Master of Science - Research
School of Health and Society
Burton, Kerrie Anne, Efficiency of respirator filter media against diesel particulate matter, Master of Science - Research thesis, School of Health and Society, University of Wollongong, 2015. http://ro.uow.edu.au/theses/4550
Diesel engines have been a mainstay within many industries since the early 1900’s. Exposure to diesel particulate matter (DPM) is a major issue in many industrial workplaces given the potential for serious health impacts to exposed workers, including lung cancer and adverse cardiovascular and irritant effects. Personal respiratory protective devices are a common safety measure to mitigate worker exposure against the damaging health impacts of DPM, and to protect they need to act as effective filters.
Filtering efficiency of respiratory protection is determined by challenging filter media with specified test aerosols to calculate penetration at designated flow rates. However, the methodology outlined in AS/NZS1716 (Standards Australia International Ltd & Standards New Zealand 2009) does not account for the differences in structure, particle size and chemical characteristics of DPM and the specified test aerosol sodium chloride, nor increased breathing rates typical in labour intensive work environments. For these reasons, a more effective test strategy / model is required.
Three commonly used AS/NZS certified respirator filters were challenged with diesel emissions from both a small diesel generator and an industrial sized diesel engine to assess the filter efficiency of these varying sources of diesel emissions. Penetration of elemental carbon (EC), total carbon (TC) and Total Particulate Matter (TPM) at the standard designated flow rate, as well as a higher flow rate representative of heavy work, was determined for the small diesel generator. Penetration of EC, TC and TPM at the standard designated flow rate was determined for the larger engine. Results indicate that filtering efficiency assumed by P2 certification in Australia was achieved for two of the three respirator models at the designated flow rate, and for potentially only one respirator model at a higher flow rate for the smaller diesel generator. For the larger diesel engine at the standard designated flow rate, filtering efficiency by EC, TC and TPM met the requirements for P2 certification. These findings indicate that current respiratory protection certification standards may not ensure adequate protection for respirator users against diesel particulate matter.