WAC 296-155-17607
Permissible exposure limit. (1) The
employer shall assure that no employee is exposed to lead at
concentrations greater than fifty micrograms per cubic meter of
air (50 µg/m3) averaged over an 8-hour period.
(2) If an employee is exposed to lead for more than 8 hours
in any work day the employees' allowable exposure, as a time
weighted average (TWA) for that day, shall be reduced according
to the following formula:
Allowable employee exposure (in µg/m3) = 400 divided by
hours worked in the day.
(3) When respirators are used to limit employee exposure as
required by this section and all the requirements of WAC 296-155-17611(1) and 296-155-17613 have been met, employee
exposure may be considered to be at the level provided by the
protection factor of the respirator for those periods the
respirator is worn. Those periods may be averaged with exposure
levels during periods when respirators are not worn to determine
the employee's daily TWA exposure.
[Statutory Authority: Chapter 49.17 RCW. 93-22-054 (Order
93-07), § 296-155-17607, filed 10/29/93, effective 12/10/93.]