This paper was compiled to give guidance on the assessment, evaluation and control of occupational exposure to RCS, with an emphasis on recommending a health-based occupational exposure guidance value. Reported new cases of silicosis occurring in Australian industries are concerning but appear to be either due to historic poorly controlled long-term exposures or to contemporary acute uncontrolled exposure situations above the current WES.
The AIOH acknowledges the importance of adhering to good control strategies so as to reduce exposures to as low as reasonably practicable (ALARP), particularly for carcinogens. For occupational risk management purposes, the primary aim should be to keep occupational exposures to RCS to ALARP. The AIOH thus supports the 8-hour TWA WES of 0.1 mg/m3 for RCS, as long as worker exposures are at all times limited to ALARP below this limit. The principal reason for this position is that current and historical evidence, including that from the Australian workforce, indicates that if enforced it appears to be protective of the incidence of silicosis, and it is consistent with published threshold levels of effect.
To this end the AIOH recommends that where there is a likelihood of 50% of the exposure standard being exceeded, it should be applied as an action limit which triggers investigation of the sources of exposure and implementation of suitable control strategies as well as health surveillance.
Published December 2018
