Airborne contaminants and dust

An airborne contaminant is a fume, mist, gas, vapour, dust or other microorganism that is a potentially harmful substance to which individuals may be exposed in their working environment.

Airborne contaminants are generated during mining activities and can be a risk to a person’s health if not properly managed. Individuals can be exposed to dust on a mine site, with activities such as cutting or grinding, abrasive blasting, hauling, mucking, tipping, and crushing, having the potential to create unacceptable dust exposures if not controlled properly.

Substantial dust can be generated during drilling operations, particularly if undertaken in dry conditions. Also, workers can be exposed to dust from dried spilled material or generated from tailings storage facilities, product stockpiles and during the loading of broken material and product transfer.

The aim is to reduce airborne contaminants and dust generation. The order in which controls are implemented must follow the hierarchy of controls – elimination, substitution, engineering, administrative and lastly personal protective equipment. Personal protective equipment is a last line of defence against exposure.

In NSW mines, no person is to be exposed to airborne dust and airborne contaminants that exceed exposure standards and mines must ensure worker exposure is as low as reasonably practicable.

Changes to airborne contaminants and dust exposure standards guidance poster (PDF, 291.57 KB)

Silica dust

One of the most common dusts encountered on mine sites is silica dust or Respirable Crystalline Silica (RCS). A significant amount of silica is present in most rocks, clays, sands, gravel and shale. Exposure to silica dust can lead to the development of lung cancer, silicosis (an irreversible scarring and stiffening of the lungs), kidney disease and chronic obstructive pulmonary disease.

Silica control plan

The new crystalline silica management provisions in Chapter 8A of The Work Health and Safety Regulation 2017 commenced on 1 September 2024. Chapter 8A requires persons conducting a business or undertaking (PCBUs) to control high risk processing of a crystalline silica substances and to have a silica control plan to prevent worker exposure to hazardous concentrations of respirable crystalline silica.

The Regulator considers compliance with sections 28, 106, 107, 124, schedule 1(8) and schedule 2(1) of the WHS (MPS) Regulation to be compliant with clauses 529A-529CE of the WHS Regulation with the following exceptions:

Respirable protective equipment (RPE) is to comply with AS/NZS 1716:2012, Respiratory protective devices, and AS/NZS 1715:2009, Selection, use and maintenance of respiratory protective equipment
A crystalline silica substance contains at least 1 percent crystalline silica, determined as a weight/weight (w/w) concentration.

Read the Resources Regulators position paper for further information (PDF, 264.03 KB).

Revision to silica exposure standard

The new respirable crystalline silica workplace exposure standard of 0.05mg/m3 took effect in NSW from 1 July 2020. The new exposure standard is prescribed following a revision of the Workplace Exposure Standards for Airborne Contaminants (WESFAC).

Mines and petroleum sites will need to report exceedances of the new exposure standard to the NSW Resources Regulator from 1 July 2020.

Resources: Silicosis is entirely preventable campaign

Additional resources

The resources below detail our regulatory approach to assist the NSW mining industry in managing the transition to compliance with the new exposure standard.

Coal dust

Coal miners are at risk for respiratory diseases caused by coal mine dust. Inhaled, coal dust remains in the lungs. Long-term exposure can cause coal mine dust lung disease also known as black lung disease. Miners with combined exposures to coal and crystalline silica dust can also get mixed dust pneumoconiosis. Because it cannot be cured, prevention is critical.

Register of licences for sampling and analysing airborne dust (PDF, 59.93 KB)

Revision to coal exposure standard

The new respirable coal dust workplace exposure standard of 1.5mg/m3 commenced in NSW on 1 February 2021.

Mines and petroleum sites will need to report exceedances of the new exposure standard to the NSW Resources Regulator from 1 February 2021.

Black Lung Disease campaign

Diesel emissions

Diesel exhaust emissions contain a complex mixture of gases, vapours, aerosols and particulate matter. Most mines use diesel engines in some form.

Underground miners are exposed to concentrations of diesel particulate matter that are significantly higher than those in any other occupation.

All mines should have a documented strategy to control diesel emissions to minimise people’s exposure to the lowest level reasonably practicable.

Fact sheet Diesel particulate matter personal exposure monitoring and exceedance notification (PDF, 309.51 KB)

Diesel Particulate Exposure Standard for NSW mines

NSW is the first mining jurisdiction in Australian to implement an exposure standard for diesel particulate matter. The exposure standard of 0.1mg/m3 commenced on 1 February 2021.

Resources

The resource below details our regulatory approach to assist the NSW mining industry in managing compliance with the new exposure standard.

Position paper: Diesel particulate matter exposure standards implementation (PDF, 1.59 MB)

Regulatory focus

A recent resurgence in identified cases of coal worker pneumoconiosis and simple silicosis in the NSW mining industry have kept this issue an ongoing focus for the Resources Regulator. An extensive and state wide, targeted assessment program of work, has been ongoing since 2016. This issue remains a high priority and future assessment reports will be published as they are completed.

Carbon dioxide

Carbon dioxide is a naturally occurring gas emitted in coal mines from accumulation in coal seams when they were formed. It is also exhaled by mine workers and released in the combustion processes of machinery used in the mines and explosives used in coal blasting. In NSW there are coal seams that contain not only methane gas but carbon dioxide gas as well. It has been identified as an airborne contaminant and in seam carbon dioxide is associated with other principle hazards such outburst.

Mine Operators of an underground coal mine are required by the Work Health and Safety (Mines and Petroleum Sites) Regulation 2022 to develop and implement safety management systems and procedures to manage worker exposures to carbon dioxide. This obligation includes the monitoring of worker exposures and notification of exceedances to the Regulator.