More information can be found in the Guidance on interpretation of Workplace exposure standards for airborne contaminants on Safe Work Australia ’ s website .
WHS Regulation clause 50 Monitoring airborne contaminant levels
A PCBU must ensure that air monitoring is carried out to determine the airborne concentration of silica dust in a worker ’ s breathing zone , if necessary , to determine :
− − whether there is a risk to a worker ’ s health , or if the PCBU is not certain whether silica dust levels exceed the workplace exposure standard .
Air monitoring can also be used to :
− check the effectiveness of control measures , including any new control measures − inform workers of their pattern of exposure − determine the right level of respiratory protection , and − inform health monitoring requirements .
Air monitoring does not prevent disease and is not an alternative to implementing effective control measures .
A PCBU should ensure air monitoring is conducted by an independent , competent person . For example , a certified occupational hygienist or a person with recognised equivalent competency under an international certification scheme .
Air monitoring to determine a worker ’ s exposure involves measuring the level of silica dust in the breathing zone of workers using a personal sampler during their usual shift activities , including routine breaks . Figure 2 shows an approximation of a worker ’ s breathing zone .
Figure 2 : Worker ’ s breathing zone .
Managing the risks of respirable crystalline silica from engineered stone in the workplace - Code of Practice 20 of 57