In brief
Diesel engine exhaust is a mixture containing particulates, nitrogen oxides and carbon monoxide, and is classified by the International Agency for Research on Cancer (IARC) as carcinogenic to humans (Group 1). In enclosed warehouses, diesel forklifts and trucks idling at the dock increase exposure, especially in winter when the doors are closed. The order of solutions is switching to electric equipment, engine and idling management, ventilation, and health surveillance planned by the physician.
Why are diesel exhaust fumes a separate risk heading?
A distribution warehouse in January: the dock doors are closed to keep the cold out, two diesel forklifts are moving pallets inside, and outside one of the queuing trucks has pulled up to the door with its engine running. In the afternoon, employees around the dock complain of headaches and burning eyes. Diesel exhaust fumes are an exposure that warehouses often dismiss as "stuffy air", but they need to be treated as a separate risk heading.
Diesel exhaust is not a single gas. It contains:
- Diesel particulates: Very fine soot particles; their cores are elemental carbon and they carry unburnt fuel and oil compounds on their surface. They can reach the deep regions of the lungs.
- Nitrogen oxides: Nitrogen dioxide in particular irritates the eyes and airways.
- Carbon monoxide: Colourless and odourless; it increases in poorly maintained engines and on cold starts.
- Aldehydes and other organic compounds: The source of irritating odour and burning eyes.
In 2012 the International Agency for Research on Cancer (IARC) classified diesel engine exhaust as carcinogenic to humans (Group 1). The issue is therefore not only one of comfort but of long-term health.
What does the legislation say?
Turkish legislation has no specific limit value for diesel exhaust; the subject is governed by several general provisions.
The European Union, with Directive 2019/130, brought work involving exposure to diesel engine exhaust emissions within the scope of the carcinogens directive and introduced a limit value of 0.05 mg/m³ measured as elemental carbon. This value has applied generally since 21 February 2023, and in underground mining and tunnel construction since 21 February 2026. It is not binding in Türkiye, but it is a good reference point when interpreting a measurement result.
Diesel forklifts indoors: situations that increase exposure
Using diesel forklifts indoors is not prohibited in itself; what matters is whether there is enough air. In site observations, mark the following situations separately:
- Winter and closed doors: In warehouses that rely on natural ventilation, air exchange drops sharply when the doors are closed.
- Entering trailers and containers: When a forklift drives into a truck trailer or container to load, exhaust collects in a narrow, enclosed volume; an employee stacking by hand inside receives the highest dose.
- Engines running at the dock: A truck pulling up to the dock door and waiting with its engine running pushes exhaust directly into the building.
- Cold starts and idling: Combustion is poorer at the first start in the morning and during long idling, and black smoke increases.
- Poorly maintained engines: Black smoke is a sign of a clogged air filter or a badly adjusted injector.
- Dead-end aisles and low ceilings: Exhaust builds up between racks where there is no air flow.
Symptoms of exhaust gas exposure and health surveillance
Short-term high exhaust gas exposure can cause burning in the eyes, nose and throat, coughing, headache, dizziness and nausea. If symptoms ease at the end of the shift or on going outdoors, the link to the environment is strong. If headache, light-headedness and nausea occur together, carbon monoxide poisoning should also be considered; we described the symptoms and first response in our article on carbon monoxide poisoning.
In the long term, respiratory complaints and lung cancer risk come to the fore. The health surveillance plan therefore takes the following into account:
- The frequency of periodic examinations is set by hazard class: at least every 5 years in less hazardous, at least every 3 years in hazardous and every year in very hazardous workplaces. The workplace physician may shorten this interval.
- Tests such as lung function tests and chest X-rays have no fixed frequency in the legislation; the physician decides according to the level of exposure and individual risk.
- Employees with asthma or chronic lung disease are assessed separately for tasks with heavy exhaust exposure.
- Smoking increases lung risk together with exhaust; health surveillance consultations are also an opportunity to support quitting.
We plan tests with authorised healthcare providers; the aggregate assessment of the results feeds back into the risk assessment.
Measurement: what to measure and how
No single parameter describes exhaust exposure. Build the measurement plan around this table:
| Parameter | What does it show? | Practical note |
|---|---|---|
| Elemental carbon | The most specific indicator of diesel particulate exposure | Taken by personal sampling over the shift; the EU limit value can be used as a reference |
| Nitrogen dioxide | Irritant gas load | Checked separately at heavy points such as the dock and inside trailers |
| Carbon monoxide | Combustion quality and acute poisoning risk | Can be monitored continuously with fixed or personal detectors |
| Air exchange | Adequacy of ventilation | Mechanical system flow rate is compared with conditions when doors are closed |
We plan measurements with authorised laboratories; the laboratory's ISG-KATİP (the Ministry's online OHS registration system) notification and accreditation certificate are checked. The result should be interpreted noting whether the doors were open or closed on the day of measurement and how many vehicles were running; a measurement taken in summer with the doors open does not represent winter conditions. For measurement types, see our article on workplace chemical exposure measurement.
Garage ventilation and switching to electric equipment
Rank the measures according to the hierarchy of controls; personal protective equipment is the last link.
- Switching to electric equipment: In enclosed warehouses, the most lasting solution is to use battery-powered forklifts and stackers instead of diesel forklifts. New risks arise with the switch: the battery charging area, hydrogen from lead-acid batteries, fire with lithium batteries. Set up the charging area according to the principles in our article on lithium battery charging area safety.
- LPG forklifts: They cause fewer particulate problems but produce carbon monoxide; they are not a complete solution, and engine tuning is still critical.
- Engine and idling management: Set an "engine off while waiting" rule at the dock and announce it with signs. Follow the manufacturer's maintenance schedule for diesel equipment and, if there is a diesel particulate filter, track its cleaning and regeneration.
- Work organisation: Reduce forklift entries into trailers and containers; if hand stacking is needed inside, the forklift should wait outside.
- Garage ventilation: In vehicle maintenance garages, use an extraction hose fitted to the exhaust pipe; do not run engine tests in a closed garage without the hose. If the warehouse has mechanical ventilation, verify by measurement whether it is adequate with the doors closed.
- Personal protective equipment: A particulate filter mask captures some of the particulates but does not protect against nitrogen oxides and carbon monoxide. Do not present the mask as a permanent solution.
Our articles on loading dock safety for dock layout and door management, and on the warehouse forklift and pedestrian traffic plan for forklift traffic, are complementary. In logistics and warehousing businesses, including Gemlik with its warehouses around the port and free zone, we deal with exhaust exposure as a separate row in the risk assessment document.
Frequently Asked Questions
Is it prohibited to use a diesel forklift in an enclosed warehouse?
There is no direct prohibition. The Regulation on Work Equipment allows mobile equipment with an internal combustion engine to be used only if sufficient air is provided so that it does not create a risk for employees. You need to be able to show through ventilation and measurement that this condition is met.
Does a dust mask protect against diesel exhaust?
Partly. A particulate filter mask captures part of the diesel particulates; it does not protect against gases such as nitrogen dioxide and carbon monoxide. A mask does not replace reduction at source and ventilation.
Is there a limit value for diesel exhaust in Türkiye?
No. Diesel exhaust does not appear in the list or the limit value table of the Carcinogens Regulation. When interpreting a measurement result, the EU value of 0.05 mg/m³ for elemental carbon can be used as a reference.
Is fitting a diesel particulate filter enough?
It reduces the particulate load but does not by itself solve nitrogen oxides and carbon monoxide; if filter maintenance lapses, its effect drops. In enclosed warehouses, the lasting solution is switching to electric equipment and adequate ventilation.
An exposure-based test plan, pre-employment and periodic examinations, confidential health files and an examination schedule tracked per person.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.