Section 325.51154. Exposure monitoring generally.

(1) Determinations of employee exposure shall be made from breathing zone air samples that are representative of the 8-hour TWA and 15-minute STEL of each employee.

(2)    Representative 8-hour TWA employee exposures shall be determined on the basis of 1 or more samples that represent full-shift exposure for each shift for each job classification in each work area. Representative 15-minute short-term employee exposures shall be determined on the basis of 1 or more samples that represent 15- minute exposures associated with operations that are most likely to produce exposures above the excursion limit for each shift for each job classification in each work area.

(3)    If an employer can document that exposure levels are equivalent for similar operations in different work shifts, the employer need only determine representative employee exposure for  that  operation  during 1 shift.

History: 1988 AACS; 1993 AACS.