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

No. Across our 13 million inspection records, the 0.0% out-of-service rate for 172.402(a) citations means your truck will not be placed out of service for this violation. Of the 32 all-time citations in our database, all 32 resulted in non-OOS findings. This stands in stark contrast to the 31.4% average OOS rate across all FMCSR codes—making this one of the most lenient citations in hazmat enforcement.

No, this is among the least serious hazmat violations we track. In our inspection records, 172.402(a) ranks #1775 out of 3,036 FMCSR codes by citation volume, with only 32 all-time citations and zero citations in the last 90 days. Compare this to peer hazmat codes like 177.834A (3,954 citations, 99.2% OOS rate) or 177.817(a) (2,274 citations, 75.1% OOS rate). The absence of enforcement activity and zero OOS outcomes indicate inspectors view this as a minor labeling documentation issue rather than an operational safety concern.

Immediate steps:

1. Photograph the hazmat package and shipping documentation to preserve the citation record
2. Contact your dispatcher or hazmat coordinator to confirm the subsidiary hazard classification
3. Verify that the required subsidiary hazard label is present and legible on the transport unit
4. Request the inspection report from the roadside officer to understand exactly which package or label was cited
5. If the label was present but obscured or damaged, document corrective action (replacement label, verification)
6. File for DataQs review if you believe the citation was issued in error or the label was compliant at time of inspection

Enforcement of 172.402(a) is extremely rare. Our inspection database shows zero citations in the last 90 days and zero in the last 12 months. The only 32 all-time citations span multiple years, suggesting this violation is seldom cited or may reflect a very specific hazmat transport subset. If you operate a hazmat carrier, the probability of encountering this violation in routine roadside inspections is minimal compared to placarding violations (177.817(a): 2,274 citations) or general loading violations (177.834A: 3,954 citations).

Yes. You can file a Data Quality and Safety (DataQs) challenge with FMCSA if you believe the citation was issued in error or if the violation was not present at the time of inspection. For a labeling violation like 172.402(a), focus your challenge on documentation: submit photos, shipping papers, or inspection photos proving the subsidiary hazard label was present, legible, and compliant. FMCSA reviews DataQs challenges and can remove or correct citations if evidence supports your claim. The process typically takes 30–45 days.

Across our 13 million inspection records, Imperative Chemical Partners Inc (USDOT 1796904) leads with 3 citations for 172.402(a). Four carriers—American Welding & Gas Inc, Acme Truck Line Inc, Chem Tech Services Inc, and Pro Ject Chemicals LLC—each had 2 citations. The remaining carriers in the database had 1 citation each. All citations are hazmat or specialty chemical transporters, indicating this violation is isolated to carriers moving regulated hazardous materials.

Yes, significantly. Our inspection records show 172.402(a) has a 0.0% OOS rate versus 75.1% for 177.817(a) (placarding violation) and 5.2% for 177.817(e) (placard deteriorated/damaged). Even 172.502(a)(1), the general placarding requirements code, carries an 18.5% OOS rate. The fact that zero of the 32 172.402(a) citations resulted in out-of-service orders suggests inspectors treat missing subsidiary hazard labels as administrative violations rather than imminent hazards warranting truck immobilization.

Across our database, Ford vehicles were cited 3 times for 172.402(a), while Freightliner, International, Peterbilt, Hino, and other common trucking makes each recorded 2 citations. One each of Kenworth, Chevrolet, Peterbilt, and Dodge appear in the data. The small sample size (32 total citations) reflects the rarity of this violation rather than a vehicle-brand pattern. No single make dominates 172.402(a) enforcement.