FMCSR 172.325B: Improperly Marked Molten Aluminum or Sulfur

No. Across our 13 million inspection records, 172.325B citations have never resulted in an out-of-service order. The OOS rate is 0.0%—all 3 all-time citations in our database resulted in violations only, with no vehicles removed from service. This is far below the 31.4% national average OOS rate across all FMCSR codes, meaning this violation is treated as a compliance notice rather than an immediate safety stand-down.

No, it's among the least serious hazmat violations. Our records show 172.325B ranks #2551 out of 3,036 FMCSR codes by citation volume. Compare this to peer hazmat codes: general loading violations (177.834A) carry a 99.2% OOS rate, and placarding violations (177.817) range from 75.1% to 5.2% OOS depending on type. With a 0.0% OOS rate, 172.325B is in the lowest-enforcement tier—typically a documentation or marking correction issue, not a structural safety defect.

First: photograph or document the marking condition cited. Second: verify your hazmat shipper documentation matches the marking requirement for molten aluminum or molten sulfur. Third: if you're carrying hazmat and other violations were found, address those immediately—our data shows 172.325B inspections commonly co-occur with brake system issues (393.45B2PC), tire defects (393.75A4), fuel leaks (396.5B), and maintenance violations (396.3A1). Fourth: contact your carrier's hazmat compliance officer and request a re-inspection after correcting the marking.

Very rarely. Across 13 million inspections in our database, we've seen only 3 all-time citations for 172.325B, with 2 in the last 12 months and 2 in the last 90 days. Both recent citations occurred in Texas. This low frequency means you're unlikely to encounter this violation unless you're transporting molten aluminum or molten sulfur—and even then, proper marking compliance is straightforward.

Yes. If you believe the marking was compliant at the time of inspection, or if the inspector misidentified your cargo, you can submit a DataQS (Roadside Data Quality Service) request to contest the citation. DataQS allows drivers and carriers to challenge inspection findings on grounds of factual accuracy. For a marking violation like 172.325B, gather photos, shipper paperwork, and any placarding or hazmat documentation from that date, then file through FMCSA's DataQS portal. Success depends on documentary evidence that the marking met FMCSR requirements.

Almost exclusively in Texas. Our records show 2 citations in Texas over the last 180 days—the only state data available. This concentration likely reflects border-zone hazmat traffic and specialized chemical transport routes. If you operate in other regions, the risk of this citation is minimal. If you haul molten materials through Texas, focus on marking compliance before crossing state lines.

Citations are extremely infrequent and stable. In the last 12 months, we recorded only 2 citations for 172.325B—both in February 2026. The code is not trending higher or lower because the absolute volume is so low (3 all-time). This suggests either very few carriers haul molten aluminum or molten sulfur, or the industry maintains strong compliance. Either way, you're unlikely to see this violation unless you operate in specialized hazmat transport.

When 172.325B is cited, inspectors often find unrelated equipment and maintenance issues in the same inspection. Our 90-day data shows co-occurring violations include hazmat packaging residue (173.24B4), driver language proficiency at border zones (391.11B2-Z), brake tubing damage (393.45B2PC), window obstruction (393.60E-WS), tire cuts (393.75A4), and fuel system leaks (396.5B). This pattern suggests that when hazmat marking issues surface, the vehicle typically needs broader mechanical inspection. Address any secondary violations cited in the same inspection report immediately.