In the petroleum industry, chemicals classified as carcinogenic are used for tasks involved in drilling and wells, maintenance, processing and production.

Carcinogenic compounds can also be released through work operations and processes at both offshore and onshore facilities. Such carcinogenic compounds include asbestos, benzene, diesel exhaust, cooking fumes, formaldehyde, silica and welding smoke.

Risk management requirements

The employer must survey and assess risks associated with the use of carcinogenic chemicals and with the performance of work tasks that may result in the production of carcinogenic compounds. Based on the risk assessment, appropriate measures must be taken to remove or reduce exposure.

Experiences from audits show that the companies address carcinogenic chemical risk factors in different ways.

Change in limit values

In Norway, national limit values have been established for most chemical substances classified as carcinogens. Limit values are statutory maximum values for average concentrations of chemical substances in the breathing zone of a worker for a specified reference period. The limit values are used as the basis for risk assessment of exposure to chemical substances.

The limit values are amended on the basis of new knowledge about the health risks of exposure to various chemical substances. In 2021, the national limit value for benzene was reduced by 80 per cent, and a further 50 per cent reduction is expected over the next few years. 

A new limit value for diesel exhaust, measured as elemental carbon, will come into effect for petroleum operations from 21 February 2023.


As part of our supervisory activities, we have recently sent out a letter to the entire industry asking companies to answer a number of questions about their systems for managing exposure risk in this area.

Its purpose is to gain an overview of how risks related to carcinogenic chemicals and compounds are distributed and managed in the industry. We would like to acquire information about how the various companies have dealt with the reduction in limit values for benzene, as well as the extent to which the industry is prepared for and able to meet new limit values for diesel exhaust.

Our overarching goal is to help the industry maintain a high level of knowledge and focus on risk reduction in this area.

Occupational cancers

According to WHO, occupational cancers account for 4-20 per cent of cancer cases worldwide, while more than half of work-related deaths in Western countries are linked to cancer.

In Norway, around three per cent of cancers in men and 0.1 per cent in women are attributable to carcinogens in the workplace (Stami, 2021).