Integrated Unit Performance Testing of Powered, Air-Purifying Particulate Respirators Using a DOP Challenge Aerosol

Abstract

Although workplace protection factor (WPF) and simulated workplace protection factor (SWPF) studies provide useful information regarding the performance capabilities of powered air-purifying respirators (PAPRs) under certain workplace or simulated workplace conditions, some fail to address the issue of total PAPR unit performance over extended time. PAPR unit performance over time is of paramount importance in protecting worker health over the course of a work shift or at least for the recommended service lifetime of the PAPR battery pack, whichever is shorter. The need for PAPR unit performance testing has become even more important with the inception of 42 CFR 84 and the recent introduction of electrostatic respirator filter media into the PAPR market. This study was conducted to learn how current PAPRs certified by the National Institute for Occupational Safety and Health would perform under an 8-hour unit performance test similar to the dioctyl phthalate (DOP) loading test described in 42 CFR 84 for R- and P-series filters for nonpowered, air-purifying particulate respirators. In this study, entire PAPR units, four with mechanical filters and one with an electrostatic filter, were tested using a TSI Model 8122 Automated Respirator Tester, with and without the built-in breathing machine. The two, tight-fitting PAPRs, both with mechanical filters, showed little effect on performance resulting from the breathing machine. The two loose-fitting helmet PAPRs indicate that unit performance testing without the breathing machine is a more stringent test than testing with the breathing machine under the conditions used. The PAPR with a loose-fitting hood gave inconclusive results as to which testing condition is more stringent. The PAPR unit equipped with electrostatic filters gave the highest maximum penetration values during unit performance testing.

Field-Testing Method for Loose-Fitting Powered Air-Purifying Respirators Equipped with HEPA Filters

“…These studies used workplace protection factor (WPF) and simulated WPF (SWPF) studies to better understand the protection level offered by PAPRs under occupational or in situ condition. [10][11][12][13] A WPF study is conducted at the job site under normal working conditions and operation, while a SWPF is done in a laboratory where conditions can be more closely controlled and repeated from test to test. The results of these studies sometimes demonstrated significant differences in the APF and the actual measured workplace performance.…”

Preference and User Experience with Powered Air- purifying Respirators in Healthcare Workers in a Simulated Work Environment: A Pilot Study

“…Martin et al found that for the loose-fitting PAPRs, the performance test without the breathing machine proved more rigorous but the results were inconclusive for the tight-fitting PAPR. The results also showed that a PAPR with an electrostatic filter produced the highest penetration values (Martin et al, 2006). Their results show that PAPR unit performance and the use of an electrostatic filter are both areas of concern in PAPR use.…”

“…The study found no correlation between quantitative fit factors and workplace protection factors. Due to some of the controversy regarding APFs, some individuals in the respirator standard community, manufacturers and industrial sectors have focused on both the WPF and the simulated workplace protection factor (SWPF) (Martin et al, 2006).…”

“…and "fail to address the issue of total PAPR unit performance over extended time" (Martin et al, 2006). Martin et al performed a specific 8-hour test using a dioctyl phthalate (DOP) loading test on 5 PAPRs, of which two were loose-fitting, two were tight-fitting and one used an electrostatic filter.…”