What 172.322B means in plain language
When you transport hazardous materials in bulk packaging, the shipment must carry a MARPOL marking. MARPOL refers to the International Convention for the Prevention of Pollution from Ships—a set of rules that identify materials subject to maritime transport restrictions.
Bulk packaging means a containment system with a capacity of 450 liters or more. If you're hauling hazmat in a tank truck, cargo tank, portable tank, or similar large vessel, that container must display the required MARPOL identifier. The marking tells inspectors and emergency responders that the cargo is subject to marine pollution prevention rules and must be handled according to those standards. Without it, regulators can't quickly determine shipment restrictions, and you're non-compliant.
What our enforcement data actually shows
Across our inspection database of 13 million records, 172.322B is rarely cited: just 4 all-time citations, with 3 occurring in the last 12 months and all 3 in the last 90 days. The citation received 0 out-of-service placements across all inspections in our database, yielding a 0.0% OOS rate—markedly lower than the all-FMCSR average OOS rate of 31.4%.
This violation ranks #2480 out of 3,036 FMCSR codes by citation volume, making it exceptionally uncommon. The rarity reflects that most hazmat carriers are well aware of international maritime requirements and mark their bulk packages accordingly. When it does occur, inspectors typically issue a citation but do not remove the vehicle from service, suggesting regulators view it as a labeling deficiency rather than an immediate safety threat.
Who gets cited most
Our inspection records show citations concentrated in two states over the last 180 days: Texas with 2 citations (0.0% OOS rate) and Illinois with 1 citation (0.0% OOS rate). All citations resulted in zero out-of-service placements, consistent with the national pattern.
Looking at all-time data, four carriers appear in our records with a single citation each: New Prime Inc (USDOT 3706), North American Bulk Transport Inc (USDOT 125432), Southern Energy Transportation Inc (USDOT 1373460), and A&A Benitez Trucking LLC (USDOT 3413173). These data points represent isolated incidents, not patterns indicative of systemic compliance issues.
How severe is this compared to similar codes
172.322B sits in the broader hazardous materials category alongside codes that carry much higher enforcement and OOS rates. For comparison, peer violations in the same regulatory domain show striking differences:
- 177.834A-HMC (General loading/unloading hazmat) has logged 3,954 citations with a 99.2% OOS rate—indicating that general hazmat loading errors commonly result in vehicle removal.
- 177.817(a) (Placarding violation) has 2,274 citations with a 75.1% OOS rate—much more serious than a missing MARPOL mark alone.
- 172.516(c)(6) (Placard damaged, deteriorated, or obscured) has 1,796 citations with only a 1.6% OOS rate, which is more comparable to 172.322B in severity.
The near-zero OOS rate for 172.322B reflects that a missing MARPOL marking is treated as a documentation/identification gap rather than a structural or operational safety failure like improperly loaded cargo or missing placards altogether.
How to avoid it
To prevent a 172.322B citation on your next hazmat shipment, implement these driver-focused checks:
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Verify MARPOL marking before accepting the load. Before you hook up to any bulk tank or portable tank, confirm the container displays the required MARPOL identifier. Do not depart if it's missing. Contact the shipper or your dispatcher immediately—this is not your responsibility to apply, but it is your responsibility to verify.
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Know what MARPOL marking looks like. The identifier typically appears as a label or placard on the tank exterior and denotes whether the contents fall under MARPOL Annex I (oils), II (noxious liquids), III (harmful substances), V (garbage), or VI (air pollutants). Review photos or samples with your safety team so you can spot it at a glance.
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Cross-check your bill of lading. Your shipping documents should explicitly state if the hazmat is subject to MARPOL. If the bill says "MARPOL regulated" and the tank is blank, halt the load and report it. Our data shows that co-occurring violations include missing hazmat class/division ID numbers (172.332A), suggesting that MARPOL marking gaps often accompany other ID deficiencies—a pattern that suggests systemic paperwork or labeling gaps in the load preparation process.
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Inspect the tank exterior during pre-trip. Examine the tank surface for any missing, faded, or damaged marking. Because deteriorated placards co-occur with this code in our data (177.817E), make sure all external identifiers are legible and securely affixed.
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Communicate with your fleet's hazmat coordinator. If you handle bulk hazmat regularly, ask your safety team to brief you on MARPOL requirements and the specific shipment profiles you're most likely to encounter. A 5-minute pre-shift conversation can eliminate this citation entirely.
The 0% out-of-service rate for this code is good news: you won't be pulled off the road. But a citation still damages your CSA scores and triggers additional scrutiny at your next inspection. Prevention is far easier than remediation.