Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

December 8, 1997

Stephen C. Wilson
Flowserve Corporation
P.O. Box 8820
Dayton, OH 45401-8820

Dear Mr. Wilson:

This is in response to your August 6 letter requesting clarification on whether a plastic shield you manufacture may be used in compliance with Occupational Safety and Health Administration (OSHA) requirements for machine and machinery guarding in the workplace. Please accept our apology for the delay in responding. Your scenario and questions and our replies follow.


Flowserve manufactures and markets a one piece splash and shaft/shield that envelopes the open areas between a pump bearing housing and the pump casing. Paragraph 3.2.1(c) of the American Society of Mechanical Engineers (ASME) Standard B15. la-1997 requires that guards for mechanical power transmission apparatus utilize fasteners that "shall not be readily removable by people other than authorized persons."


Can a plastic shield for which fasteners are not utilized (as required by the aforementioned ASME standard) be used in the workplace in compliance with OSHA requirements under the following conditions? The shield is of a con-figuration that it covers the hazard, does not displace readily and is sufficiently strong to prevent a falling person from coming in contact with the hazard.


In your letter you stated that "fasteners for guards are only required by OSHA on power presses, and that fasteners are not required by the guarding requirements contained on 29 CFR 1910.219 (which appears to apply to our pumps)." You are correct that the guarding requirements under paragraph 1910.219 apply to your pump shafting. However, under paragraph 1910,219(c)(2)(i), shafting must be protected by a stationary casing enclosing the shafting completely or .... Additionally, under paragraph 1910.219(m)(1), the stationary casing must be securely fastened to the floor or frame of the machine (pump coupling).


In the brochure enclosed with your letter, you stated that your shield "is easy to install or to remove. Simply spread the shield apart... fit around the bearing housing adapter... and snap into place. The spring-like tension holds the shield firmly in place."


The question which your inquiry raises is what is meant by the term "securely fastened" as used in paragraph 1910.219(m)(1). We interpret the term to mean both that the casing cannot be accidentally displaced and that it cannot be easily removed by unauthorized persons. Although the ASME provision which you mentioned has not been incorporated into §1910.219 as a legally binding requirement, it is relevant, we believe, when interpreting and applying the OSHA standard's requirement for a "securely fastened" guard. The ASME provision clearly reflects a concern that the protective purpose of the casing will be defeated if the casing can be easily removed by unauthorized persons. OSHA agrees that there is a need to assure that shaft guards are not easily removable.


From the information (including the brochure) you provided, it would therefore appear that your guard would meet the requirements of neither paragraph 1910.219(m)(1) of the OSHA standard nor paragraph 3.2.1(c) of ASME B15.1a-1997.

We appreciate your interest in employee safety and health. If we can be of further assistance, please contact the Office of Safety Compliance Assistance, Mr. Ronald J. Davies, telephone (202) 219-8031, extension 110.


John B. Miles, Jr., Director
Directorate of Compliance Programs