Standard Interpretations - Table of Contents 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 some loss of air in these cylinders, it requires them to be recharged whenever the pressure falls to 90% of the manufacturer's recommended pressure level. Larger cylinders are not provided greater latitude by the standard. They must be maintained in a fully charged state and recharged when the pressure falls below 90%.

Appropriate respirators must be selected by the employer for employee use and must be regularly inspected and maintained to the minimum requirements stated in paragraph 1910.134(h)(3). Exceeding the requirement of one paragraph does not allow an employer to relax compliance with the requirement specified by another paragraph.

As you may be aware, the California Department of Industrial Relations (Cal/OSHA) administers an OSHA-approved state occupational safety and health program for both private and public sector employers and employees in California. State plans are required to implement regulations that are "at least as effective" as the federal standards. If you would like further information regarding California&39;s occupational safety and health requirements, you may contact the California Department of Industrial Relations at the following address:
John Rea, Acting Director
California Department of Industrial Relations
P.O. Box 420603
455 Golden Gate Avenue, 10th Floor
San Francisco, California 94102
Phone: (415) 703-5050
Fax: (415) 703-5059
Thank you for your interest in occupational safety and health. We hope you find this information helpful. 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 If you have any further questions, please feel free to contact the Office of Health Enforcement at (202) 693-2190.


Richard E. Fairfax, Director
Directorate of Enforcement Programs

Standard Interpretations - Table of Contents Standard Interpretations - Table of Contents