FMCSR 172.402(b): Class Number Label Display – Q&A

No. Across our 13 million inspection records, this citation has never resulted in an out-of-service order. The out-of-service rate for 172.402(b) is 0.0%—all 6 all-time citations in our database resulted in warnings or citations only, not vehicle placement.

This contrasts sharply with the 31.4% average OOS rate across all FMCSR codes. You will not be sidelined immediately, but you must still correct the violation.

172.402(b) is extremely rare. Our records show only 6 all-time citations and zero citations in the last 12 months. By volume, it ranks #2357 of 3,036 FMCSR codes.

Related hazmat labeling violations are far more common: placarding general requirements (172.502) has 1,820 citations with an 18.5% OOS rate, and placard deterioration (172.516) has 1,796 citations with a 1.6% OOS rate. Class number label display is a low-frequency finding.

1. Photograph the cited vehicle and label location for your records.
2. Review the label on the hazmat package or container—ensure the class number is clearly displayed, readable, and properly positioned.
3. Document the correction with photos after repair.
4. Contact your carrier's hazmat compliance team if you're a driver; if you manage a fleet, initiate a label audit across your fleet.
5. Retain all inspection paperwork for DataQs review if you plan to contest.
6. Request the inspection report if you haven't received it—it will specify exactly which label or vehicle was cited.

Moderately serious, but far less severe than active hazmat loading/unloading violations. Our data shows that general hazmat loading violations (177.834A) carry a 99.2% OOS rate, while placard violations (177.817) reach 75.1%.

172.402(b)'s 0.0% OOS rate places it among the lowest-enforcement hazmat codes, comparable to placard maintenance issues (172.516 at 1.6% OOS). The violation is about proper labeling, not active unsafe transport—serious enough to fix, but not an immediate safety shutdown.

Our inspection database records show 172.402(b) citations have been distributed across six carriers, each with one citation. They include Southern California Edison Company (USDOT 59076), Old Dominion Freight Line (USDOT 90849), and Estes Express Lines (USDOT 121018).

Because only 6 citations exist all-time and none in the last 12 months, no carrier pattern emerges. This is a statistical rarity across the industry.

You can submit a DataQs (DataQuality System) challenge through the FMCSA portal. The strength of your contest depends on whether the violation is documentable (e.g., you can prove the label was present and compliant at the time of inspection) or equipment-based.

For 172.402(b), focus on: photographic evidence showing proper class number display, chain of custody records proving label compliance before inspection, or inspection error (e.g., citing the wrong vehicle). Gather supporting docs and submit within the regulatory timeframe.

Not urgent in terms of immediate safety risk, but fix it promptly to prevent repeat citations. Our data shows zero citations in the last 90 days and zero in the last 12 months, indicating very low enforcement frequency.

However, hazmat compliance is non-negotiable under DOT regulations. Verify all hazmat labels display class numbers clearly and legibly. A single citation is a warning; repeat findings could trigger carrier-level compliance reviews.

Both. Under FMCSA CSA rules, safety violations appear in both the driver profile and carrier profile, typically in the hazmat safety BASIC. A single 172.402(b) citation will not heavily impact either, given its 0.0% OOS rate and rarity.

However, if your carrier accumulates multiple hazmat violations across different codes, the carrier may face elevated scrutiny and increased roadside inspections. Ensure your fleet maintains systematic hazmat label audits to prevent pattern violations.