Abstract of article in the Journal of Agricultural Safety and Health, 4(4):255-266, November 1998

Review of Ambient Aerosol Test Procedures in ASAE Standard S525. William A. Heitbrink,* Ronald M. Hall,** Laurence D. Reed,⁺ and Dennis Gibbons^#

In November 1997, the American Society of Agricultural Engineers (ASAE) approved ASAE Standard S525. This standard provides performance specifications for environmental enclosures that are intended to protect operators from pesticide exposures during application. As part of ASAE Standard S525, optical particle counters and ambient aerosol are used to quantitatively evaluate the performance of these enclosures. This consensus standard specifies that the enclosure shall provide a 50:1 reduction in exposures for particles in a range of 2 to 4 µm aerodynamic diameter. ASAE Standard S525 also states that the filters shall be at least 99% efficient for particles larger than 3 µm. Data collection involves using two optical particle counters to measure aerosol concentrations inside and outside the cab during at least four different sessions. Statistical tests, specifically t-tests, are used to evaluate adherence to the standard. Because the test procedure can be complicated by aerosol generation in the cab, sophisticated judgment is needed before testing and data accumulation begin. The article's purpose is to review the basis for the ambient aerosol testing procedures, as specified in ASAE Standard S525, and to point out the standard's pitfalls.

*Corresponding author, Research Chemical Engineer, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, R5, Cincinnati, Ohio 45226, voice (513) 841-4376, fax (513) 841-4506, e-mail wah2@cdc.gov.

**Industrial Hygienist, U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Division of Physical Sciences and Engineering, Cincinnati, Ohio.