FMCSR 172.401 (Prohibited Labeling) Q&A for Drivers

No. A 172.401 citation will not result in an out-of-service order. Across our inspection records, zero out of 78 all-time 172.401 citations resulted in the vehicle being placed out of service, giving this code a 0.0% OOS rate. This is far below the national average of 31.4% across all FMCSR codes, meaning enforcement officers treat this as a documentation or labeling issue rather than an immediate safety threat that warrants removing the vehicle from operation.

No, 172.401 is one of the least serious hazmat labeling violations. While related codes like placarding violations (177.817(a)) see a 75.1% OOS rate and general loading/unloading hazmat violations (177.834A-HMC) hit 99.2% OOS, prohibited labeling stays at 0.0%. Even within the broader hazmat category, peer codes like 172.502(a)(1) hit 18.5% OOS and 172.516(c)(6) hits 1.6%, so 172.401 sits at the lower end of enforcement severity for hazmat document violations.

First, verify the labeling on your hazmat load is accurate and complete before your next dispatch. Second, check your vehicle for any other defects—our inspection records show that when 172.401 is cited, it often appears alongside mechanical issues like brake tubing defects, steering component wear, and lamp problems. Inspect your brakes, steering, lights, and medical certificate status. Third, document your corrective action and keep records of the fix in case of future audits. Unlike OOS violations, this is about getting compliance right, not emergency roadside repairs.

172.401 is rarely cited. Across 13 million+ roadside inspections, we see only 78 all-time citations for this code, ranking it #1497 out of 3,036 FMCSR codes by citation volume. In the last 12 months, there were just 14 citations nationwide, and only 2 in the last 90 days. This low volume suggests that most drivers and carriers handle hazmat labeling correctly, or that inspectors focus enforcement on more serious hazmat violations like placarding or loading defects.

Over the last 180 days, Texas led with 3 citations, followed by Iowa with 2 citations. No other state recorded citations during that period in our database. Both states saw 0.0% OOS rates on those citations. The low regional frequency reinforces that 172.401 is an uncommon violation, so being cited for it in these states puts you in a very small group.

Yes, you can dispute the citation through the FMCSA's DataQs (Record Dispute Resolution) portal. Since 172.401 involves labeling documentation, contestability depends on whether the inspector's finding was factually accurate. Gather photos, shipping paperwork, and any labels from the load to prove compliance at the time of inspection. If the inspector misidentified the hazmat classification or missed that proper labels were present, you have grounds to challenge. File within the DataQs timeline (typically within 90 days of citation) with supporting documentation.

Five carriers appear tied for the most 172.401 citations in our all-time records, each with 2 citations: HOT SHOT EXPRESS INC (USDOT 269495), FLEX-CHEM CORPORATION (USDOT 1726140), VENTURE DISTRIBUTORS CORP (USDOT 3141195), NICOM COATINGS LLC (USDOT 3821068), and MAXFLOW CHEMICALS OF TEXAS LLC (USDOT 2369876). The fact that no single carrier dominates suggests this is an isolated issue across multiple operators rather than a systematic compliance problem at one company.

Enforcement is very sporadic. Over the last 12 months, citations peaked in June 2025 with 5 citations, then dropped to 1 or 0 citations per month through early 2026. This unpredictable pattern reflects the rarity of the violation—there's no upward or downward trend, just occasional detections. Compliance risk is low and stable if you're handling hazmat labeling according to FMCSA rules.