# Atlantic Research Corporation — Hazardous Materials Safety Interpretation **Citation:** 01-0095 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2001-05-22 01-0095 response to Atlantic Research Corporation concerning 172.101. ## Document text <<>> of Transportation U.S. Department 400 Seventh Street. S.W. Washington, D.C. 20590 Research and Special Programs Administration MAY 2 2 2001 Mr. Aaron Greso Ref. No. 01-0095 Atlantic Research Corporation 5945 Wellington Road Gainesville, Virginia 20166-1699 Dear Mr. Greso: This responds to your April 17, 2001 letter requesting clarification on the correct classification of your mixture under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask for the correct classification of a mixture of silver nitrate and potassium nitrate, each of which is classed as a Division 5.1 material. Your understanding that a "new" material must be tested as a Class 1 explosive using the "Card Gap" test under the UN Manual of Tests and Criteria is incorrect. Such a test is required only where other information indicates the material could have explosive properties. Under the HMR, it is the shipper's responsibility to determine the hazard class of the material to be transported. This Office does not perform that function. In making this determination, you must consider the characteristics of the entire mixture rather than its individual components. Based on the test results and information provided in your letter, it is the opinion of this Office that the mixture of silver nitrate and potassium nitrate should be classed according to the Division 5.1 packing group criteria in § 173.127 of the HMR. I hope this answers your inquiry. Sincerely, Transportation Regulations Specialist Office of Hazardous Materials Standards 010095 17210) <<>> a unil of Sequa Corporation Atlantle Rosearch Carparution 172:16.1 Gainesville, Virginia 20166-1689 6946 Wellington Road 703 754-5000 April 17, 2001 CIA SEQUA fication 01-0095 Director for the Office of Hazardous Material Standards U.S. Department of Transportation RSPA (DHM10) Washington DC 20590-0001 FX 202 366-3012 Dear Mr. Mazzullo, I am writing to you to request an interpretation of the standards as applied to a mixture of already classified materials. We are planning to make a mixture of silver nitrate (AgN) and potassium nitrate (KN). Each is already However, according to the UN "Orange book", Transport of Dangerous Goods, Manual of Tests and Criteria, all "new" materials should be tested as a Class 1 explosive in a "Card Gap" test. This requirement, for this material, is somewhat puzzling. When this material is placed upon a hot plate, using a DSC (differential scanning calorimeter), the material shows no exotherm until exceeding 400 °C-after operating in the area of 400 °C, the material bubbles and boils away—without a flame. When investigated which temperature, the exother could represent the decomposition of silver nitrate. (Decomposition temperature of AgN is 444 C; KN melts at 334 °C, AgN melts at 212 °C.) >8 Kg @ 50 cm; 2) "Friction" >1800 psi @ 90°, and 3) "ESD" >6 Joules. [All three tests showing 10 In addition, the material passes all of the following material hazards at the highest settings: 1) "Drop weight' subsequent negative results for each test]. possible to interpret this material as not being a Class 1 material? Since the material will not bum by itself, nor will it ignite when physically manipulated in a rigorous manner, is it I would like to classify this material as a 5.1 Class Il, simply because silver nitrate, the most hazardous material in the mixture, is classified as 5.1 Class II. Can the test results, listed above, be interpreted as indicating that the material is not a Class 1.x material? I would prefer not to have to ship off site, an expensive, used, unburned material, recovered from a card-gap rest, for recycling. Thank you for any help you can give. FX 703 754 5346 [1] K. Meszaros Szocsenyi, K. Tomor, and G. Pokol; J. Thermal Analysis, 11 (1884) 125-134 High techrukuzy lendorghip since 1948 ARC TOTAL P. 01 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `2114a15ca853597267b8b9156a6b0814d10f2bcd951d03d37da5c927fad1801c` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T05:47:40.093Z - Document slug: `phmsa-interpretation-01-0095` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Atlantic Research Corporation" ], "individuals": [ "Mr. Aaron Greso" ], "refIds": [ "01-0095" ], "catalogDates": [ "2001-05-22" ], "catalogParts": [ 172 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/55361" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "172.101", "173.127" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/172101" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2001/010095.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2001/010095.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2001/010095.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/01-0095-2f7eafd710.pdf", "pdfArtifactSha256": "deca260460f97086353fdaf83816abde884980b93d8f437ff3dd22692016852f", "extractedTextPath": "data/sources/phmsa-interpretations/01-0095-2f7eafd710.v2.txt", "extractedTextSha256": "08d2308a121ef51f33d9552c02938ef7e8bf0002193b226786a2a928a07cfb5c", "pageCount": 2, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```