- OSHA Lead in Construction Advisor
1926.62 (c) PERMISSIBLE EXPOSURE LIMIT
(c)(1) The employer shall assure that no employee is exposed to lead at concentrations greater than fifty micrograms per cubic meter of air (50 ug/m(3)) averaged over an 8-hour period.
(c)(2) If an employee is exposed to lead for more than 8 hours in any workday 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 ug/m(3)) = 400 divided by hours worked in the day.
(c)(3) When respirators are used to limit employee exposure as required under paragraph (c) of this section and all the requirements of paragraphs(e)(1) and (f) of this section 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.