A Quantitative Fit Test for Dust/Mist Respirators: Part II

Danisch, Susan G.; Mullins, Haskell E.; Rhoe, Carol R.

doi:10.1080/1047322x.1992.10389767

Cited by 5 publications

(3 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This method was intended to be used for filtering facepiece and elastomeric respirators but was not valid for HEPA filters due to a higher pressure drop . Researchers determined that the penetration rate for dust–mist respirators adequately sealed to a mounting plate with hot melt adhesive averaged 0.1%. , Other researchers have demonstrated that particles with 2.0–2.5 μm diameters have an 80–90% penetration rate though face-seal leaks in filtering facepiece respirators even at a low pressure drop …”

Section: Materials and Methodsmentioning

confidence: 99%

“…30 Researchers determined that the penetration rate for dust−mist respirators adequately sealed to a mounting plate with hot melt adhesive averaged 0.1%. 31,32 Other researchers have demonstrated that particles with 2.0−2.5 μm diameters have an 80− 90% penetration rate though face-seal leaks in filtering facepiece respirators even at a low pressure drop. 22 The integrity of a seal for filtering facepiece respirators secured to their mounting plates with hot melt adhesive was evaluated by measuring penetration of monodisperse 2 μm latex spheres at 35 lpm according to the 3 M LPQFT method.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Collection Efficiency Comparison of N95 Respirators Saturated with Artificial Perspiration

Larson

2020

ACS Chem. Health Saf.

View full text Add to dashboard Cite

Due to the COVID-19 pandemic, current high demand for N95 filtering facepiece respirators has placed them in short supply. Filtering facepiece respirator wearers have traditionally been instructed to discard their respirator and don a new one should the respirator become saturated with perspiration or damp from exhaled breath. However, today’s shortage may prohibit many N95 respirator wearers from replacing their filtering facepieces at this desired frequency. Previously unpublished research that evaluated the performance of N95 filtering facepiece respirators saturated with artificial perspiration and then dried out can help provide insight into making critical decisions about the change out frequency of N95 respirators that become damp with use. This study concluded that the collection efficiency of filtering facepiece respirators, containing electrostatic filter media, remained statistically unchanged or slightly improved after being dried out following harsh saturation conditions with artificial perspiration. Therefore, respirator wearers can continue to rely on their N95 filtering facepiece respirators to perform as intended.

show abstract

Section: Materials and Methodsmentioning

confidence: 99%

Section: ■ Materials and Methodsmentioning

confidence: 99%

Collection Efficiency Comparison of N95 Respirators Saturated with Artificial Perspiration

Larson

2020

ACS Chem. Health Saf.

View full text Add to dashboard Cite

show abstract

“…An FF is a protection factor measured during a laboratory quantitative fit test. Further, a major respirator manufacturer acknowledged that correction for particle deposition loss was necessary 24 . That same manufacturer contributed about two‐thirds of the WPFs in OSHA's database, but did not make particle deposition corrections in its own data.…”

Section: Estimation Bias By Not Accounting For Respiratory Tract Depo...mentioning

confidence: 99%

A critique of Occupational Safety and Health Administration's halfmask respirator assigned protection factor

Nicas

2024

Annals of the New York Academy of Sciences

View full text Add to dashboard Cite

Halfmask air‐purifying respirators are used by millions of workers to reduce inhaling air contaminants, both chemical (e.g., asbestos, styrene) and biological (e.g., SARS‐CoV‐2, Mycobacterium tuberculosis). In 2006, the federal Occupational Safety and Health Administration (OSHA) promulgated a standard that gave halfmask respirators an assigned protection factor (APF) of 10. This signified that OSHA assumes a fit‐tested and trained wearer will experience a 10% maximum total inward leakage of contaminated air into the facepiece. To derive APF = 10, OSHA analyzed data from 16 workplace studies of the efficacy of halfmask respirators worn against particulate contaminants. In this commentary, I contend that, in considering the data, OSHA made several errors that overstated halfmask respirator efficacy. The errors were (i) failing to properly account for within‐wearer and between‐wearer variability in respirator efficacy; (ii) ignoring the effect of particle deposition in the respiratory tract; (iii) aggregating unbalanced data within and between studies, and effectively double‐counting the data in some studies; and (iv) ignoring the effect that particle size exerts in penetrating respirator facepiece leak paths. The net result is that OSHA's APF = 10 can lead to excessive toxicant exposure for many workers.

show abstract