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Standard Interpretations - Table of Contents
• Standard Number: 1910.134; 1910.134(g)(1); 1910.134(g)(1)(i); 1910.134(g)(1)(i)(A); 1910.134(g)(1)(i)(B)

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

September 20, 1995

Brad Johnson
Excelsior Fire Department
339 Third Street
Excelsior, Minnesota 55331

Dear Mr. Johnson:

This letter is in response to your April 27, 1995, and June 28, 1995, inquiry to Mr. Charles Adkins concerning the appropriateness of using Mag-1 Eyewear eyeglass holders with full face piece respirators and self-contained breathing apparatus (SCBA). Please accept my apologies for the delay in answering your inquiry. At this time OSHA does not accept the use of any eyeglass attachment which would intervene between a respirator face piece and the skin of the wearer. The reasoning for this is set forth below. The Agency will however forward the information provided to the National Institute of Occupational Safety and Health (NIOSH) for review and consideration. A future reconsideration of your request may be initiated when the results of NIOSH's review are available.

The question on wearing eyewear under a full facepiece respirator has been problematic for some time. As you point out in your April 27 letter, the approved spectacle kits which are available for respirators are not without drawbacks, and not everybody can wear contact lenses. While contact lenses are technically prohibited by the OSHA respirator standard, an administrative interpretation has suspended this prohibition after a review and consultation with interested parties found there was no scientific support to substantiate a hazard based upon this practice. Your request to the Agency regarding the MAG-1 requires a similar burden of proof of the Agency, i.e., to develop sufficient consensus that the utilization of the subject articles provides equivalent protection to the respirator user.

[This document was edited on 03/30/99 to strike information that no longer reflects current OSHA policy.]

NIOSH is recognized by law as the approving agency for respirators. In this capacity, it has developed a respirator policy which precludes any condition that prevents a complete seal between the respirator face piece and the wearer's face. This concept has also been incorporated into OSHA's respirator standard under [29 CFR 1910.134.(g)(1)(i)], which states, "respirators shall not be worn when conditions prevent a good face seal. Such conditions may be a growth of beard, sideburns, a skull cap that projects under the face piece or temple pieces on glasses."
[Correction 03/30/99]
[1910.134(g)(1)] Facepiece seal protection.
(i) The employer shall not permit respirators with tight-fitting facepieces to be worn by employees who have:
(A) Facial hair that comes between the sealing surface of the facepiece and the face or that interferes with valve function; or
(B) Any condition that interferes with the face-to-facepiece seal or valve function.
Clearly the use of the Mag-1 projects under the face piece of the respirator and could be construed as a prohibited condition which would affect a good face seal.

OSHA had previously received a request from Criss Optical Company, the manufacturer of the MAG-1, for permission to use the device with any full face piece respirator. Two respirator quantitative fit testing studies using spectacle straps were submitted by Criss Optical for review.

These studies were conducted by the Los Alamos National Laboratory (LANL) and Bruce Held, a private consultant. The Agency also requested the OSHA Training Institute and the Norton Company to conduct quantitative fit testing on negative pressure full face piece respirators to provide additional information. The identification of the spectacle straps were not identified as MAG-1 in all of these studies but the results may still be applicable to the issue.

Both the OSHA Training Institute study and the Norton Research & Development Department study indicate a lower protection factor for negative pressure respirators with the use of the spectacle strap than without. The magnitude of this effect was shown to be increased if the strap was twisted. The Held study showed little difference in protection factor when using the spectacle strap than without using it. The Held study also showed a decrease in the protection factor if the strap was twisted. The LANL study is the most extensive study and includes both negative and positive pressure respirators. The positive pressure respirators showed no significant difference with the protection factors when wearing and not wearing MAG-1. One model of SCBA did exhibit a decrease in duration of cylinder use. There was a significant difference in the protection factor obtained with two respirators but not with a third. Finally, the study stated limitations which included a limited selection of respirator types and not addressing user factors, such as poor donning practice, twisted MAG-1 straps, hard work, extreme body movements, etc.

In sum, these studies indicate a negative effect of the MAG-1 on the protection factors achieved with negative pressure respirators and no significant effect on the protection factors achieved for pressure-demand SCBA respirators. However, a potential for the decrease in the duration of cylinder usage may indicate the MAG-1 is interfering with a the face seal. The negative indications, along with the uncertainty of the user controlled factors, make the issue a complex one in nature especially given the importance of good vision for personnel wearing respirators. OSHA is, therefore, submitting the package of studies, together with the administrative history of your requests, to NIOSH's Division of Safety Research. It is hoped that this agency, with their expertise in respirators, will be able to evaluate the information and provide an opinion on whether the MAG-1 is interfering with a good face seal.

If you have any questions on this matter, please contact [the Office of General Industry Enforcement at (202) 693-1850]. Thank you for your interest in safety and health.


Steve Mallinger
Acting Director of Technical Support

[Corrected 8/15/2007]

Standard Interpretations - Table of Contents

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