§ 751.511 — Interim workplace controls of chrysotile asbestos exposures.

40 CFR § 751.511

• Title: Title 40: Protection of Environment
• Part: Part 751: Regulation of Certain Chemical Substances and Mixtures Under Section 6 of the Toxic Substances Control Act
• Source: eCFR (current through Apr 16, 2026)

Text

§ 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).

(ii) Owners or operators must use exposure monitoring methods that conform with the OSHA Reference Method specified in appendix A of 29 CFR 1910.1001 or an equivalent method. If an equivalent method is used, the owner or operator must ensure that the method meets the following criteria:

(A) Replicate exposure data used to establish equivalency are collected in side-by-side field and laboratory comparisons; and

(B) The comparison indicates that 90% of the samples collected in the range 0.5 to 2.0 times the ECEL or the lowest concentration possible have an accuracy range of plus or minus 25 percent of the OSHA Reference Method specified in appendix A of 29 CFR 1910.1001 at a 95 percent confidence level as demonstrated by a statistically valid protocol. The NIOSH 7402 analytical method may be applied to adjust the analytical result to include only chrysotile asbestos.

(6) Notification of exposure monitoring results. (i) The owner or operator must, within 15 business days of receipt of monitoring results, notify each potentially exposed person of these results either individually in writing or by posting the results in an appropriate location that is accessible to all potentially exposed persons. The notice must be in plain language and understandable to all potentially exposed persons.

(ii) The written notification required by paragraph (c)(6)(i) of this section must include the corrective action being taken by the owner or operator to reduce exposure to or below the ECEL, wherever monitoring results indicated that the ECEL had been exceeded.

(d) Regulated areas—(1) Establishment. Beginning November 25, 2024 the owner or operator must establish regulated areas wherever airborne concentrations of chrysotile asbestos exceed, or there is a reasonable possibility that they may exceed, the ECEL.

(2) Demarcation. The owner or operator must demarcate regulated areas from the rest of the workplace in a manner that minimizes the number of persons who will be exposed to chrysotile asbestos.

(3) Access. The owner or operator must limit access to regulated areas to authorized persons or other persons required by work duties to be present in regulated areas.

(4) Provision of respirators. The owner or operator must supply a respirator selected in accordance with paragraph (f) of this section to each person entering a regulated area and must require the use of such respirator.

(5) Prohibited activities. The owner or operator must ensure that persons do not eat, drink, smoke, chew tobacco or gum, or apply cosmetics in the regulated area.

(e) Exposure Control Procedures and Plan—(1) Exposure Controls. (A) The owner or operator must institute engineering controls and work practices to reduce and maintain airborne chrysotile asbestos concentrations to or below the ECEL, except to the extent that the owner or operator can demonstrate that such controls are not feasible.

(B) Wherever the feasible engineering controls and work practices that can be instituted are not sufficient to reduce airborne chrysotile asbestos concentrations to or below the ECEL, the owner or operator must use them to reduce exposures to the lowest levels achievable by these controls. If the feasible engineering controls and work practices cannot reduce exposures to or below the ECEL, the owner or operator must supplement the controls by providing and requiring the use of respiratory protection that complies with the requirements of paragraph (f) of this section.

(2) Exposure Control Plan Requirements. (i) Beginning March 28, 2025, when the airborne chrysotile asbestos concentrations exceed the ECEL, or are reasonably expected to exceed the ECEL, owners and operators must establish and implement an exposure control plan to reduce exposures to all potentially exposed persons to or below the ECEL by means of engineering controls and work practices, and by the use of respiratory protection where required under paragraph (e)(1)(B) of this section. The exposure control plan must be available to persons exposed to chrysotile asbestos.

(ii) The exposure control plan must be reviewed and updated as necessary, but at least annually, to reflect any significant changes in the status of the owner or operator's compliance with the requirements of this section.

(iii) The owner or operator must not implement a schedule of personnel rotation as a means of compliance with the ECEL.

(iv) The exposure control plan must include:

(A) An explanation of the exposure controls considered, a rationale for why exposure controls were selected or not selected, based on feasibility, effectiveness, and other relevant considerations;

(B) Descriptions of actions the owner or operator must take to implement the exposure controls selected, including proper installation, maintenance, training, or other actions, and the estimated timeline for implementing such controls;

(C) Description of activities conducted by the owner or operator to review and update the exposure control plan to ensure effectiveness of the exposure controls, identify any necessary updates to the exposure controls, and confirm that all persons are properly implementing the exposure controls; and

(D) An explanation of the procedures for responding to any change that may reasonably be expected to introduce additional sources of exposure to chrysotile asbestos, or otherwise result in increased exposure to chrysotile asbestos, including procedures for implementing corrective actions to mitigate exposure to chrysotile asbestos.

(f) Respiratory protection—(1) Method of Compliance. Beginning November 25, 2024, if an owner or operator is required to provide respiratory protection pursuant to paragraphs (d)(4) or (e)(1)(B) of this section, the owner or operator must provide each potentially exposed person with a respirator according to the requirements of this section.

(2) Respirator program. For purposes of this paragraph (f)(2), the cross-referenced provisions in 29 CFR 1910.134 applying to an “employee” also apply equally to potentially exposed persons, and provisions applying to an “employer” also apply equally to owners or operators.

(i) Owners and operators must select respiratory protection that properly fits each affected person and communicate respirator selections to each affected person consistent with the requirements of 29 CFR 1910.134(f) and 1910.134 app. A.

(ii) Owners and operators must provide, ensure use of, and maintain (in a sanitary, reliable, and undamaged condition) respiratory protection that is of safe design and construction for the applicable condition of use consistent with the requirements of 29 CFR 1910.134(g) through (j) and 1910.134 app. B-1 to B-2.

(iii) Prior to or at the time of initial assignment to a job involving potential exposure to chrysotile asbestos, owners and operators must provide training and retraining to all persons required to use respiratory protection consistent with 29 CFR 1910.134(k).

(3) Respirator selection. Owners or operators must select and provide appropriate respirators based on the most recent exposure monitoring. The minimum respiratory protection that must be provided is as follows:

(i) If the most recent exposure monitoring indicates that the exposure concentration is at or below the 0.005 f/cc (ECEL): no respiratory protection is required.

(ii) If the most recent exposure monitoring indicates that the exposure concentration is above 0.005 f/cc (ECEL) and less than or equal to 0.05 f/cc (10 times the ECEL):

(A) A half-mask supplied-air respirator (SAR) or airline respirator operated in demand mode; or

(B) A half-mask self-contained breathing apparatus (SCBA) respirator operated in demand mode (Assigned Protection Factor 10).

(iii) If the most recent exposure monitoring indicates that the exposure concentration is above 0.05 f/cc (10 times the ECEL) and less than or equal to 0.125 f/cc (25 times the ECEL): A loose fitting facepiece supplied-air respirator (SAR) or airline respirator operated in continuous flow mode (Assigned Protection Factor 25).

(iv) If the most recent exposure monitoring indicates that the exposure concentration is above 0.125 f/cc (25 times the ECEL) and less than or equal to 0.25 f/cc (50 times the ECEL):

(A) A full facepiece supplied-air respirator (SAR) or airline respirator operated in demand mode; or

(B) A half-mask supplied-air respirator (SAR) or airline respirator operated in continuous flow mode; or

(C) A half-mask supplied-air respirator (SAR) or airline respirator operated in pressure-demand or other positive-pressure mode; or

(D) A full facepiece self-contained breathing apparatus (SCBA) respirator operated in demand mode; or

(E) A helmet/hood self-contained breathing apparatus (SCBA) respirator operated in demand mode (Assigned Protection Factor 50).

(v) If the most recent exposure monitoring indicates that the exposure concentration is above 0.25 f/cc (50 times the ECEL) and less than or equal to 5 f/cc (1,000 times the ECEL): A full-facepiece supplied-air respirator (SAR) or airline respirator operated in pressure-demand or other positive-pressure mode (Assigned Protection Factor 1,000).

(vi) If the most recent exposure monitoring indicates that the exposure concentration is above 5 f/cc (1,000 times the ECEL) and less than or equal to 50 f/cc (10,000 times the ECEL):

(A) A full-facepiece self-contained breathing apparatus (SCBA) respirator operated in pressure-demand or other positive-pressure mode; or

(B) A helmet/hood self-contained breathing apparatus (SCBA) respirator operated in pressure-demand or other positive-pressure mode (Assigned Protection Factor 10,000).

(vii) The respiratory protection requirements in paragraph (f)(3) of this section represent the minimum respiratory protection requirements, such that any respirator affording a higher degree of protection than the required respirator may be used.

(g) Workplace information and training. (1) By November 25, 2024, the owner or operator must institute a training program and ensure that persons potentially exposed to chrysotile asbestos participate in the program according to the requirements of this paragraph (g).

(2) The owner or operator must train each potentially exposed person prior or at the time of a potential exposure to chrysotile asbestos and at least annually thereafter.

(3) The owner or operator must ensure that information and training is presented in a manner that is understandable to each person required to be trained.

(4) The following information and training must be provided to all persons potentially exposed to chrysotile asbestos:

(i) The health effects associated with exposure to chrysotile asbestos, based on the most recent publication by EPA, OSHA, NIOSH, and/or CDC;

(ii) The quantity, location, manner of use, release, and storage of chrysotile asbestos and the specific operations in the workplace that could result in exposure to chrysotile asbestos, noting where each regulated area is located;

(iii) The specific procedures implemented to control exposures and manage occupational risks to persons potentially exposed to chrysotile asbestos, such as engineering controls, work practices and personal protective equipment to be used; and

(iv) The requirements of this section, as well as how to access or obtain a copy of these regulations.

(5) Whenever there are workplace changes, such as modifications of tasks or procedures or the institution of new tasks or procedures, or when the airborne concentration of chrysotile asbestos increases, or when the exposure control plan is updated according to paragraph (e)(2)(ii) of this section, the owner or operator must update the training and re-train each potentially exposed person.