Controlling DEEE in the workplace

What does DEEE stand for?

Diesel Engine Exhaust Emissions, often abbreviated as DEEE, represent the cocktail of harmful pollutants released by diesel engines during the combustion process. It refers to the mix of harmful gases, liquids and particles that come out of a diesel engine when it burns fuel. This includes soot, smoke, and various chemicals.

Exposure to DEEEs can be risky, especially for people who work around diesel engines frequently. It’s important for workers and employers to know the dangers of regular exposure to DEEEs to avoid accidents and health problems.

Here’s a breakdown of the main chemical constituents of DEEEs:

  • Carbon (soot)
  • Water (H20)
  • Carbon monoxide (CO)
  • Carbon Dioxide (CO2)
  • Nitrogen (N2)
  • Oxides of Nitrogen (NOx)
  • Oxides of Sulphur, eg Sulphur Dioxide (SO2)
  • Alcohols
  • Aldehydes
  • Ketones
  • Various Hydrocarbons (HC)
  • Polycyclic Aromatic Hydrocarbons (PAHs)


The makeup of DEEEs can change based on factors like the engine type, fuel, and operating conditions. However, the chemicals listed above are some of the most common and concerning constituents of DEEEs.

Most employee DEEE exposure comes from working with heavy vehicles that use diesel fuel. These vehicles will include buses, trains, trucks, tractors, and fork-lift trucks. ​

Exposure to DEEEs can cause health problems such as eye and respiratory irritation, coughing, and difficulty breathing. It can also lead to an increased risk of lung cancer because of cancer-causing substances like PAHs(Polycyclic aromatic hydrocarbons). These health issues may include producing more mucus and experiencing trouble breathing. ​

Employers must check health risks from DEEE exposure, prevent or control it, and test control measures to comply with laws. Employers must give employees information and training on health hazards and how to use control measures properly. ​

Control measures for DEEEs include engineering controls, practice, and administrative controls, and, as a last resort, respiratory protective equipment (RPE).

Controlling exposure to DEEE in specific situations


Garages and testing stations


  • Best way to reduce exhaust is by using hoses or filters attached to tailpipes to remove emissions at the source. Ensure these methods don’t interfere with visual assessments like MOT smoke checks.
  • To ventilate your small garage, open the doors or windows before starting the car. They should then remain open with the engine is running.
  • Start smart: Only start engines within the work area when essential, not for routine warm-up.
  • Natural ventilation limitations: For repairs, MOTs, or many vehicles, natural ventilation might be insufficient.
  • Multiple vehicles: Consider a network of hoses for simultaneous servicing of multiple vehicles, venting fumes outdoors.
  • Smaller garages: Open doors and windows before starting engines and keep them open during work. Utilise rear doors for additional air circulation if available. In colder weather, consider alternative control methods as open doors/windows for ventilation can trap fumes.


Bus garages


  • In bus garages, fitters who spend a full working shift are likely to be more exposed to DEEEs than bus drivers or conductors. ​ Garage doors should always remain open during the working shift to provide a steady flow of clean air. ​
  • Mechanics at Risk: Due to long shifts, mechanics face higher exposure to diesel fumes (DEEEs) from repairs and bus movements than drivers.
  • Minimise Idling: Reduce engine idling during “run-out” and “run-in” to cut garage fumes.
  • Ventilation: Separate workshops with open doors/vents are ideal.
  • Open garage doors where possible. If closed, ensure adequate fresh air replaces extracted air.
  • In-garage workshops: Use hoses or filters to control fumes directly at bus tailpipes.




  • In warehouses, reduce exposure to diesel engine exhaust emissions (DEEEs) by keeping doors open. Install extraction systems on roofs or walls to circulate air and reduce diesel fumes from forklift trucks. ​
  • Forklifts: Consider electric or propane models to reduce harmful fumes.
  • Ventilation: Open warehouse doors and install roof/wall extractors for fresh air.
  • Forklift Maintenance: Regular servicing improves engine performance and cuts emissions. Run engines only when needed.
  • Delivery Vehicles: Turn off engines during loading/unloading unless needed for hydraulics. If running is essential, use an extraction system or filter on the tailpipe.


Railways, railway repairs, and rail tunnels


  • Diesel trains release harmful fumes at stations, repair shops, and tunnels. Here’s how to reduce exposure for workers:
  • Stations: Minimise engine idling and maintain locomotives well. Natural ventilation usually works, but some stations might need special extraction systems.
  • Repair Shops: Proper ventilation like roof fans and wall ducts are key when engines are running during repairs.
  • Tunnels: Keep generators downwind and use extractor fans on trains or at tunnel entrances for short tunnels. Ideally, position locomotives and generators outside long tunnels.


Toll booths and car parks


  • In toll booths and car parks, workers can be exposed to diesel and petrol engine exhaust emissions. You should site booths in areas with good natural ventilation and easy vehicular access. ​
  • Toll booth workers will regularly breathe in car fumes. Here’s how to protect them:
  • Put booths in well-ventilated areas with easy car access.
  • Keep booth openings small to block as many fumes as possible. Open windows during slow times.
  • For high-traffic areas, use air pressure systems to pump in clean air.


Ro-ro ferries


  • Ferry workers breathe in diesel fumes while loading and unloading vehicles. Here’s how to protect them:
  • Open doors and hatches whenever possible for natural ventilation.
  • Use exhaust fans at the back of decks if the area is completely closed.
  • Install side fans for air circulation on vehicle decks with fresh air inlets.
  • Instruct truck drivers not to start engines until they’re ready to move.


Fire stations


  • Open doors before starting engines to avoid letting DEEE fumes from building up inside.
  • Minimise idling: Only idle engines when necessary and use exhaust removal systems like hoses or filters. These can be automatic to disconnect as trucks move.
  • Regular maintenance: Keep engines in top shape to reduce emissions.


  • Our solution

At Rockall Safety, we can offer employers a range of equipment to get employees through the day safely.

To see our gas detection options – click here

To see our respiratory protection options – click here


Written by Emma Curthoys

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