Diesel engine exhaust (DEE) and diesel particulate matter (DPM)
Diesel engine exhaust (DEE) is created by burning diesel fuel. It contains a mixture of:
- gases, including hazardous chemicals like nitrous oxide, nitrogen dioxide, sulphur dioxide and carbon monoxide
- fine particles known as diesel particulate matter (DPM).
Essentially, DPM is soot – small carbon particles that other substances can stick to, including carcinogens like polycyclic aromatic hydrocarbons (PAH) from the incomplete burning of fuel, metal fragments from engine wear, sulfates and nitrates from exhaust gases, and organic carbon compounds from engine oils and lubricants.
DPM can act like a gas and stay airborne for long periods, and because the particles are so small, they penetrate deep into the lungs.
DPM health effects
In the short term, exposure to diesel exhaust can cause irritation of the eyes, nose, throat and lungs, and even suffocation.
Most seriously, diesel particulate matter is a Group 1 carcinogen. Workers exposed to DPM over the long term have a greater risk of developing lung cancer, and possibly bladder cancer; long-term exposure can also worsen allergies and increase the risk of heart and lung disease.
Around 1.2 million Australians are exposed to diesel exhaust at work every year, with around 130 diagnosed with lung cancer as a result. It’s the second most common workplace carcinogen after UV radiation. The risks are highest in enclosed, poorly ventilated areas where exhaust can build up, such as vehicle repair workshops, tunnels, partially covered roadways and walkways.
Workers most at risk of DPM exposure include:
- drive-in booth operators
- miners
- construction workers
- oil and gas workers
- airline ground workers
- forklift drivers
- loading dock workers
- truck drivers
- farm workers
- stevedores
- vehicle maintenance workers.
As the person in control of a workplace, it’s your responsibility to make it as safe as you can, and to ensure your workers aren’t exposed to excessive levels of DPM. That’s why it’s worth having an effective diesel particulate monitoring program in place, overseen by specialists.
Assessing, monitoring and controlling DPM
Assessing DPM risk
Before starting a DPM monitoring program at your workplace, Airsafe carries out an initial risk assessment. We do a walkthrough of the premises, using our experience and expertise to identify and assess the hazards from activities that generate diesel exhaust, and where we can, we consult the workers who operate diesel-powered machinery.
The risk from DPM exposure varies with a number of factors, including:
- location of the operating engine (outdoors or in an enclosed space)
- ventilation in the workspace
- number of engines
- type and age of the engine
- size of the engines
- fuel pump setting
- engine temperature
- fuel used (for example, low-sulphur diesel)
- use of emission control systems
- state of engine tuning and maintenance
- pattern of use (load and acceleration)
- how long the worker is exposed.
Because so many factors feed into the risk from DPM, it’s important to get an assessment from a company with deep experience and expertise in occupational hygiene, like Airsafe. With our holistic approach, we can also assess other hazards that come with operating diesel machinery, such as noise exposure.
Exposure standards for DPM
For a long time there was no national workplace exposure standard for diesel particulate matter in Australia – standards existed only for some individual components of diesel exhaust, such as carbon monoxide, carbon dioxide and respirable dust. That’s changing. From 1 December 2026, diesel particulate matter is included for the first time in the new national workplace exposure limits (WEL), measured as respirable elemental carbon (REC) – the core carbon component of DPM. (As part of this change, the workplace exposure standards are being renamed workplace exposure limits.)
Some jurisdictions had already acted ahead of the national limit. In the mining industry, New South Wales introduced its own exposure standard – keeping DPM below 0.1 mg/m3 as an eight-hour time-weighted average, measured as sub-micron elemental carbon – which came into force in 2021 and still applies to mines and petroleum sites. And in the absence of a national figure, many occupational hygienists, Airsafe among them, used the Australian Institute of Occupational Hygienists’ recommended guidance as a benchmark for monitoring DPM exposure.
Whatever applies to your site, our air monitoring reports give you a definitive answer about whether the relevant limit is being exceeded. With the new national limit coming into effect, now is a good time to find out where your workplace actually stands.
Controlling exposure to DPM
As part of Airsafe’s assessment of the DPM risk to your workers, our occupational hygiene team can recommend appropriate control measures to lower exposure. Our recommendations follow the standard hierarchy of controls, with elimination of the hazard as the best possible solution, followed by substitution, isolation, engineering controls, administrative controls, and personal protective equipment.
For diesel particulate matter specifically, some of the controls recommended by the Cancer Council are:
- Engine selection: replacing diesel engines with gas or electric, or choosing low-emission engines.
- Fuel selection: using low-emission diesel fuels, additives and lubricants where possible.
- Emission control devices: fitting devices that reduce emissions, like particulate filters, catalytic converters, scrubbers and cyclones.
- Enclosed equipment: designing and maintaining air-conditioned cabs where possible.
- Ventilation: using both local exhaust and forced dilution ventilation.
- Maintenance and repairs: keeping a maintenance schedule for all engines and emission-control equipment.
- Testing of exhaust components: using raw exhaust tests to measure how well exhaust treatments are working.
- Engine operation: running engines to optimise combustion, and turning them off when not in use.
- Worker education and training: training workers on the hazards and the procedures used to manage them.
- Sharing activities: rotating tasks between workers to reduce the time each spends exposed to diesel exhaust.
- Administrative controls: scheduling work to minimise the number of workers near the plant while it’s operating.
- Personal protective equipment (PPE): air-supplied or air-purifying respiratory protection that filters particulates.
Why choose Airsafe?
Airsafe is one of Australia’s most respected occupational hygiene consultancies, and we’ve been measuring airborne contaminants since 1988. As our name implies, air quality monitoring is one of our core activities – we have the equipment and the expertise to monitor for a wide range of airborne contaminants, diesel particulate among them, and we can run both spot assessments and ongoing portable or fixed monitoring with daily checks.
For DPM compliance sampling, Airsafe is accredited by NATA for volume measurement: we collect the samples on site using NATA-accredited equipment, then send them to a dedicated NATA-accredited laboratory for respirable elemental carbon analysis. All our test reports carry metrological traceability.
DPM rarely sits on its own. The same diesel plant that puts particulate into the air usually brings noise, and often dust, along with it. Rather than dealing with each hazard in a piecemeal manner, you’re better off with a holistic approach – and with the same team able to assess the lot in one engagement, you’re not left coordinating several consultants for one site.
4.9 stars from over 600 Google reviews and counting, from builders, contractors, miners and industrial clients across Australia.
“We recently appointed Airsafe to undertake air monitoring and reporting at a brownfield development site during the demolition stage. Their proactive, professional and cost and time-efficient approach and implementation were excellent.”– Carl O. Peterson, December 2021
“I use Airsafe on a regular basis for commercial construction. Liam Matthews and the Airsafe team always get the job done professionally, safely, and in a prompt manner as required. If only I could give more stars.”– Jordan Kissane, September 2021
“AIRSAFE has become our go-to company for all air monitoring needs. Working for a large paint company, we’ve found their service not only exceptional but also backed by valuable advice. They are consistently reliable, flexible, and a pleasure to work with. These qualities made it an easy decision to choose them as our preferred supplier.”– Nik Pappas, November 2025
FAQs
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Diesel particulate matter (DPM) is the fine, sooty particles in diesel engine exhaust – tiny carbon particles with other substances stuck to them, including carcinogens like polycyclic aromatic hydrocarbons. They’re small enough to penetrate deep into the lungs and stay airborne for a long time. DPM is a Group 1 carcinogen, linked to lung cancer and possibly bladder cancer, and it’s the second most common workplace carcinogen after UV radiation. Short-term, it irritates the eyes, nose, throat and lungs.
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Any workplace running diesel plant or vehicles, especially where the exhaust can build up – think mining and tunnelling, vehicle workshops, loading docks, warehouses, partially enclosed roadways and similar. The risk is highest in enclosed, poorly ventilated spaces. Workers commonly exposed include miners, construction and oil-and-gas workers, forklift and truck drivers, loading-dock and vehicle-maintenance workers, and stevedores. If you operate diesel machinery and you’re not sure where you stand, call us on 1300 888 338 and we’ll help you work it out.
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There is now. For a long time there was no national standard – only standards for some individual exhaust components, plus a mining-industry standard in states like NSW. From 1 December 2026, diesel particulate matter is included for the first time in the new national workplace exposure limits, measured as respirable elemental carbon. The NSW mining standard (0.1 mg/m3 as an eight-hour average) still applies to mines and petroleum sites. Whatever applies to your site, our monitoring reports give you a definitive answer about whether the limit is being exceeded.
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It depends on what you need. For a compliance result, we take samples on site under our NATA accreditation for volume measurement, then have them analysed for respirable elemental carbon – the standard measure of DPM – by a dedicated NATA-accredited laboratory, so the results carry metrological traceability. For ongoing oversight, we also offer portable and fixed monitoring solutions, and once a program is operational we check the equipment daily. Either way, we start with a risk assessment, then report clearly on what was found, how it compares against the relevant limit, and what to do about it.
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Yes, and it usually makes sense to. The diesel plant that generates DPM tends to generate noise, and often dust, as well. With our holistic approach to occupational hygiene, the same team can assess all of it in one go, so you’re not coordinating several consultants for one site. Just call us on 1300 888 338 to talk through what your workplace needs.
Contact us about diesel particulate monitoring today
Airsafe provides expert DPM risk assessment and monitoring – spot assessments, and portable or fixed monitoring solutions with daily checking. With a national exposure limit for diesel particulate matter taking effect in December 2026, it’s worth knowing where your workplace stands now.
We work across Sydney, NSW and Australia, with travel built into our quotes for sites further afield.
If your business uses diesel, don’t put your workers at risk. Contact us for a fast quote, or call Airsafe on 1300 888 338.
Last updated: May 2026
