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.

October 5, 1998

Mr. William R. Jaggi
Trans World Airlines, Inc.
Ground Operations Center
P.O. Box 10007
St. Louis, MO 63145

Dear Mr. Jaggi:

This is in response to your letter of March 31, addressed to Ms. Bonnie Friedman, in the Occupational Safety and Health Administration's (OSHA's) Office of Public Affairs. We apologize for the long delay of this response. Enforcement of this standard will begin on the compliance date, October 5, 1998.

In your letter, you requested clarification on several respiratory protection issues. There were several statements listed that you sought to determine if they were true or not. The statements are responded to in the same order as given in your letter.

Please note that in your letter, you used the term "medical surveillance." The respiratory protection standard 1910.134 uses the term "medical evaluation."

  1. Statement:  Use of the disposable paper type dust respirators does not require medical surveillance.

    Response:  Non-voluntary use of a filtering facepiece (dust mask/disposable paper type dust respirator) requires that the employer establish and implement a written respiratory protection program with worksite-specific procedures. The respiratory protection program must include the medical evaluation of employees.

    Voluntary use of a filtering facepiece respirator does not require medical evaluation. The employer needs only to ensure that the dust masks are not dirty or contaminated, that their use does not interfere with the employee's ability to work safety, and provide a copy of Appendix D to each voluntary wearer.
  2. Statement:  Use of an air supplied positive pressure face mask does not require medical surveillance unless intended for rescue or emergency purposes.
  3. Statement:  Use of an air supplied positive pressure hood does not require medical surveillance unless intended for rescue or emergency purposes.

    Response:  The new respiratory protection standard, 29 CFR 1910.134, states, "The employer shall provide a medical evaluation to determine that the employee's ability to use a respirator, before the employee is fit tested or required to use the respirator in the workplace." Employees that use any respirators including respirators such as air supplied positive pressure face masks or hoods must have a medical evaluation before use. Medical evaluations are needed to prevent injuries and illnesses that can arise from respirator use. Clinical studies show that even positive pressure respirator use can harm an employee. Respirator use of all kinds can cause alterations in breathing patterns, hypoventilation, retention of carbon dioxide, and an increase in workload on the body.

Please note that on [November 2004, OSHA published Respiratory Protection Frequently Asked Questions. This document contains guidance and interpretations on the most frequently asked questions.] The section on medical evaluations and the attachments may be particularly helpful in developing your respiratory protection program. This can be found on the Internet on the OSHA Home Page at http://www.osha.gov.

Should you require any additional information on this matter, please, feel free to contact [the Office of Health Enforcement at (202) 693-1850].


Richard E. Fairfax
Acting Director
Directorate of Compliance Programs

[Corrected on 10/20/06]