What 172.313A-HMMS means in plain language
When you transport hazardous materials, every package must carry specific markings to tell emergency responders and handlers what's inside. An inhalation hazard marking is one of those critical labels—it alerts people that the substance inside can cause serious harm if inhaled.
Violation 172.313A-HMMS is issued when a hazmat package is offered for transport without the required inhalation hazard marking. This isn't about a marking being faded or hard to read—this is about the marking being absent altogether. From a compliance standpoint, it means the shipper or carrier put a hazmat package into the supply chain without proper warning labels.
The practical consequence: if your vehicle is stopped at roadside inspection and inspectors find a hazmat package lacking this marking, you'll be cited. The marking requirement exists because emergency responders rely on these labels to make life-or-death decisions during an incident.
What our enforcement data actually shows
Across 13 million inspections in our database, this specific violation is rare. Our inspection records show only 2 all-time citations for 172.313A-HMMS, with 2 citations in the last 12 months and 0 in the last 90 days. Neither citation resulted in an out-of-service order—the OOS rate is 0.0%.
This code ranks #2651 of 3,036 FMCSR codes by citation volume, placing it well below the all-FMCSR average OOS rate of 31.4%. The rarity of enforcement doesn't mean you can ignore it; it reflects the fact that most hazmat shippers and carriers get this requirement right. When violations do occur, they're typically caught and corrected without placing the vehicle out of service.
Data from our records shows citations occurred in May 2025 and August 2025, each resulting in no out-of-service placement.
Who gets cited most
Our inspection records show only two carriers with citations for this violation: Transport Express Inc (USDOT 30274) with 1 citation and Reis Trucking Inc (USDOT 228741) with 1 citation. The vehicle makes involved were MTCI, Peterbilt, Polar Mfg., and PTRB—no pattern emerges from such a small enforcement volume.
Because only 2 citations exist in our 13 million-record database, state-level analysis would be meaningless. The violation is not concentrated geographically or by carrier type.
How severe is this compared to similar codes
Hazmat marking and placarding violations span a wide severity spectrum. Our data shows that general loading and unloading hazmat violations—codes 177.834A-HMC and 177.834(a)—are far more common (3,954 and 3,839 citations respectively) and result in out-of-service rates of 99.2% and 97.9%. Those violations involve actual unsafe handling of hazmat cargo.
Placarding violations under 177.817(a) occur 2,274 times in our records with a 75.1% OOS rate, reflecting the serious nature of missing or incorrect placards on the vehicle exterior. By contrast, 172.313A-HMMS focuses on package-level markings and has generated minimal enforcement action.
Code 172.602(c)(1)—maintenance and accessibility of Emergency Response information—shares 172.313A-HMMS's 0.0% OOS rate despite 1,464 all-time citations, suggesting that marking and labeling deficiencies, while cited, rarely warrant immediate vehicle removal from service.
How to avoid it
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Before accepting a hazmat shipment: verify that every package bears the required inhalation hazard marking before loading. If the shipper's paperwork and placards don't match the actual markings on boxes or containers, refuse the load and report the discrepancy.
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Know your cargo: familiarize yourself with the hazard class of materials you typically haul. Inhalation hazards include gases, dusts, and aerosols that pose respiratory risk; shippers must mark these explicitly. If you're unsure whether a substance requires this marking, check the shipping papers and ask the shipper.
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Inspect during pre-trip: walk around your loaded vehicle before departure and spot-check visible hazmat packages for presence and legibility of all required markings. Don't assume the shipper got it right.
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Document compliance: photograph or note the presence of markings on high-visibility hazmat loads. If you're stopped at inspection and can show you verified markings at load-out, you have evidence you didn't knowingly transport unmarked cargo.
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Communicate with your dispatcher: if you receive a load with missing or questionable markings, report it immediately rather than delaying. Hauling it anyway, even for a short distance, puts you at citation risk.