The codes of practice address the effectiveness in determining whether the explosion suppression content of materials supplied is suitable.

This code of practice is being released as part of public comment on the draft NSW Work Health and Safety (Mines) Regulations 2014.

Explosion suppressant materials are used in underground coal mines to prevent coal dust becoming an ignition source for explosions and fire.

Limestone dust has been applied in Australian underground coal mines so that the incombustible content of roadway dust remains above the minimum specified in legislation to prevent ignitions.

The dust must be of a size and quality that is fit for purpose to achieve the intended outcomes of its application.

The use of explosion suppressants must be managed under WHS legislation to ensure that the risk to workers is eliminated if this is reasonably practicable and, if not, that the risk is minimised so far as is reasonably practicable.

Suppressants such as limestone contain constituents that are hazardous to workers who are exposed to it and are identified as not fit for use. This is why it is critical for any explosion suppressant used in underground coal mines to be analysed properly so it is suitable for application.

This code focuses on the quartz (free silica) content in limestone dust, size analysis of stone dust and the methodologies for determining the incombustible content of roadway dust. The mine operator and PCBUs should ensure the most appropriate method of testing is used.

The WHS (Mines) Regulations make provision for the quality of stone dust that must be used in underground coal mines as an explosion suppressant.

It sets a minimum standard for the quality of stone dust that must be used in underground coal mines as an explosion suppressant.

It also sets the minimum mandatory requirements for the incombustible content of roadway dust at an underground mine.