[Histonet] Air changes per hour

[Lisa S. Black]

OSHA's "Occupational Exposure to Hazardous Chemicals in Laboratories; Final Rule" (Federal Register January 31, 1990) went into effect May 1, 1990.  Section C.4 (f) of Non-Mandatory Appendix A indicates that 4-12 room air changes per hours (ACH) of fresh air are normally adequate if local exhaust systems such as hoods are used as the primary method of control.