Interpretation Response #25-0055
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Commercial Vehicle Safety Alliance
Individual Name: Collin B. Mooney
Location State: DC Country: US
View the Interpretation Document
Response text:
September 22, 2025
Collin B. Mooney, MPA, CAE
Executive Director
Commercial Vehicle Safety Alliance
99 M Street, SE, Suite 1025
Washington, DC 20003
Reference No. 25-0055
Dear Mr. Mooney:
This letter is in response to your email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to recent changes to the HMR regarding reduced-size combustible placards on intermediate bulk containers (IBCs) and portable tanks (see § 172.514(c)(1) and (c)(4)). You state that your organization has identified several issues regarding the changes made to this section and is requesting clarification on their scope and intent.
We have paraphrased and answered your questions as follows:
Q1. Would it be acceptable to use a reduced-size placard that is not the exact same size as a label, but between the size of a label and a placard?
A1. Yes. Paragraphs (c)(1) and (c)(4) in § 172.514 state that portable tanks and IBCs containing combustible liquids may be placarded with a combustible placard that meets the label specifications for size in § 172.407(c). That section states that each label must be at least (emphasis added) 100 mm (3.9 inches) on each side. This provision allows labels to be more than 100 mm on each side. Therefore, a smaller sized placard that meets the labeling provision in § 172.407(c) complies with the requirements in the HMR.
Q2. You note that the HM-219D final rule did not address the size requirements for United Nations (UN) identification numbers on reduced sized placards. You ask if it is acceptable to use a combustible placard with the UN identification number printed on it as the reduced-size placard.
A2. Yes, as noted in A1, § 172.514(c)(1) and (c)(4) allow the use of a reduced-size placard that meets the label size specifications (emphasis added) in 49 CFR § 172.407(c). This provision permits placards that otherwise conform to all applicable parts of the HMR to be reduced in size, based on the reasoning that labels were already permitted as an alternative to placards on portable tanks with a capacity of less than 1,000 gallons and IBCs.
Q3. You note that HMR does not include a combustible liquid label and that a reduced-size combustible placard could be the same size as a label, potentially leading to incorrectly cited roadside violations and unnecessary shipment delays. You ask why PHMSA did not authorize a combustible label, with label specifications, into the regulations for IBCs and portable tanks.
A3. In accordance with § 173.150(f)(2), the HMR does not apply to a material classed as a combustible liquid in a non-bulk packaging unless the combustible liquid is a hazardous substance, a hazardous waste, or a marine pollutant. This means that, in many cases, combustible liquids are only subject to HMR requirements when in bulk packaging, which typically require placards rather than labels. The use of the term "placard" was purposeful to avoid confusion between requirements for bulk packaging and those for non-bulk packaging.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Alexander Wolcott
Acting Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
§ 172.407(c), § 172.514(c)(1), § 172.514(c)(4), § 173.150(f)(2)