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 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 that exceeds exposure standards and mines must ensure worker exposure is as low as reasonably practicable.

Changes to airborne contaminants and dust exposure standards guidance poster

Changes to airborne contaminants and dust exposure standards guidance poster

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.

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

Silicosis video
Silicosis body posterSilicosis hierarchy of controls poster
View the videoDownload the posters

The position paper below details our regulatory approach during the period of July - December 2020 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.

Revision to coal exposure standard

The new respirable coal dust workplace exposure standard of 1.5mg/m3 will take effect in NSW from 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.

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 will commence on 1 February 2021.

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.