Methods for determining the RPD protection required

There are different methods for determining what level of Respiratory Device Protection (RPD) protection is required for a given situation or contaminant as outline below

  1. National/state/territory/Industry guidance/requirements detail the type and level of protection for certain hazards/contaminants e.g. Asbestos, Isocyanates. For hazardous substances classified as carcinogens or mutagens, or are a potential cause of occupational asthma, it may be required for these exposures to be reduced to as low as is reasonably practicable or technically feasible and to below and control or exposure control level/limits.
  2. Calculating the hazard ratio using the determined foreseeable worst-case airborne concentration and the relevant occupational exposure limits (OEL), Workplace Exposure Standard (WES) or Workplace Exposure Limit (WEL) values. To calculate the HR, it is necessary to know the foreseeable worst-case concentration(s) of the airborne contaminant(s) and the relevant occupational health regulatory requirements, exposure limits or the safe exposure levels applying to these contaminant(s). RPD with a protection level greater than the hazard ratio should be selected in order to reduce the wearer’s exposure to below the OEL/WES/WEL.
  3. Control banding method which utilises the hazard statements associated with the hazardous substance(s) being used or generated, combined with the potential for inhalation exposure based on the amount of substance used and its dustiness or volatility. This method is provided as an alternative approach to determine the minimum required protection level. Instead of relying on the determination of the foreseeable worst-case concentration(s) of the airborne contaminant(s) and knowledge of the relevant occupational health legislative requirements, OEL/WES/WEL or the safe exposure levels, this approach is acceptable for the control of inhalation exposure, i.e. based on control banding. This procedure does not require the measurement of the airborne inhalation hazard and therefore may be suitable for situations where the actual measurement of the airborne inhalation hazard is impractical. It is only suitable up to a certain level and above this, specialist advice should be sought. 

Reference/s for further information and detail:

  • AS/NZS 1715:2009 – Selection, use and maintenance – Section 4.2.2.2
  • SA/SNZ TS ISO 16975.1:2023 – Selection, use and maintenance – Section 7.2.2 and Annex C