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.

August 18, 1986

Mr. Jack Manning
442 King Street
Woodbury, New Jersey 08096

Dear Mr. Manning:

This is in response to your letter of May 5 regarding respiratory protection.

We will begin by answering your second question and then will answer the remainder of your questions in the order that you asked them.

The MSA Model 401 Air Mask(TM) is a type of respirator mask that must form a seal with the wearer's skin in order to function at maximum effectiveness. Thick growths of hair where the mask edges meet the skin prevent the formation of a seal. Therefore, employers may not use this particular mask to protect employees who have thick hair growth at points where the seal with the skin is supposed to form. To do so would be a violation of 29 CFR [1910.134(g)(1)(i-iii)].

We can envision a chemical plant where the potential for accidental release of a toxic chemical is such as to warrant the providing of respirators for emergency use for the entire workforce. If that were the case and the employer chose to provide MSA Model 401 Air Masks for the employees, then as stated above, none of the employees may have thick hair growth at points where the seal with their skin is supposed to form.

In answer to all three parts of your third question, any time an employee is in a situation requiring respiratory protection and the respirator worn by the employee will not form a seal at some point where it is designed to do so the employer is put in the position of being in violation of 29 CFR [1910.134(g)(1)(i-iii)].

The amount and frequency of training to provide individuals assigned to conduct emergency rescue operations is whatever is necessary in order that the individuals attain and retain the ability to perform the associated duties and functions satisfactorily.

[This document was edited on 03/22/99 to strike information that no longer reflects current OSHA policy.]

We appreciate the opportunity to address your concerns. If you need our assistance again, please do not hesitate to contact us.


John B. Miles, Jr., Director
Directorate of Field Operations