Additional Posthearing Comments of the National Institute for Occupational Safetyand Health on the Occupational Safety and Health Administration Proposed Rule on Occupational Exposure to Methylene Chloride by R. W. Niemeier, April 25, 1994

摘要

This testimony contains specific information and comments from NIOSH regardingthe proposed ruling on occupational exposure to methylene-chloride (75092) in the paint stripping and flexible foam production industries. The concerns revolve around the recommendations concerning local ventilation, the solvent degreasing tank, push/pull ventilation, localized strategies, the use of a fan, and dilution ventilation as determined in research with the furniture refinishing industry. A recent publication of NIOSH described a localized dilution ventilation system using an axial fan that permitted concentrations of methylene-chloride ranging from 19 to 110 parts per million (ppm) with an average of 65 ppm. Eight hour time weighted average concentrations for two workers were 48 ppm and 1 ppm, stripping for 323 minutes and 24 minutes, respectively.