Silica dust

What is silica dust?

Silica is a common naturally occurring mineral, also known as silicon dioxide. Silica can be found or manufactured in different forms, broadly divided into crystalline and non-crystalline (amorphous).

The most common form of silica is quartz. Silica is found in some stones, rocks, sand, gravel and clay. Silica dust can also be found in:

• bricks
• pavers
• tiles, and
• concrete.

When natural stone or rock and other silica containing products are cut, crushed or sanded, dust is released. The very fine portion of the dust that is generated is known as respirable crystalline silica or silica dust.

The ACT Silica Dust Action Plan has outlined work health and safety reforms for silica dust. The reforms include regulatory changes for managing the risks of crystalline silica in the workplace.

Occupations and tasks that can lead to exposure

Work Health and Safety (Crystalline Silica Awareness Training Course and Occupations) Declaration 2022 (The delegation) commenced on the 21/22 July 22 to declare that the training course in Crystalline Silica Exposure Prevention would be required to be completed by specified occupations under Work Health and Safety Regulation 2011 section 418D (2) (A).

The effect of the declaration is that all workers in the specified occupations and those who are reasonably expected to work with silica containing materials must undertake 10830NAT – Course in Crystalline Silica Exposure Prevention before 1 July 2023.

The course is available, RTO can be found here training.gov.au - 10830NAT - Course in Crystalline Silica Exposure Prevention. The below table lists the specified occupations.

The occupations with the greatest risk of exposure to silica dust include:

• miners
• construction workers (both commercial and residential)
• farmers, and
• engineers.

There may be a risk of exposure to silica dust for workers who:

• use power tools to cut or modify engineered stone, for example fabricating and installing kitchen benchtops
• blast, excavate or tunnel into sandstone, clay or granite
• drill, cut or chase into concrete and brickwork
• cut bricks, pavers or tiles
• angle grind on concrete or masonry
• jackhammer, scabble or chisel concrete
• clean up the dust and debris created by the above activities, including dried concrete slurry
• dismantle equipment or disposes of offcuts covered in dust, or
• demolish buildings.

Hazards

The very fine particulates of silica dust present a risk when they become airborne and are inhaled into the lungs. The health risks of silica dust can include chronic obstructive pulmonary disease (COPD, including chronic bronchitis and emphysema), silicosis (an irreversible scarring and stiffening of the lungs), lung cancer (associated with silicosis), kidney disease and auto-immune diseases such as scleroderma.

Many of the diseases caused by silica dust have a long latency, with many of them appearing decades after exposure stops. The increased use of machinery and power tools to replace manual tasks and the increased use of manufactured products high in silica content can result in potentially very high exposures to silica dust in some workplaces.

Risk management

The Work Health and Safety Act 2011 requires employers, in consultation with workers, to identify hazards, assess risks and implement practical controls to protect workers’ health and safety.

The risk of exposure to silica dust from a task is assessed by examining the work processes involving silica or silica containing products. The assessment must consider the dust exposure that could occur. Having airborne dust levels monitored is the most accurate way to assess the risk. However, in some cases the risk may be clear without monitoring (e.g. where there are visible clouds of dust from silica containing materials, such as during dry concrete cutting). It is important to understand that a dust cloud contains a range of different sized particles and the very fine particles of silica dust, that pose the greatest risk to health, stay airborne for longer and may be difficult to see. Monitoring is required to assess the risk from such particles.

New silica dust regulations for the ACT

As a result of industry feedback, amendments have been made to the WHS Regulation 2011:

The new amendment specifies silica control measures that must be considered as a minimum for silica dust. These include:

• wet dust suppression – which includes a number of wet methods such as a continuous feed of water, misting, spraying, foams, pastes and fluids other than water
• isolating the work from others
• on tool dust extraction
• local exhaust ventilation, and
• respiratory protective equipment (RPE).

From 1 November 2022, if you cannot eliminate silica dust from your workplace:

• you must have a continuous feed of water over the cutting area, plus one other silica control measure plus RPE when modifying engineered stone
• when modifying silica containing materials (other than engineered stone) you must:
  • use a continuous flow of water over the cutting site
  • where this is not practicable, then a dust suppression method plus one other silica control measure is to be used
  • where this is not practicable, on tool dust extraction plus one other silica control measure is to be used
  • where this is not reasonably practicable, just a wet suppression method or on tool extraction or a fully enclosed cabin can be used
  • and where this is not reasonably practicable, one silica control measure plus RPE can be used.

There are infringements for non-compliance.

• For engineered stone, you must have at least a continuous flow of water plus one other silica control measure
• For SCM, you must have at least one silica control measure in place.

WorkSafe ACT has begun work on updating the Guidance note for managing silica dust at construction sites to reflect the changes.

The ACT Government has released a fact sheet on the new silica dust safety regulations for the ACT.

PCBUs must supply the relevant personal protective equipment (PPE) that is needed to manage risks. This includes RPE which must be properly fit tested and maintained. WorkSafe ACT is a partner of Respfit which provides information about fit testing and a portal where accredited fit testers can be accessed.

PCBUs must provide the information, training, instruction and supervision that is necessary for workers to carry out their work safely. A new nationally accredited training course has been declared effective from 22 July 2022 and must be completed by 1 July 2023. The instrument declaring the training course and occupations for the mandatory silica dust awareness training requirement can be accessed on the ACT Legislation Register at https://legislation.act.gov.au/ni/2022-354.

For more information on the new regulations for Silica, see the documents below:

• Silica information for the construction industry (DOC) or (PDF)
• Silica information for the Bricklaying businesses (Doc)
• Silica information: Working with Concrete (Doc) or (PDF)
• Silica information for businesses that work with engineered stone 2022 (Doc) or (PDF)
• Silica information for landscaping businesses (Doc) or (PDF)
• Silica information: Natural forms of silica (Doc) or (PDF)

Labelling and safety data sheets

Manufacturers and importers of products containing silica need to determine if workers can be exposed to the respirable fraction of airborne silica dust when working with their products e.g. when cutting. Where exposure to silica dust can occur, products must be appropriately labelled and safety data sheets (SDS) provided in accordance with the Work Health and Safety Regulation 2011.

A person conducting a business or undertaking must also obtain a copy of the safety data sheet and make it readily accessible to workers.

Some products may not require a label and SDS. In these cases, if silica dust is generated when using the products, safety information should be provided in the product safety sheet.

Air monitoring

Air monitoring is a method of measuring airborne hazardous substances. It is not a control measure but can be used to check the effectiveness of the control measures you implement to minimise the risks of exposure to silica dust.

The mandatory limit for silica dust in the ACT is an eight hour time weighted average (TWA) of 0.05 mg/m³. However, there is still a risk to worker health at this concentration. Therefore, exposure must be reduced as far as possible under this TWA.

The Work Health and Safety Regulation 2011 states that the workplace exposure standard must not be exceeded and air monitoring must be conducted if there is a potential risk to health or a possibility that the exposure limits could be exceeded. Adjustments to the workplace exposure standard for silica should be made for extended work shifts, taking into account the longer daily exposure. Air monitoring results must be readily available to workers and records of results kept for 30 years.

A PCBU must review any control measures implemented, if a workplace exposure standard for silica dust has been exceeded.

Health monitoring

The Work Health and  Safety Regulation 2011 states that health monitoring must be provided to workers who are continually working with silica dust and there is a significant risk to the worker’s health.

Health monitoring is carried out or supervised by a specialist doctor and may include:

• answering questions regarding previous occupational and medical history
• a physical examination or a spirometry (lung function test)
• clinical tests – urine or blood samples, and
• X-rays or HRCT.

Health monitoring can help to detect early symptoms of exposure, such as a loss in lung function, before permanent damage occurs. Health monitoring for working with silica and silica containing products should begin before job placement and at least every three years; annually for high-risk jobs such as working with engineered stone. Workers largely employed in high-risk jobs include residential construction workers who fabricate or install engineered stone products, excavators, jackhammer operators or abrasive blasters.

Health monitoring requirements

The PCBU should inform workers about health monitoring requirements before they start work and provide information about:

• what is involved in the health monitoring program, for example how often testing might occur and which tests might be required
• what health monitoring aims to achieve and its benefits
• how and who to report symptoms
• potential health effects from exposure to silica dust
• record keeping requirements, and
• the worker’s health monitoring report.

Who does health monitoring?

Health monitoring must be carried out by, or under the supervision of, a registered medical practitioner (doctor) with experience in health monitoring. Not all of the tests and procedures in a health monitoring program need to be carried out by the doctor. Some can be performed by other suitably qualified people, for example an occupational nurse may ask a worker general questions about their medical history, and collect urine or blood samples. While worker’s will be consulted about the choice of doctor used for the health monitoring, in most cases it will not be the worker’s own medical practitioner unless they have the necessary experience to do the work.

Who pays for health monitoring?

The PCBU who engages the worker must pay all the expenses related to a health monitoring program. These expenses include:

• doctor’s fees
• testing and analysis costs, and
• travel costs.

The PCBU must also allow paid time off work to attend medical appointments for any testing that is needed.

Health monitoring report

The doctor prepares the health monitoring report. It must include:

• worker details, the name and address of the business or undertaking, and the name of the doctor
• any test results that indicate whether or not exposure to silica dust
• any advice that test results indicate a disease, injury or illness as a result of being exposed to silica dust, and
• any recommendations and actions requiring new or changed control measures or medical counselling, including whether a worker can continue work.

The doctor should let the worker know the results of health monitoring and will send a confidential copy of the report to the PCBU. The PCBU must provide a copy of this report to the workers as soon as they are able.

The health monitoring report is a confidential health record and must not be disclosed to another person except in accordance with the Work Health and Safety Regulation 2011 or without the worker’s written consent.

Publications

• Silica information for the construction industry (DOC) or (PDF)
• Silica information for the Bricklaying businesses (Doc)
• Silica information: Working with Concrete (Doc) or (PDF)
• Silica information for businesses that work with engineered stone 2022 (Doc) or (PDF)
• Silica information for landscaping businesses (Doc) or (PDF)
• Silica information: Natural forms of silica (Doc) or (PDF)
• WorkSafe ACT - Managing Silica Dust at Construction Sites (DOC 597KB) or (PDF 344KB)
• WorkSafe ACT - Crystalline Silica Dust Guidance Note (DOC 99KB) or (PDF 222KB)
• Respirable Crystalline Silica and Occupational Health Issues - Australian Institute of Occupational Hygienists (PDF 115KB)
• Silica and the lung (PDF 679KB)
• Breathe Freely Australia - Concrete Sprayer fact sheet
• Breathe Freely Australia - Plasterer fact sheet
• Guide for working with silica and silica containing products – Safe Work Australia
• Workplace checklist: Changes to the workplace exposure standard for silica dust – Safe Work Australia
• Health monitoring for crystalline silica – Safe Work Australia
• Health monitoring guide for PCBUs – Safe Work Australia
• Health monitoring guide for workers – Safe Work Australia
• Silica Dust project (2019) – WorkSafe ACT  (DOC 1,316KB)
• Clean Air. Clear Lungs. | Safe Work Australia