Diesel Exhaust Exposure in Transport and Logistics

Diesel engines are a common part of transport and logistics operations, from trucks and forklifts to yard vehicles and equipment used in fleet maintenance facilities.

Their exhaust can also expose workers to a mixture of gases and fine particles. Exposure is not limited to drivers. Loading dock workers, warehouse employees, mechanics and others working around diesel-powered equipment may also be exposed, particularly where engines operate in enclosed or partially enclosed areas.

This is an important issue for transport and logistics businesses to review ahead of Australia’s new Workplace Exposure Limits (WELs), which take effect on 1 December 2026.

A new Workplace Exposure Limit will apply to diesel particulate matter (DPM):

0.01 mg/m³, measured as respirable elemental carbon.

Safe Work Australia has identified transport and logistics as one of the industries where workers may be exposed to diesel engine emissions.

→ Safe Work Australia: Guide to Managing the Risks of Exposure to Diesel Engine Emissions in the Workplace

For an overview of the wider changes, read JTA’s Workplace Exposure Limits Are Changing.

Where can diesel exhaust exposure occur?

Transport and logistics workplaces can have multiple diesel exhaust sources. The level of exposure will depend on factors such as the number and type of diesel engines, how frequently they operate, ventilation, work practices and how close workers are to the source.

Workers do not need to operate diesel equipment themselves to experience exposure. For example, exhaust from a loading dock may enter an adjoining warehouse, while mechanics can work close to running engines during servicing and diagnostic work.

The whole working environment therefore needs consideration, not just the person driving the vehicle.

What does the new diesel particulate matter limit mean?

Australia will transition from Workplace Exposure Standards (WES) to Workplace Exposure Limits (WELs) on 1 December 2026.

As part of the change, diesel particulate matter will have a WEL of:

0.01 mg/m³, measured as respirable elemental carbon.

This gives transport and logistics businesses a clear reason to review diesel exhaust exposure before the new limits commence.

A workplace should consider where diesel engines operate, which workers may encounter their emissions, how long and how frequently exposure occurs, and what controls are already in place.

Safe Work Australia provides further guidance on assessing and controlling diesel engine emissions in the workplace.

→ Safe Work Australia diesel engine emissions guidance

Loading docks, warehouses and distribution centres

Loading docks can place workers close to diesel engines throughout the day.

A single truck may only spend a relatively short period at a loading bay, but employees can work around repeated vehicle arrivals, departures and idling across an entire shift. Enclosed and partially enclosed loading areas can also reduce the ability of exhaust to disperse.

Warehouses may have additional exposure sources. Diesel-powered forklifts or other plant may operate inside the building, while exhaust from trucks can enter through adjoining loading areas and doorways.

The potential for exposure will depend on the circumstances at each site, including:

• the number and type of diesel engines;
• how frequently and how long they operate;
• engine condition;
• the size and configuration of the building;
• natural and mechanical ventilation;
• the location of exhaust sources; and
• where workers spend their time.

A large warehouse does not necessarily mean diesel exhaust will disperse adequately. The way vehicles, workers and ventilation interact needs to be considered.

Fleet maintenance workshops

Fleet workshops can present a different exposure profile because mechanics and maintenance workers may work close to operating engines.

Exposure may occur when workers start engines indoors, undertake diagnostic testing, leave engines running during repairs or move trucks through the workshop.

Where engines need to operate indoors, the effectiveness of ventilation and exhaust extraction becomes particularly important.

Maintenance activities can also generate other airborne contaminants through welding, cutting, grinding, painting, solvents and degreasers. An occupational hygiene assessment can consider these exposures as part of the broader working environment.

Learn more about JTA’s Occupational Hygiene services.

Reducing diesel exhaust exposure

Businesses should eliminate exposure to diesel engine emissions where reasonably practicable. Where elimination is not reasonably practicable, they should reduce exposure so far as is reasonably practicable.

The hierarchy of controls provides the framework for deciding how to manage the risk.

Practical measures in a transport or logistics workplace can include:

• replacing diesel-powered equipment with electric or other alternatives where reasonably practicable;
• switching off trucks, forklifts and other diesel engines when they do not need to run;
• reducing unnecessary vehicle idling;
• separating workers from diesel exhaust sources;
• reviewing traffic routes and vehicle movements to reduce worker exposure;
• providing sufficient natural or mechanical ventilation, particularly in enclosed or partially enclosed areas;
• using local exhaust extraction where engines need to operate indoors; and
• maintaining engines and emission-control systems.

Businesses should prioritise higher-order controls rather than relying on respiratory protective equipment where other reasonably practicable controls are available.

Respiratory protective equipment may form part of the overall control strategy in some circumstances, but it should not replace reasonably practicable measures that eliminate, isolate or reduce the source of exposure.

When should you consider exposure monitoring?

A workplace assessment can identify diesel exhaust sources, potentially exposed workers and existing controls. Where uncertainty remains about the level of exposure, personal exposure monitoring can provide further information.

Occupational hygienists can use personal air monitoring to assess what a worker encounters within their breathing zone while carrying out normal tasks.

For diesel particulate matter, monitoring uses respirable elemental carbon to assess exposure against the new WEL.

Rather than monitoring every employee, an occupational hygienist may establish Similar Exposure Groups (SEGs) by grouping workers who undertake comparable tasks under similar conditions.

In a transport operation, these groups might include loading dock workers, warehouse employees, forklift operators, fleet mechanics, yard workers and drivers.

Monitoring can help determine the level of exposure, identify activities contributing to exposure and assess whether existing controls adequately reduce worker exposure.

Preparing for 1 December 2026

Transport and logistics businesses still have time to review diesel exhaust exposure before the new WEL takes effect.

A practical starting point is to walk through the site and follow diesel-powered vehicles and equipment through their normal activities:

Arrival → loading and unloading → warehouse or yard movements → maintenance → departure

Consider where engines run, where workers spend their time, whether exhaust can accumulate or travel into occupied areas and what controls currently reduce exposure.

Where the level of exposure remains uncertain, occupational hygiene assessment and monitoring can provide the evidence needed to determine the next steps.

JTA has also outlined how the broader WEL changes affect different sectors in Industries Most Affected by Australia’s 2026 Workplace Exposure Limits.

How JTA can help

JTA’s occupational hygienists can help transport and logistics businesses identify diesel exhaust sources, assess potentially exposed workers, establish Similar Exposure Groups, undertake personal exposure monitoring and recommend practical controls.

With the new Workplace Exposure Limits commencing on 1 December 2026, now is a good time to understand your workplace exposure profile and address any gaps in your existing controls.

Detect the exposure. Protect your people.

Talk to JTA about occupational hygiene and exposure monitoring

1300 856 282