Crystalline Silica Substances and Air Monitoring Notification

This bulletin provides general information on requirements in relation to working with crystalline silica substances. New laws about crystalline silica substances commenced in the Territory on 01 September 2024.

Crystalline silica substances

Crystalline silica substances (“CSS”) are materials that contain at least 1% crystalline silica by weight.

Processing of crystalline silica substances

Processing of CSS is any process that exposes, or is likely to expose, a person to respirable crystalline silica (“RCS”) during the manufacture or handling of a CSS. Processing includes:

• the use of power tools or mechanical plant to crush, cut, grind, trim, sand, abrasive polish or drill a CSS
• the use of roadheaders to excavate material that is a CSS
• the quarrying of material that is a CSS
• mechanical screening involving a material that is a CSS or
• tunnelling through material that is a CSS.

Duty for processing of crystalline silica substances to be controlled

A person conducting a business or undertaking (“PCBU”) must not carry out or direct or allow a worker to carry out the processing of a CSS unless the processing is controlled.

When processing of crystalline silica substances is controlled

The processing of a crystalline silica substance is controlled if:

• control measures that eliminate or minimise the risk arising from the processing of CSS are used and
  • at least one 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 and
• a person still at risk of being exposed to RCS after one or more of the above measures are used is provided with and wears respiratory protective equipment while the work is carried out.

Identifying processing of crystalline silica substances that is high risk

A PCBU at a workplace must assess the processing of a CSS to determine if the processing is high risk. If a determination is unable to made, the processing of the CSS is taken to be high risk.

Silica risk control plan required for high risk processing of crystalline silica substance

A PCBU carrying out the high risk processing of a CSS must ensure that a silica risk control plan for the processing is prepared before processing commences.

Silica risk control plan

The silica risk control plan must:

• identify all high risk processing of a CSS carried out at the workplace
• include the risk assessment undertaken to determine processing of CSS that is high risk
• document what control measures will be used to control the risks associated with the high risk processing and how those measures will be used, monitored and reviewed and
• should be written in a way that is readily understandable by the people who use it.

The silica risk control plan must be:

• available to all workers and
• provided to all workers before they commence the processing.

When a silica risk control plan is not required

In limited circumstances a silica risk control plan is not required. These circumstances are:

• where the processing that is high risk is also high risk construction work and
• a safe work method statement is prepared before the processing commences and
• the safe work method statements addresses all of the requirements of a silica risk control plan.

Duty to train workers about the risks of crystalline silica

A PCBU must ensure that a worker receives crystalline silica training if the PCBU believes the worker may be:

• involved in high risk processing of a CSS or
• at risk of exposure to RCS because of high risk processing of a CSS.

Crystalline silica training

NT WorkSafe inspectors will accept documented evidence that workers have been provided with information and training about the risks associated with exposure to RCS and suitable control measures for processing of CSS. Training should include the following:

• identification of CSS products
• the relevant legislation, guidelines and standards
• the consequence, hazards and risks to health due to exposure to RCS
• exposure standards
• safety data sheets
• hierarchy of controls
• systems for prevention of exposure
• risk assessments and hazards prevention

Training approval from the regulator may not required if documented evidence that workers have been provided with crystalline silica training (including the above content) can be provided upon request.

Air monitoring

A PCBU that is carrying out, or directing or allowing a worker to carry out high risk processing of a CSS must undertake air monitoring.

Air monitoring must also be undertaken by a PCBU if the person is unsure whether or not the airborne concentrations of RCS is exceeds the workplace exposure standard.

If there is an exceedance of the workplace exposure standard of 0.05mg/m3 during an 8 hour time weighted average, air monitoring results must be provided to the regulator:

• as soon as reasonably practicable
• in any event, no more than 14 days from the date the air monitoring result was reported to the PCBU.

Air monitoring results must be recorded and kept for 30 years after the record is made.

Health monitoring

A PCBU must also provide health monitoring for all workers carrying out high risk processing of CSS. Further information about health monitoring requirements is available in Safe Work Australia’s guide for crystalline silica health monitoring at: health-monitoring-guidance-crystalline-silica.pdf (safeworkaustralia.gov.au)

Further information

Further information can be found in Safe Work Australia’s guidance for persons conducting a business or undertaking on working with crystalline silica substances at: Working with crystalline silica substances (safeworkaustralia.gov.au).