THE LETTERS

摘要

This is in response to your January 15, 2015 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the maintenance and requalification of hermetically sealed fire extinguishers manufactured to meet the requirements of a Department of Transportation (DOT) 4DS specification cylinder and several Special Permits issued by the Pipeline and Hazardous Materials Safety Administration (PHMSA) (e.g., DOT-SP 7026, 7945, 8439, 8495, 10867). We have paraphrased your questions and answered them in the order you provided.