OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

May 22, 1989

MEMORANDUM  FOR:   Linda R. Anku
                  Regional Administrator

THROUGH:           Leo J. Carey, Director
                  Office of Field Programs

FROM:              Patricia K. Clark, Acting Director
                  Directorate of Compliance Programs

SUBJECT:           29 CFR 1910.1025 - Respiratory Protection

This is in response to your letter of April 13, 1989 concerning the subject captioned above. Your interpretation of the respiratory protection requirements of the lead standard is correct.

The values for the airborne concentrations of lead in air presented in 29 CFR 1910.1025, Table II, represent the maximum concentrations at which the corresponding respirator can be used. These values are actual concentrations and not time weighted averages. The parenthetical values (e.g.; 10 x PEL) represent only the derivation of these concentrations.

If we may be of further assistance regarding this matter, contact Joseph Hopkins of my staff at FTS 523-8036.

April 13, 1989

                  Directorate of Compliance Programs

THROUGH:           LEO CAREY, Director
                  Office of Field Programs

FROM:              LINDA R. ANKU
                  Office of Field Programs

SUBJECT:           29 CFR 1910.1025 - Respiratory Protection Interpretation

Table II of 29 CFR 1910.1025 lists required respiratory protection for protection against lead. The table lists concentrations of exposure followed by the corresponding concentration in relationship to the permissible exposure limit, e.g. "not in excess of 0.5 mg/meter cubed (10X PEL)". Recently, the wording of the table caused some confusion as to whether the exposure to determine appropriate respiratory protection was to be a time-weighted-average (based on the definition of permissible exposure limit) or an upper limit of concentration based on the phrase "not in excess of 0.5 mg/meter cubed..."

It is our understanding that respiratory protection is to be based on the upper limit of concentration for lead since the values in parentheses, i.e. "10X PEL", are intended to demonstrate only the derivation of the lead concentration for determining the appropriate respiratory protection. This would also agree with the NIOSH protocol for approving respirators. Our understanding of this issue was confirmed with Joseph Hopkins of the Office of Health Compliance Assistance. Due to the potential for this issue arising again, we are requesting written confirmation of this interpretation.

Please contact Jim Johnston of my staff (FTS 596-1201) if there are any questions.