What 172.302B means in plain language
When you transport hazardous materials in bulk containers—think large tanks or portable tanks on your truck—those containers must display specific markings to identify what's inside and communicate hazard information to emergency responders and other road users. FMCSR 172.302B requires that these markings meet precise sizing standards.
If an inspector cites you for 172.302B, it means your bulk package's marking—whether it's a placard, label, or other hazard communication—doesn't meet the minimum or maximum size requirements set by federal regulation. This isn't about where the marking is placed or what it says; it's specifically about the physical dimensions being out of spec.
For drivers and fleet managers, this is a marking compliance issue that's separate from the hazmat content itself. A marking that's too small might be hard to read; one that's too large might obstruct visibility or create practical handling problems.
What our enforcement data actually shows
Across our 13 million+ inspection records, 172.302B is a rare citation. All-time, we've recorded 14 citations. In the last 12 months, there have been just 2 citations, and in the last 90 days, 2 citations as well. Nationally, 172.302B ranks #2083 out of 3,036 FMCSR codes by citation volume.
Most importantly for your situation: none of the 14 all-time citations for 172.302B resulted in an out-of-service order. The OOS rate is 0.0%. This stands in sharp contrast to the all-FMCSR average OOS rate of 31.4%. Inspectors cite this violation, but they do not typically place trucks out of service for incorrect bulk package marking size. That means if you've been cited for 172.302B, you're unlikely to be sidelined immediately—though you must address the citation and correct the marking before your next inspection.
The enforcement trend shows 1 citation in February 2026 and 1 citation in March 2026, indicating sporadic rather than systematic enforcement pressure on this specific code.
Who gets cited most
Our inspection records show that Texas accounts for 2 citations in the last 180 days, with 0 out-of-service placements (0.0% OOS rate). The limited geographic data reflects the rarity of this citation overall—Texas is the only state in our top-state list for 172.302B enforcement in the past 180 days.
Looking at carriers across all-time records, fleets such as Transportacion Carretera SA de CV have been cited 4 times for this code, and Dan Williams Company 3 times. These carriers handle hazardous materials regularly, and marking compliance is part of their ongoing operations. The citation frequency does not indicate systemic negligence, only that bulk package marking precision is a detail that requires continuous attention in hazmat transport.
How severe is this compared to similar codes
172.302B sits in the Hazardous Materials category. When you compare it to related marking and placarding violations, the contrast is striking:
- 177.817(a) — Placarding violation: 2,274 citations all-time, 75.1% OOS rate. This is a much more serious infraction.
- 172.516(c)(6) — Placard damaged, deteriorated, or obscured: 1,796 citations all-time, 1.6% OOS rate. Similar low enforcement severity.
- 172.602(c)(1) — Maintenance/accessibility of Emergency Response information: 1,464 citations all-time, 0.0% OOS rate. Equally lenient in terms of OOS placement.
Your 172.302B citation is far less commonly enforced than broader placarding violations (177.817a) and carries zero out-of-service risk, making it a lower-tier compliance issue in the hazmat ecosystem.
How to avoid it
To prevent a 172.302B citation in the future, take these concrete steps:
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Verify marking dimensions before loading. Before you accept a bulk container, measure or visually inspect the hazard markings to confirm they meet federal sizing standards. If you're pulling a portable tank or working with a leased tank, don't assume the markings are correct just because the equipment arrived at your facility.
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Conduct a pre-trip hazmat-specific walk-around. Our data shows that 172.302B often co-occurs with cargo securement issues (393.110B and 393.104F4/R in recent inspections), suggesting that a thorough hazmat check overlaps with general load security. Look at your markings, tiedowns, and overall package condition in one pass.
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Replace or refresh faded or worn markings. If a marking is borderline on size—barely legible—don't wait. Hazmat marking maintenance falls under routine vehicle upkeep, and doing it proactively keeps you ahead of inspectors.
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Document your fleet's marking specifications. If you operate vehicles with bulk containers regularly (particularly if you drive a Kenworth or International, the two vehicle makes most commonly cited for this code in our records), maintain a reference guide showing what compliant marking sizes look like for your equipment. Share it with your team.
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Work with your dispatcher or hazmat coordinator. If your company operates multiple vehicles carrying bulk hazmat, build a simple audit routine—quarterly or semi-annually—where someone physically checks a sample of your markings for size compliance. This is especially important if your operation includes third-party or leased tank equipment.