# MST2 USCG Sector LA-LB, Facilities Branch — Hazardous Materials Safety Interpretation **Citation:** 10-0037 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2010-03-30 10-0037 response to MST2 USCG Sector LA-LB, Facilities Branch concerning 172.313. ## Document text <<>> U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration MAR 3a 2010 1200 New Jersey Ave, SE Washington, D.C. 20590 Christopher H. Smith, MST2 USCG Sector LA-LB, Facilities Branch 1001 South Seaside Avenue San Pedro, CA 90731 Ref. No. 10-0037 Dear Mr. Smith: This responds to your February 3, 2010 request for interpretation of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask if the marking requirements for poison-inhalation-hazard (PIH) materials in § 172.313(a) apply to both non-bulk and bulk packages. Section 172.313(a) requires packages and transport vehicles containing PIH materials to be marked with the words "Inhalation Hazard" in association with the required labels or placards, as appropriate, and shipping name when required. This requirement applies to both non-bulk and bulk packages. The marking must be on two opposing sides of a bulk package. When the words "Inhalation Hazard" appear on the label, as prescribed in §§ 172.416 and 172.429, or placard, as prescribed in §§ 172.540 and 172.555, the "Inhalation Hazard" marking is not required on the package. Section 17L23(b)(10)(iv)(A), which you also reference in your letter, applies to shipments of PIH materials transported under the IMDG Code. When packages ofPIH materials are transported in a closed transport vehicle or freight container, a label or placard conforming to the IMDG Code specifications for a "Class 2.3" or "Class 6.1" label or placard may be substituted for the POISON GAS or POISON INHALATION HAZARD label or placard, as appropriate. The transport vehicle or freight container containing such packages must be placarded with a POISON GAS or POISON INHALATION HAZARD placed, as appropriate. Additionally, the transport vehicle or freight container must be marked with the identification number for the hazardous material, regardless of the total quantity contained in the transport vehicle or freight container, in a manner specified in §172.313( c) of the HMR. I hope this answers your inquiry. If you need additional assistance, please contact this Office. Sincere~, ,-iJ d_/ at-A~~ Chief, Standards Development 'U' ~.[cn.v of Hazardous Materials Standards <<>> -SODth e. . ) /J.) 23f7/.23(~)(/O)(IV 0 ~112.3!3 (CJ --Pa..c ka.aes , Carolyn, J ~ 0 Attached is a written request for interpretation of the regulations. N -()031 Thanks, Rob -----Original Message----From: Christopher.H.Smith@uscg.mil [mailto:Christopher.H.Smith@uscg.mil] Sent: Wednesday, February 03, 2010 2:56 PM To: INFOCNTR (PHMSA) Cc: Collet, Michael LTJG Subject: ATTN: Edward Mazzullo Good Afternoon Sir, I need a legal interpretation of a couple of cites in the 49CFR, in particular the following: Q9CFR172.12s(b)(10)(iv)(A)-----corrected section 49CFR 171.23(b)(10)(iv)(A) 49CFR 172.313(a) My question is does the entire paragraph of 49CFR 172.313(a) apply to Non-bulk lpackages of hazmat? If so, referring back to 49CFR 172.12s corrected section 171.23(b)(10)(iv)(A), the last sentence in that paragraph states that packages must meet the placarding requirements of 172 which would require a material "poisonous by inhalation" to placard with a poison by inhalation placard. The last sentence of 49CFR 172.313(a) states that if the words poison by inhalation appear on the label or placard then the marking required by 49CFR 172.313(a) is not needed. In short, I need to know the applicability of 49CFR 172.313(a), does it, in its entirety, apply to both non-bulk and bulk packages. Thank you for your help in this matter. Very Respectfully, Christopher H. Smith, MST2 USCG Sector LA-LB, Facilities Branch Office: (310) 521-3745 Fax: (310) 521-3763 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `c346ad5f588c72d2bf116f793270c523ec2c0175945ac3f9a58eb6ac41917d37` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T00:01:57.386Z - Document slug: `phmsa-interpretation-10-0037` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "MST2 USCG Sector LA-LB, Facilities Branch" ], "individuals": [ "Christopher H. 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