{"operation":"document","citation":"11-0175","title":"NitroxFox LLC. — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2011-09-08","effective_on":null,"summary":"11-0175 response to NitroxFox LLC. concerning 172.402, 173.302.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-11-0175.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-11-0175.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-11-0175","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2011/110175.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\n1200 New Jersey Ave\" S.E.\nWashirtgtort, DC 20590\nSEi'0 8 2011\nMr. John Fox\nNitroxFox LLC.\nP.O. Box 32091\nSarasota, Florida 34239\nReference No.: 11-0175\nDear Mr. Fox:\nThis responds to your letter regarding the requirements for compressed gas cylinders\ncontaining breathing enriched air (Nitrox) under the Hazardous Materials Regulations\n(HMR; 49 CFR Parts 171-180). Specifically, you state in your incoming letter that\nDepartment of Transportation (DOT) Specification 3AL (Aluminum) and 3AA (Steel)\ncylinders are commonly used for containment of Nitrox and the air in these cylinders will\nhave elevated levels of Oxygen ranging from 21 % to 100% depending on the application.\nYour questions are paraphrased and answered as follows:\n01: If a cylinder is to be used to transport Nitrox, at what Oxygen percentage must a\ncylinder used for Oxygen service be cleaned and must the cylinder cleaning\nconform to the cleanliness standards specified in 173.302?\nAI: Gas mixtures with Oxygen concentrations greater than 23.5% by volume should be\nconsidered to cause or contribute to combustion of other material to a greater extent\nthan air. These gas mixtures must be described as \"Compressed gas, oxidizing,\nn.o.s.\" and must be classified and labeled with a Division 2.2 (nonflammable gas)\nprimary hazard and a Division 5.1 (oxidizer) subsidiary hazard. If the Oxygen\nconcentration is greater than 23.5%, the conditions specified in § 173.302(b) must\nbe met. Each DOT Aluminum cylinder, including a 3AL cylinder, must be cleaned\nin accordance with the requirements of General Services Administration (GSA)\nFederal Specification RR-C-901D, paragraphs 3.3.1 and 3.3.2 (IBR, see §171.7 of\nthis subchapter). Cleaning agents equivalent to those specified in Federal\nSpecification RR-C-90lD may be used provided they do not react with Oxygen.\nOne cylinder selected at random from a group of 200 or fewer and cleaned at the\nsame time must be tested for oil contamination in accordance with Federal\nSpecification RR-C-90lD, paragraph 4.3.2, and meet the specified standard of\ncleanliness. The HMR does not indicate specific cleaning standards for 3AA steel\ncylinders used for Oxygen service.\n\n<<<PAGE 2>>>\n\nQ2. What is the maximum pressure to which a cylinder can be filled, when charging the\ncylinder with enriched air containing elevated levels of Oxygen? Additionally, is\nthis pressure the same for both aluminum and steel cylinders?\nA2: For aluminum cylinders used for Oxygen service, including 3AL cylinders, the\npressure in each cylinder may not exceed 3000 psig at 21°C (70 OF) as specified in\n§ 173.302(b). The HMR does not indicate a specific operating pressure for steel\ncylinders, including 3AA cylinders, used for Oxygen service, thus, the cyJinder\nmust not exceed the marked service pressure.\nQ3: Maya cylinder contained enriched air (Nitrox) be labeled if the cleanliness\nstandards for Oxygen service have not been met?\nA3: As provided in § 172.402, each package, including cylinders, containing a\nhazardous material shall be labeled with primary and subsidiary hazard labels as\nspecified in column 6 of the Hazardous Materials Table (HMT). If a cylinder is\nfilled with an Oxygen concentration greater than 23.5%, the conditions specified in\n§ 173.302(b), including the appropriate cleaning standards must be met prior to\nbeing offered for shipment. There is no prohibition for labeling a cylinder which\ndoes not meet the appropriate cleaning standards specified in § 173.302(b).\nHowever, this cylinder would not be permitted to be offered for transportation until\nall requirements of § 173.302(b) have been satisfied.\nI hope this satisfies your inquiry. Please contact us if we can be of further assistance.\nSincerely,\nT. Glenn Foster\nChief, Regulatory Review and Reinvention Branch\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\n'Bened~ct~\n113.302DOTJRSPAIOHMS\nu.s. Deponment UNIT\nof Tronsponotlon ~llnder-5\n,Ipalln.and 1, AUG -I PM 3: 30\nH~~SMa.damS~ \"-01'15\nAdministration\nOffice of Hazardous Materials Standards\nJuly 25, 2011\nTo whom it may concern,\nMy inquiry today is in regard to compressed gas cylinders used for breathing enriched air (nitrox). The\nair in these cylinders will have elevated levels of 02 in the mixture of breathing gas ranging from 21% to\n1000..6 02 depending on the application. One commonly uses 3AL aluminum and 3AA steel cylinders for\nthis purpose. I have read the DOT Interpretation #06-0064. I wish to clarify the DOT position.\nMy questions are:\n1. 2. 3. At what 02 percentage must one clean a cylinder for 02 service when the cylinder is used for\nNitrox and must one conform to the cleanliness standards of 173.302?\nWhat is the maximum PSI of pressure can one put in the cylinder when charging the cylinder\nwith enriched air containing elevated levels of 02? Additionally, is this pressure maximum the\nsame for both aluminum and steel cylinders?\nMay one label a cylinder for enriched air (nitrox) if the cleanliness standards for 02 service have\n,notbeen met?\nrtnank you for your time and attention paid to my inquiry.\nJohn Fox\nNitroxFox LLC\nPO Box 32091\nSarasota, FL,34239","truncated":false,"body_characters":5208}