What 172.313A means in plain language
When you transport hazardous materials, certain packages must display a label indicating whether the contents pose an inhalation hazard. This label serves as a critical warning to emergency responders, handlers, and other drivers about the specific risks the cargo presents.
Code 172.313A enforces the requirement that packages containing materials with inhalation hazards must be properly marked. If inspectors find a package that should carry this designation but doesn't, or if the labeling is incorrect or missing, you get cited. The label isn't optional—it's part of the comprehensive hazmat communication system that keeps the entire supply chain safe.
What our enforcement data actually shows
Across our 13 million+ inspection records, 172.313A is exceptionally rare. We've recorded just 1 citation all-time for this violation, with 0 citations in the last 12 months and 0 in the last 90 days. This code ranks #2796 out of 3,036 FMCSR violations by citation volume.
When this violation does occur, it carries serious consequences. The single citation in our database resulted in an out-of-service placement, giving this code a 100.0% out-of-service rate. For context, the all-FMCSR average OOS rate is 31.4%, so this violation—when cited—is treated as a critical safety issue with zero tolerance for road operation.
The rarity of this citation doesn't mean it's unimportant. It suggests that most carriers and drivers are already complying well with inhalation hazard labeling requirements, but when inspectors do find a violation, enforcement is swift and absolute.
Who gets cited most
Our records show one carrier cited for this violation: Greenwood Motor Lines Inc (USDOT 63391) with 1 citation. The small enforcement volume makes state-by-state or carrier-by-carrier trend analysis impractical—this violation is simply not common enough to establish meaningful geographic or fleet patterns in the data.
How severe is this compared to similar codes
Inhalation hazard labeling sits within the broader hazardous materials compliance framework. Related violations show the spectrum of hazmat enforcement severity.
General loading and unloading violations (177.834A-HMC and 177.834(a)) are far more commonly cited—with 3,954 and 3,839 citations respectively—and both carry OOS rates above 97%, indicating they're treated as critical safety breaches. Placarding violations (177.817(a)) total 2,274 citations with a 75.1% OOS rate. By contrast, damaged or obscured placard violations (172.516(c)(6)) account for 1,796 citations but generate only a 1.6% OOS rate, suggesting inspectors distinguish between missing information and degraded labels.
172.313A's 100.0% OOS rate places it among the most serious hazmat violations—comparable in severity to general loading/unloading failures but far rarer in occurrence, suggesting inspectors cite it only when the violation is unambiguous and serious.
How to avoid it
Because this violation is about package-level labeling before your cargo even reaches your truck, prevention starts with thorough pre-transport verification:
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Request hazmat documentation from your shipper before loading. Verify that every package destined for your vehicle has been labeled according to hazmat regulations, including any required inhalation hazard designations. Don't accept packages with missing, faded, or illegible labels.
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Inspect every hazmat package during pre-trip. Walk the load and confirm labels are legible, properly affixed, and undamaged. If you spot a package without required markings or with damaged labeling, refuse it and document the issue.
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Confirm your understanding of what constitutes an inhalation hazard. Not every chemical is classified as an inhalation hazard, but those that are must be labeled. If you're uncertain about your cargo's classification, ask your dispatcher or the shipper's hazmat coordinator before leaving the facility.
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Keep your hazmat placard and packaging inspection sharp. The fact that this violation results in 100% out-of-service enforcement means roadside inspectors take labeling violations extremely seriously. A moment of verification before departure can prevent a citation that stops your entire load.
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Document shipper compliance at pickup. Note the condition and completeness of hazmat labeling when you accept the load. This creates a record that the violation didn't originate with you or your carrier.