Direct answers about 172.402B citations, out-of-service risk, and enforcement trends from 13 million real roadside inspections.
Ranks #2,664 of 3,146 FMCSR codes by citation frequency • OOS rate of 50.0% is above the FMCSR-wide average of 33.3%.
Display of class number on label
Direct answers grounded in TruckCodex inspection data
No. 172.402B is not an out-of-service violation. Across our inspection records, this code has never resulted in an out-of-service placement—the OOS rate is 0.0%. By contrast, the national average out-of-service rate across all FMCSR codes is 31.4%, making 172.402B exceptionally low-risk for roadside enforcement. You will receive a citation, but your truck will not be taken out of service.
No, 172.402B is among the least serious violations in the hazmat category. Our database shows peer violations like placarding and loading violations carry out-of-service rates between 18.5% and 99.2%. For example, general loading/unloading hazmat (177.834A-HMC) has a 99.2% OOS rate and 3,954 citations, while 172.402B has only 1 all-time citation and a 0.0% OOS rate. This code reflects a documentation or labeling issue, not a safety-critical defect.
Very rarely. Our inspection records show only 1 citation for 172.402B in all-time data, with 1 in the last 12 months and 0 in the last 90 days. This ranks 172.402B at #2796 out of 3,036 FMCSR codes by citation volume—among the lowest-enforced violations. The single citation on record occurred in Texas in December 2025, affecting a vehicle operated by Mono Mobile LLC.
Yes. All FMCSA violations can be contested through the DataQs (Data Quality Identification System) process. Since 172.402B involves label display—a documented, photographable finding—you should gather evidence showing the class number was correctly displayed. Submit a DataQs challenge within the timeframe specified in your citation notice, including photos, maintenance records, and any supporting documentation. Decisions are based on evidence review, not disputes about subjective judgment.
Texas is the only state with a recorded 172.402B citation in our 13 million inspection records, with 1 citation in the last 180 days and a 0.0% out-of-service rate. The sample size is extremely small—only one citation ever—so geographic patterns are not meaningful. Enforcement of this code is so rare that it does not cluster in any particular region.
Not urgent from an out-of-service standpoint, but urgent for compliance. While 172.402B has never triggered an out-of-service placement, the violation indicates hazmat labeling is not correct. Hazardous materials regulations require accurate class number display for safety and emergency response. Correct the labeling immediately to avoid a second citation and to ensure responders have accurate information in an emergency, even though the enforcement risk is low.
A 172.402B citation is recorded against the carrier (motor carrier) in the FMCSA system, not against you personally as a driver. However, hazmat violations do affect carrier safety ratings and CSA scores, which can impact the entire company. If you drive for a carrier with multiple hazmat violations, it increases scrutiny on all company vehicles. Ensure your carrier has a hazmat compliance program in place and that all drivers receive proper training on labeling requirements.
Where 172.402B is most commonly cited (last 180 days)
Other violations commonly found on the same inspection (last 90 days)
TruckCodex aggregates official public-sector datasets. See the Source registry for dataset-level coverage and the Freshness log for last-import timestamps.
Census, SAFER, SMS, Licensing & Insurance (L&I), roadside inspections, crashes, and authority history.
Vehicle recall campaigns, defect investigations, and consumer safety complaints (SCRS).
Cross-border carrier registry and Canadian recall campaigns where applicable.
TruckCodex is an independent aggregator; it is not affiliated with FMCSA, NHTSA, EIA, or Transport Canada. Always verify compliance-critical information directly with the originating agency.