Feasibility of a new method to determine respirator performance by biological monitoring of exhaled air.
Decker JA; Crutchfield CD
J Int Soc Respir Prot 1993 Jan; 11(1):6-19
A new approach to determining respirator performance as a function of measuring actual subject exposures to a challenge agent by breath analysis was developed. The breath analysis approach eliminated particle size effects, increased test rigor by using a more challenging test agent (a vapor in place of an aerosol), and eliminated in mask sampling problems by using exhaled breath as an index of worker exposure. In this pilot study of the method, concentrations of chlorofluorocarbon-113 in exhaled breath were correlated at 30 minutes after exposure to a generated challenge concentration when a full facepiece negative pressure respirator was worn at rest in the exposure chamber. A high degree of correlation was noted between resting respirator performance and controlled negative pressure fit factors. There was little correlation found between the protection factors and fit factors based on in mask sampling techniques. No correlation was found between the controlled negative pressure and in mask sampling methods. As it was a complex and time consuming technique, the authors do not expect that it will be routinely applied to measuring respirator performance. However, it may be useful in describing with much greater clarity actual levels of protection afforded to subjects by a wide range of respirator types during simulated workplace protection factor studies. Used in well designed studies, this method could establish a more solid basis for assigning protection factors to classes of respirators. The method may also help clarify the relationship between respirator fit factors and respirator performance.
Respiratory-protective-equipment; Personal-protective-equipment; Respiratory-protection; Equipment-design; Equipment-reliability; Testing-equipment; Inhalants
Journal of the International Society for Respiratory Protection