Hazardous Materials Regulations: Aluminum Cylinders Manufactured of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, and Oxygen Service-Revised Requalification and Use Criteria

Summary: RSPA proposes to amend requirements in the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) pertaining to aluminum cylinders manufactured using aluminum alloy 6351-T6. The purpose of this rulemaking initiative is to enhance safety, minimize the potential for personal injury and property damage during the cylinder filling process, and adopt a standard for early detection of sustained load cracking (SLC) to reduce the risk of a cylinder rupture.