§ 751.511 Interim workplace controls of chrysotile asbestos exposures.
(a) Applicability. This section applies to processing and commercial use of chrysotile asbestos, including any chrysotile asbestos-containing products or articles, for chrysotile asbestos diaphragms in the chlor-alkali industry; and to the commercial use of chrysotile asbestos sheet gaskets for titanium dioxide production.
(b) Interim Existing Chemical Exposure Limit (ECEL). Beginning November 25, 2024, the owner or operator must ensure that no person is exposed to an airborne concentration of chrysotile asbestos in excess of the interim ECEL for chrysotile asbestos of 0.005 fibers (f)/cubic centimeter (cc) as an eight (8)-hour time-weighted average (TWA). Where an owner or operator cannot demonstrate exposure at or below the ECEL, including through the use of all technically feasible engineering controls or work practices as described in paragraph (e)(1) of this section, and has not demonstrated that it has appropriately supplemented with respiratory protection that complies with the requirements of paragraph (f) of this section, this will constitute a failure to comply with the ECEL.
(c) Exposure monitoring—(1) In general. (i) Owners or operators must determine each potentially exposed person's exposure from personal breathing zone air samples that are representative of the 8-hour TWA exposure of each potentially exposed person.
(ii) Representative 8-hour TWA of a potentially exposed person's exposure must be determined on the basis of one or more samples representing full-shift exposures for each shift for each potentially exposed person in each job classification in each work area.
(2) Initial exposure monitoring. No later than November 25, 2024 each owner or operator covered by paragraph (a) of this section as of May 28, 2024, must perform initial exposure monitoring of all potentially exposed persons.
(3) Periodic exposure monitoring. The owner or operator must establish an exposure monitoring program for periodic monitoring of exposure to chrysotile asbestos. If one or more samples representing full-shift exposures from the most recent exposure monitoring exceeds the ECEL (>0.005 f/cc 8-hour TWA), periodic exposure monitoring is required within three months of the most recent exposure monitoring. Otherwise, periodic exposure monitoring is required within six months of the most recent exposure monitoring.
(4) Additional exposure monitoring. The owner or operator must conduct additional exposure monitoring within a reasonable timeframe after there has been a change in the production, process, control equipment, personnel or work practices that may result in new or additional exposures above the ECEL or the owner or operator has any reason to suspect that a change may result in new or additional exposures above the ECEL.
(5) Method of monitoring. (i) Exposure monitoring samples must be personal breathing zone samples collected and analyzed using methods and quality control procedures described in Appendix A to 29 CFR 1910.1001, or as referenced in Appendix A to 29 CFR 1910.1001 (Appendix B to 29 CFR 1910.1001, OSHA method ID-160, or the NIOSH 7400 method).