Respiratory protection is a widely used control in many industries, including both underground and open cut mining, to protect workers from exposure to diesel emissions.
Recent research undertaken by Burton, Whitelaw and Jones (CSHST 2015-16 Project 20634 & WorkCover). Applied Research grant 2015/005356) evaluated penetration of DPM through eight commonly used respirator filters, at the flow rate designated in the standard, as well as at two higher flow rates representative of medium to heavy work. The results indicate that when challenged with DPM, measured as elemental carbon, the filtering efficieny assumed by P2 certification (<6%) in Australia was not achieved for some respirators. We found that DPM penetration through some of the P2 respirators commonly used in mining; exceeded the filtering efficiency for P2 certification in Australia after a reasonably short wear time. Powered air purifying respirators (PAPRs) are also used extensively in mining workplaces, and may be used increasingly due to changing standards on recommendations on work rates outlined in ISO/TS 16976-4:2012. Without data on PAPRs, our knowledge is incomplete and there is uncertainty around whether wearers of these devices are adequately protected.
This study was conducted to determine whether currently utilised powered air purifying respirators (PAPRs) effectively filter out Diesel Particulate Matter and provide worker protection; by challenging PAPR filters used in mining workplaces with DPM; and by measuring the EC and the sizes of particles that are penetrating the filters to determine whether that poses an additional health risk for workers. The effectiveness of respiratory protection was evaluated in accordance with AS/NZS 1716. Further analysis of three filter models was undertaken using current NaCl and Paraffin standards certified methods and challenge aerosols, to enable comparison with the study results. These studies raise concerns regarding the adequacy of the respiratory protection commonly provided against DPM and highlights the importance of continuing evidence based research to ensure respiratory protection provided to workers prevents inhalation of DPM and subsequent serious health effects