Processing of a crystalline silica substance

Processing of a crystalline silica substance (CSS) or commonly referred to as silica, may involve:

  • the use of power tools or mechanical plant to carry out an activity involving the crushing, cutting, grinding, trimming, sanding, abrasive polishing or drilling of a CSS, or
  • the use of roadheaders to excavate material that is a CSS, or
  • the quarrying of a material that is a CSS, or
  • mechanical screening involving material that is a CSS, or
  • tunnelling through a material that is a CSS, or
  • a process that exposes, or is reasonably likely to expose, a person to respirable crystalline silica (RCS) during manufacture or handling of a CSS (for example cleaning and maintenance processes such as sweeping that may disturb settled RCS).

This definition is designed to capture all activity with silica that has the potential to generate and expose workers or others at the workplace to RCS.

Controlled processing of CSS

A PCBU must not carry out, or direct or allow a worker to carry out, processing of a CSS unless the processing is controlled.

Processing of a crystalline silica substance (CSS) is controlled if:

  • control measures to eliminate or minimise risks arising from the processing are implemented so far as is reasonably practicable and,
  • at least 1 of the following measures are used during the processing:
    • the isolation of a person from dust exposure
    • a fully enclosed operator cabin fitted with a high efficiency air filtration system
    • an effective wet dust suppression method
    • an effective on-tool extraction system
    • an effective local exhaust ventilation system.
  • a person still at risk of being exposed to RCS after 1 or more of the measures listed above are used is:
    • provided with appropriate respiratory protective equipment, and
    • wearing the respiratory protective equipment correctly while the work is carried out.