title: How protective are respirator assigned protection factors: an uncertainty analysis.
abstract: This investigation evaluated the risk of overexposure for a selected assigned protection factor by performing Monte Carlo simulations. A model was constructed to assess respirator performance by calculating the concentration inside the respirator. Estimates of the factors that affect respirator performance were described as distributions. The distributions used a worst case estimate for concentration in the workplace, the worst case for respirator performance (the fifth percentile person), and the worst case for exhalation valve leakage. A Monte Carlo analysis then provided estimates of the percentage of time that concentration inside the respirator exceeded the occupational exposure limit (OEL). For a half-facepiece respirator with an APF of 10, the calculations indicated a low risk of being exposed above an OEL, with mean exposures being controlled well below an OEL.
authors.affiliation: NIHS Inc., Ardentown, DE 19810, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Nelson
authors.forename: M A
authors.initials: MA
authors.lastname: Jayjock
authors.forename: C E
authors.initials: CE
authors.lastname: Colton
mesh_terms: D006801:Humans; D009010:Monte Carlo Method; D012134:Respiratory Protective Devices / Q000592:standards*; D012306:Risk; D020711:Threshold Limit Values