Standard Interpretations - Table of Contents
• Standard Number: 1910.134(h)(3)(iii)

August 19, 2005

Mr. Zeferino N. Chavez
Ralphs Grocery Company
1500 Eastridge Avenue
Riverside, CA 92507

Dear Mr. Chavez:

Thank you for your April 15, 2005 letter to the Occupational Safety and Health Administration (OSHA) requesting clarification of OSHA's requirement in their Respiratory Protection Standard (29 CFR 1910.134) to maintain air cylinders in a fully charged state. Specifically, you requested whether a 60-minute breathing-air cylinder for SCBAs need to be recharged, when its pressure falls below 90% of the full charge. This letter constitutes OSHA's interpretation only of the requirements discussed, and may not be applicable to any question not delineated within your original correspondence.

Paragraph (h)(3) in 1910.134 sets the minimum requirements employers must follow in their inspection of respirators that may be used by their employees. The purpose of the paragraph is to ensure proper functioning of respirators used by employees. In your letter, you stated that your company has equipped your hazardous-response SCBAs with 60-minute air cylinders rather than the minimum 30-minute cylinders specified by paragraph 1910.134(h)(3). OSHA encourages employers to exceed the minimum criteria provided in our standards, and we commend you for providing cylinders that could provide increased protection for your employees. However, your letter later asks, given that these cylinders contain more air, would 60-minute cylinders be in compliance with paragraph 1910.134(h)(3)(iii), if they were allowed to drop to 75% of the manufacturer's recommended pressure level before they were recharged?

The answer is no, the requirement in paragraph 1910.134(h)(3)(iii) requires cylinders to be maintained in a fully charged state. While this paragraph allows for s