Crystalline Silica: why it's important to manage exposure in the workplace
Exposure to Crystalline Silica has been a topic of increasing interest over recent years as it has presented itself as a significant risk in the wake of inadequate control measures and elevated silica dust levels among people working in stonemasonry, construction and the mining industries. When workers cut, crush, drill, polish, saw or grind products that contain silica, dust particles are formed. Depending on factors, such as how much dust a worker breathes in and for how long, crystalline silica can lead to serious and fatal lung disease such as silicosis.
Silica testing and air monitoring
Under the Australian Work Health and Safety (WHS) laws, a ‘person conducting a business or undertaking’ (PCBU) must identify hazards, assess risks and implement practical controls to protect workers’ health and safety. This includes monitoring the health and safety of workers if they carry out ongoing work using, handling, generating or storing crystalline silica, and there is a significant risk to the worker’s health because of exposure.
Air monitoring and testing can determine the airborne concentration of respirable crystalline silica, which can reduce hazardous exposures and prevent illness in your workplace.
Make informed decisions with an accredited laboratory
Our Perth laboratory, MPL Laboratories is a national leader in airborne CONTAM monitoring and analysis. MPL Laboratories are NATA Accredited for Respirable Dust (AS 2985) and have been for Crystalline Silica by re-deposition and FTIR (NIOSH 7603) for over 20 years!
In 2021, MPL Laboratories further extended its scope of NATA accreditation to include the analysis of Respirable Crystalline Silica (RCS) on filters using the X-ray diffraction (XRD) technique.
A comparison of respirable crystalline silica concentration measurements
Evaluation and control of respirable crystalline silica exposures are critical components of an effective occupational hygiene program. The two techniques, FTIR (after re-deposition) and XRD offer advantages and disadvantages, depending on the nature of the samples collected. Each suffers from interferences of different types and if these cannot be overcome using one method, the best option is to revert to the other.
By having access to both methods of analysis in-house, we are able to not only provide XRD for those clients operating in mineralogy with known FTIR interferences (e.g. Feldspars, Amorphous Silica), but also provide XRD as a follow-up when such interferences are observed using the FTIR technique.
Above, α-Quartz and Cristobalite peaks by XRD
XRD at our Perth lab, MPL Laboratories
MPL Laboratories Reporting Limits
| Analyte |
Based on Method Ref |
Reporting Limit (mg/filter)# |
Reporting Limit (mg/m³ )#
(assume 1080L
sample volume) |
Safe Work Australia and
Worksafe NZ
- OEL (TWA) |
XRD
(Direct on Filter) |
ISO 16258-1; |
25mm filter: |
|
|
| α-Quartz |
MDHS 101-2; |
0.005 mg/filter |
0.005 mg/m³ |
0.05 mg/m³ |
| Cristobalite |
NIOSH 7500
(Direct on Filter) |
0.01 mg/filter |
0.01 mg/m³ |
0.05 mg/m³ |
FTIR
(Redeposition) |
|
|
|
|
| α-Quartz |
NIOSH 7603 |
0.005 mg/filter |
0.005 mg/m³ |
0.05 mg/m³ |
| Cristobalite |
In-house |
0.02 mg/filter |
0.02 mg/m³ |
0.05 mg/m³ |
# Based on filters not being overloaded or suffering with matrix interferences.
Experienced and dedicated to your laboratory testing needs
MPL Laboratories and our network of Envirolab Services laboratories and support offices across Australia offer sample testing services, which will provide you with accurate reporting for more informed decisions concerning compliance and your obligations in keeping your workers safe, healthy and productive.
Our service also incorporates the extensive experience and expertise of our individual team members in meeting the requirements of your project:
With many years' experience in processing large quantities of dust samples for both private and public sector clients, MPL Laboratories has streamlined the analytical process – even with ashing and re-deposition required for the FTIR analysis. These same principles have been applied to the XRD analysis of the filters and a turnaround of 5 working days is available on either technique.
Please note, some forms of silica analysis have special testing requirements, such as Amorphous Silica (e.g. Fumed Silica, Silica Fume) and thermally generated Tridymite. If you are specifically interested in these forms, make sure to contact the team prior to submitting samples.
Find out more about our capabilities in work health
Your employees are the most important part of your business. That's why it's important that your workplace environment is healthy and safe for all your staff.
Our specialisation in OHS and hygiene monitoring encompasses a wide scope of areas that Envirolab has the expertise and know-how in providing you with quality results:
Additional information and resources
Requirements for employers vary between the Australian states and territories. However, in 2019, the Australian Governement established a National Dust Disease Taskforce to develop a national approach for the prevention, early identification, control and management of occupational dust diseases, including silicosis in Australia.
From 1 July 2020, the workplace exposure standard (WES) for silica was halved from an eight-hour time-weighted average of 0.1 mg/m3 to 0.05 mg/m3 under the Work Health and Safety Regulations. The new standard was agreed upon by work health and safety ministers following a review of safe exposure levels by Safe Work Australia.
Safe Work Australia’s national guide for Working with Silica and Silica Containing Products also provides information about controlling the risks of exposure to silica dust when working with silica and products containing silica, including composite (engineered or manufactured) stone used to fabricate kitchen and bathroom benchtops, bricks, asphalt and cement.
