Emissions from diesel engine exhaust can affect the health of a wide variety of workers, from bin men to bus drivers and builders to mechanics. In the following article, Vicky Powell examines the management of diesel exhaust fumes in the workplace in the context of their reclassification as a definite cause of cancer by international health experts, and the growing attention they are receiving from both the authorities and leaders in the health and safety profession.

Recent changes

Those who follow the major issues in health and safety will have noticed a number of important recent changes with regard to the treatment of diesel engine exhaust emissions (DEEE) in the workplace. In 2012, the International Agency for Research on Cancer, part of the World Health Organization, reclassified DEEE from “probable carcinogens”, upgrading them to a Group 1 carcinogen, and therefore formally recognising them as a definite cause of cancer in humans. The IARC also said that people regularly exposed to diesel exhaust fumes at work can be up to 40% more likely to develop lung cancer.

Subsequently, in November 2014, diesel exhaust fumes were identified as one of five important risk factors for occupational cancer by the Institution of Occupational Safety and Health (IOSH) in its No Time to Lose campaign, which is designed to highlight and raise awareness of work-related cancer. (The other four important risk factors under the spotlight in the campaign are solar radiation, asbestos, silica dust and shift work.)

Then, in April 2015, the British Occupational Hygiene Society (BOHS) launched its new Breathe Freely initiative, aimed at controlling exposures to prevent occupational lung disease in the construction industry. Again, diesel exhaust fumes were emphasised by the Chartered Society for Worker Health Protection as one of the key hazards to which construction workers could be exposed, at the risk of harm to their respiratory health.

Finally, in the regulatory context, the new Workplace Health Expert Committee (WHEC), recently put together by the Health and Safety Executive (HSE), has formally prioritised DEEE as its first issue on its future programme of work.

Understanding DEEE

As part of its No Time to Lose campaign, IOSH recently produced new guidance entitled Diesel Exhaust Emission Fumes: The Facts. The guidance defines diesel engine exhaust fumes as “a mixture of gases, vapours, liquid aerosols and particles created by burning diesel fuels,” warning that diesel fumes may contain over 10 times the amount of soot (carbon) particles than in petrol exhaust fumes, and that the mixture includes several carcinogenic substances.

As part of its No Time to Lose campaign, IOSH recently produced new guidance entitled Diesel Exhaust Emission Fumes: The Facts. The guidance defines diesel engine exhaust fumes as “a mixture of gases, vapours, liquid aerosols and particles created by burning diesel fuels,” warning that diesel fumes may contain over 10 times the amount of soot (carbon) particles than in petrol exhaust fumes, and that the mixture includes several carcinogenic substances.

The HSE’s guidance INDG286: Diesel Engine Exhaust Emissions points out that the colour of fumes are important. Blue smoke can indicate a poorly serviced engine, whilst black smoke indicates soot and a mechanical problem. In its guidance, IOSH warns that both blue or black smoke could mean that more toxic fumes are being produced. In contrast, white smoke is usually produced when the engine is started from cold and disappears when the engine warms up, according to the HSE guidance.

Diesel — half a million workers at risk in the UK?

Asked for comment on this article, Phil Bates, a Chartered Member of IOSH, said, “DEEE is one of the main causes of workplace cancers that contribute to occupational exposure being the fifth most avoidable cause of cancer in the UK.”

He added, “DEEE affect many industries — not just transport but agriculture, construction, energy extraction, warehousing and mechanics. The HSE estimates that 100,000 workers in the UK could be exposed to high levels of DEEE, but others such as the Imperial College and the Institute of Occupational Medicine (IOM) put the figure at 500,000. In Europe, this could be as high as 3.6 million. Exposure to high levels of DEEE results in more than 650 deaths a year from lung and bladder cancer in Britain and 4,500 in Europe.”

Risk assessment and control measures

Despite these grim statistics, Phil Bates points out that, “There are several ways to reduce exposure, including use of more modern engines with filters, improving ventilation and switching off engines rather than idling as just some examples.”

Reducing exposure must start, as ever, with a good risk assessment and the new IOSH guidance suggests a series of practical questions to assess the risks relating to DEEE in a workplace, from the basic, “Are diesel engines or equipment being used in the workplace?” to the more technical, such as checking for soot deposits on workplace surfaces, noting whether there is a visible haze and inspecting the colour of any smoke. The guidance emphasises that workers suffering irritation of the eyes or lungs are, certainly, a sign of the risk of harm.

If exposure cannot be prevented altogether, for example by substituting diesel fuel for a safer fuel or alternative technology, the HSE suggests examples suitable control measures as including:

  • workplace air extraction fans

  • tailpipe exhaust extraction systems

  • the use of filters attached to tailpipes

  • catalytic converters.

More general control measures could include:

  • turning off engines when not required

  • keeping doors and windows open where practicable

  • installing air vents in the walls and ceiling

  • job rotation

  • providing suitable personal protective equipment (such as suitable gloves for handling hot and cold diesel fuel).

More detailed guidance on control measures for DEEE is available in the HSE guidance HSG187: Control of Diesel Engine Exhaust Emissions in the Workplace.

Best practice and case studies

The HSE has published a number of case studies which are interesting in the context of DEEE. One case study focuses on a risk assessment of the activities in a small warehouse, employing just 12 people, which identified the issue of vehicle exhaust fumes as a hazard. However, the number of vehicles delivering materials was found to be “relatively low” and exposure was therefore judged as “very limited” with any build-up of fumes being prevented. In addition, drivers were not allowed to leave vehicles’ engines running in the warehouse and the roller shutter doors and warehouse windows were kept open, where practicable, to assist ventilation. As a result, no further action was required.

In another case, a motor vehicle mechanical repair workshop employed 12 mechanics, including two apprentices who carried out mechanical repairs. Car engines were running inside the premises, with “toxic exhaust fumes” identified as a key hazard. Controls included attaching car exhausts to an extractor system when engines were running as well as testing and maintaining of the extractor system to prevent leaks. Beyond this, again, no further action was required.

In another case, a motor vehicle mechanical repair workshop employed 12 mechanics, including two apprentices who carried out mechanical repairs. Car engines were running inside the premises, with “toxic exhaust fumes” identified as a key hazard. Controls included attaching car exhausts to an extractor system when engines were running as well as testing and maintaining of the extractor system to prevent leaks. Beyond this, again, no further action was required.

In managing DEEE, the IOSH guidance warns, “A little knowledge can be a dangerous thing”. Competency is key with regard to DEEE — assessing, managing and monitoring exposure to harmful substances are specialist areas. Therefore, calling on expert advice, such as through BOHS or the Occupational Safety and Health Consultants Register to find the right expertise is important, where necessary.

Diesel is a common substance in the workplace and the challenge is to ensure that the very familiarity of diesel does not breed contempt, so that emissions associated with diesel are treated, and controlled, with the respect they require.

Last reviewed 17 August 2015