FMCSR 172.402A: No Label for Subsidiary Hazard — Q&A

No. Across our inspection records, 172.402A has never resulted in an out-of-service citation—the OOS rate is 0.0%. Of 23 all-time citations for this code in our database, all 23 were issued without placing the vehicle out of service. For context, the average OOS rate across all FMCSR codes is 31.4%, so this violation carries significantly lower enforcement severity than most other hazmat or equipment violations.

172.402A is among the least-enforced hazmat codes. It ranks #1881 out of 3,036 FMCSR codes by citation volume, with only 23 all-time citations. By contrast, peer hazmat codes show much higher enforcement: 177.834A-HMC has 3,954 citations with a 99.2% OOS rate, and 177.817(a) has 2,274 citations with 75.1% OOS. Even among placarding violations, 172.402A appears rarely—172.516(c)(6) has 1,796 citations. The low frequency and zero OOS rate indicate inspectors cite this infrequently and treat it as a documentation matter rather than an immediate safety threat.

First, confirm the subsidiary hazard label is present and readable on your load documentation and packaging. When we see 172.402A citations in the same inspections as other violations, they most often co-occur with 172.332A (hazmat class/division ID missing), 172.504A (placarding table 1 materials), and 177.817A (general placarding violations). Check that all hazmat labeling—primary and secondary—matches your shipping papers and vehicle placards. If placards are damaged or deteriorated, repair or replace them. Document the correction and maintain records of the fix.

In the last 180 days, Texas is the only state in our top enforcement list with 6 citations and a 0.0% OOS rate. Over the full dataset, Texas also dominates, accounting for roughly 26% of all 172.402A citations. The extremely low national volume (15 citations in the last 12 months) means this code is enforced sporadically and appears concentrated in Texas. If you operate in Texas and carry hazmat with subsidiary labels, heightened attention to label completeness is warranted.

Citation frequency remains very low and sporadic. In the last 12 months, we recorded 15 citations across all states, with no clear upward or downward trend. June 2025 saw a spike of 5 citations; other months ranged from 1 to 2. This suggests the violation is either rare in practice or enforcement is episodic rather than systematic. The 90-day volume is just 2 citations, indicating either recent compliance improvement or continued low inspection focus on this particular issue.

Across our database, MAXFLOW CHEMICALS OF TEXAS LLC (USDOT 2369876) accounts for 4 of the 23 all-time citations—roughly 17% of all 172.402A violations recorded. The remaining carriers each have 1 citation. This concentration suggests the violation may reflect carrier-specific labeling procedures or exposure (e.g., chemical transport). Other carriers cited once include Old Dominion Freight Line, Southwestern Motor Transport, and several smaller hazmat carriers, indicating the violation is not limited to a single industry segment.

Yes, you can submit a DataQs (Databus Quality Services) challenge if you believe the citation is factually inaccurate or based on a misinterpretation of the regulation. Since 172.402A is a documentation and labeling violation—not an equipment defect—the core question is whether your load actually was missing the required subsidiary hazard label. DataQs disputes work best when you have shipping papers, invoices, or photos showing the label was present. File the challenge through your carrier's FMCSA account within 90 days of the citation. Success rates depend on the strength of your evidence.

Both. 172.402A citations are recorded against both the driver and the motor carrier in the FMCSA's safety database. The violation appears in the carrier's BASIC (Behavior Analysis and Safety Improvement Categories) safety profile and in the driver's record. This means repeated citations can affect your carrier's CSA scores and your own hire-ability or insurance profile. If you were cited for missing or illegible subsidiary labels, your carrier may require retraining or procedural changes to prevent future violations.