Diesel Engine Exhaust Emissions (DEEEs)


Diesel engine exhaust emissions (DEEEs) have been hitting the headlines because of their impact on air quality, but trade unions point out they are also a major cause of occupational ill health and have described exposure to diesel fumes as a “ticking time bomb”. 


The HSE explains that DEEEs are a mixture of gases, vapours, liquid aerosols and particulate substances. They contain products of combustion including carbon (or soot), nitrogen, water, carbon monoxide, aldehydes, oxides of nitrogen, oxides of sulphur and polycyclic aromatic hydrocarbons. 


In the short term, breathing in high quantities of diesel fumes can irritate the eyes and chest, while the long-term effects include chronic respiratory ill health. In 2012, the International Agency for Research on Cancer (IARC), part of the World Health Organisation, classified DEEEs as carcinogenic to humans (Group 1), based on sufficient evidence that exposure is associated with an increased risk for lung cancer. It also reported a “positive association” with an increased risk of bladder cancer. 


The GMB identifies workplaces where exposure to diesel fumes is most likely as garages and testing centres, bus garages, warehouses, roll-on, roll-off ferries, railways, rail repairs and tunnels, toll booths and car parks, internal enclosed roadways and fire stations. The general union Unite points to bus, car and lorry maintenance engineers, bus, lorry and tractor drivers, fork lift truck drivers and other warehouse workers, miners and construction workers as just some of the examples of those who are exposed to diesel fumes in the course of their work.


Diesel fumes are covered by the 2002 COSHH regulations and employers have a legal duty to make a suitable and sufficient assessment of the risk of people being exposed to DEEEs and to prevent or reduce exposure by putting into place suitable control measures. But unions say the law and its enforcement need to be strengthened.


There is currently no WEL set for DEEEs. The HSE says that: “No WEL has been set for DEEEs as a whole because there is insufficient data to establish a clear, reliable threshold for all potential health effects. Furthermore, there is no ideal candidate marker of exposure to DEEEs on which to base a WEL.”


It goes on to explain that several of the major gaseous components of diesel exhaust have WELs and that while the particulate material itself has no set WEL, there are “values which in themselves act as triggers for the application of the regulations, that is, 10 mg/m3 8-hour TWA total inhalable dust or 4 mg/m3 8-hour TWA respirable dust.” It advises employers that controls are likely to be adequate if there is:


• no visible haze in the workplace;


• no visible soot deposits;


• no complaints of irritancy;


• carbon dioxide levels much lower than 1000ppm (eight-hour time weighted average — TWA); and 


• the time workers spend around idling engines is minimised.


Rail union RMT has started a campaign for a WEL for diesel as a whole product (see page 98), and the European Trade Union Institute (ETUI) has criticised the failure of the European Commission to extend the scope of the carcinogens and mutagens directive to include DEEEs or add them to the list of limit values (see pages 100-101).


The general union Unite says it has gathered evidence suggesting that many employers are flouting the COSHH regulations when it comes to diesel fume exposure, and the TUC has called for greater enforcement in relation to exposure to DEEEs as one of five key demands to reduce work-related cancer. 


Unite has launched a diesel-emissions register so that its members can record when they have been exposed to excessive diesel fumes. The union says it will use this information to report accidents and “force employers to clean up their workplaces” and form the basis of future legal claims. 


The union-backed Greener Jobs Alliance (GJA) has also developed online and face-to-face training courses (which it is running with the Hazards campaign) on air quality to help trade unionists take action on air pollution. More information can be found on its website at: www.greenerjobsalliance.co.uk.