Diesel fumes - assessing the risk

Date published




The Institute of Occupational Safety and Health (IOSH) has reported that the term “occupational cancer” is used to describe all cancers contracted, following exposure to a cancer-causing agent (carcinogen) at work. Some carcinogens are widely publicised, for example asbestos, while others may be less obvious, such as diesel fumes.

The Health and Safety Executive (HSE) estimates that more than 100,000 workers could be exposed to high levels of diesel engine exhaust fumes. Notably, Imperial College London and the International Organization for Migration estimate that it is closer to 500,000.

Approximately 800 new cases of cancer linked to diesel exhaust fume exposure are registered each year.

If you are an employer, you will need to consider the level of exposure to your employees and the associated risk.


Diesel engine exhaust emissions are a mixture of:

  • Gases
  • Vapours
  • Liquid aerosols
  • Substances

… made up of particles created by burning diesel fumes.

Breathing in high quantities of diesel exhaust fumes can cause irritation in the respiratory tract within a few minutes of exposure. Prolonged exposure over many years may be more harmful.

Anyone working with or around diesel-powered equipment or vehicles can be affected. This can lead to lung and bladder cancer.

The long-term exposure to the ‘particulates’ or soot are where the problems arise. The soot is the black smoke that is emitted from the exhaust. The amount of soot depends upon the quality of the diesel and the cleanliness of the vehicle or plant.

Most modern day vehicles have particulate filters, but that has not always been the case. When one considers plant and machinery such as generators, compressors and construction vehicles — such as excavators and dumper trucks — the technology involved was basic in order to aid maintenance and reliability. Those workers regularly exposed to such plants and machinery are most at risk.

Although individuals are more likely to be diagnosed with a cancer caused by long-term exposure to diesel exhaust fumes later in life, many will suffer respiratory symptoms at a much younger age.


The IOSH and HSE have issued warnings as diesel fumes has now been reclassified as a Grade 1 carcinogen, meaning it is are a definite cause of cancer.

The warning issued applies to a huge range of employees. It could include highway workers, community transport drivers, refuse collectors, front line driver-led services such as carers/meals on wheels, mechanics and housing/construction workers.

We recommend asking the following questions:

  • Is this an area in which you formally assess the hazard?
  • What prevention and control measures do you have in place?
  • Do you regularly subject your workers to health surveillance?

Operations should be properly risk-assessed to consider exposure. Vehicle repair workshops should have appropriate filtration and ventilation systems. Plant and machinery should have compliant filtration systems built in and — where risks still remain due to third party activities — respiratory equipment should be considered.

Those who work closely to or behind diesel vehicles — such as refuse and recycling operatives — should consider the use of gas and electric vehicles.


If, as an employer, new cases of exposure to diesel fumes are identified, the employee’s lifestyle should be investigated, for example:

  • Has the individual smoked in the past?
  • Did they spend a considerable amount of time in smoke-filled environments whether socially or at home with other family members who were or are smokers?

By far the greatest cause of lung cancer is caused by smoking, whether an actual smoker of passively.

Matters should be investigated at this stage by way of regular health screening and updated risk assessments, looking specifically at exposure and identifying the possible exposure risks.

Read other items in the Personal Injury Brief - September 2017