food, generating emissions of PAHs, fine and ultrafine particles and numerous volatile organic compounds. The composition of frying emissions varies according to the frying type and temperature, the fat used, the cooking time, the type of food being fried and the energy source used for cooking.
In 2010, the IARC classified emissions from high-temperature frying as "probably carcinogenic to humans". The updated data obtained by ANSES support this classification as a probable human carcinogen for lung cancer. After implementing its assessment methodology, the Agency recommended adding work involving exposure to emissions from frying with animal or vegetable fats to the regulatory list of carcinogenic processes, for the following three frying methods: pan-frying, stir-frying and deep-frying (i.e. where food is completely immersed in fat).
ANSES stresses that few studies have been published outside South-East Asia, to assess either the carcinogenicity of frying emissions or occupational exposure. This raises questions about the level of awareness of occupational exposure due to this cooking method in France, and indeed in Europe, despite the many workers concerned: according to INSEE, over 1,400,000 people were employed in the catering and agri-food sectors in France at the end of 2021.
The Agency therefore recommends that studies or research be conducted to generate knowledge on the hazards, exposures and risks associated with work involving exposure to frying emissions, to enable the practices implemented in France or more widely in Europe to be taken into account.
A list of 15 other processes to be assessed
In addition to the three processes already assessed, the Agency has identified 15 others, three of which need to be examined as a priority:
- work involving exposure to solar and ultraviolet radiation, with more than 1 million workers potentially exposed;
- exposure from work as a firefighter, with between 100,000 and 1 million workers potentially exposed;
- night work, with over 1 million workers potentially exposed.
This ranking exercise, based on data available up to September 2023, was carried out using the SIRIS method (System of Integration of Risk with Interaction of Scores), which combines qualitative and quantitative criteria. Two criteria were taken into account: the number of workers in the industry sectors concerned by the processes in France, given the lack of data on the number of workers potentially exposed, and the carcinogenic classification of the process in question.