{"operation":"document","citation":"25-0017","title":"Teledyne Scientific & Imaging — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2025-04-08","effective_on":null,"summary":"25-0017 response to Teledyne Scientific & Imaging concerning 172.101, 173.22.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0017.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0017.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0017","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-04/250017.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nApril 8, 2025\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nJennifer Kuo\nTeledyne Scientific & Imaging\n1049 Camino Dos Rios\nThousand Oaks, CA 91360\nReference No. 25-0017\nDear Ms. Kuo:\nThis letter is in response to your February 11, 2025 email requesting clarification of the\nHazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the use of the\nUnited Nations (UN) identification number and proper shipping name “UN1396, Aluminum\npowder, uncoated.” Specifically, you ask if there is a particle size limit with respect to the use of\nthis hazardous materials description.\nNo. While certain hazardous materials descriptions and proper shipping names in the § 172.101\nHazardous Materials Table (HMT) limit use of the entry (e.g., a concentration range, particle\nsize, energy capacity, etc.), the entry for “UN1396, Aluminum powder, uncoated” does not\nspecify limiting criteria for particle size. Furthermore, the test method in the UN Manual of\nTests and Criteria do not specify a particle size. Hazardous materials that may be dangerous\nwhen wet, such as aluminum powder, uncoated, are classified based on the results of testing\n(i.e., UN Test N.5, Test method for substances which in contact with water emit flammable\ngases, see Section 33.5 of the UN Manual of Tests and Criteria) irrespective of particle size.\nUltimately, as provided in § 173.22, it is the shipper’s responsibility to properly classify and\ndescribe a hazardous material based on the classification criteria provided in the HMR.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nDirk Der Kinderen\nChief, Standards Development Branch\nStandards and Rulemaking Division\n\n<<<PAGE 2>>>\n\nCasey\n25-0017\nFrom: INFOCNTR (PHMSA)\nTo: Dodd, Alice (PHMSA)\nCc: Hazmat Interps\nSubject: FW: Request for letter of interpretation\nDate: Wednesday, February 12, 2025 12:02:33 PM\nGood afternoon Alice,\nSee the attached interpretation request. Let us know if you need anything else.\nBest,\nAminah\nFrom: Kuo, Jennifer (US) <Jennifer.Kuo@Teledyne.com>\nSent: Tuesday, February 11, 2025 3:59 PM\nTo: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>\nSubject: Request for letter of interpretation\nYou don't often get email from jennifer.kuo@teledyne.com. Learn why this is important\nCAUTION: This email originated from outside of the Department of Transportation (DOT). Do\nnot click on links or open attachments unless you recognize the sender and know the content\nis safe.\nHello,\nI would like to request a letter of interpretation on the specific description of UN 1396,\nAluminum powder, uncoated. I am looking for the particle size that this UN number covers.\nSpecifically, I would like to know how large a particle is considered a powder with respect to\nthis UN designation. I have not been able to find the particle size defined for this particular\nchemical.\nPlease send the information to:\nJennifer Kuo\nTeledyne Scientific\n1049 Camino Dos Rios\nThousand Oaks, CA 91360\n(805)373-4536\nJennifer.Kuo@teledyne.com\nPlease let me know if you have questions on my request.\nThank you,\nJennifer Kuo\n\n<<<PAGE 3>>>\n\nJennifer.Kuo@teledyne.com\n(805)373-4536\nTeledyne Scientific & Imaging\nTeledyne Confidential; Commercially Sensitive Business Data","truncated":false,"body_characters":3345}