Direct answers about 172.328C citations: OOS rates, what happens next, and how serious this violation really is based on 13M+ inspection records.
Ranks #2,215 of 3,146 FMCSR codes by citation frequency • OOS rate of 0.0% is below the FMCSR-wide average of 33.3%.
Not marked with "QT" or "NQT" on MC330 or MC331 cargo tank
Direct answers grounded in TruckCodex inspection data
No. Across our 13 million inspection records, no trucks cited for 172.328C have been placed out of service. The OOS rate for this code is 0.0%, compared to the FMCSA average of 31.4% across all FMCSR codes. This is a documentation and marking violation, not an immediate safety emergency that triggers roadside removal. However, you'll still need to correct the marking before the next inspection.
Compared to peer hazmat placarding violations, 172.328C is relatively minor. Our data shows that similar placard and marking codes in the hazmat category have dramatically higher OOS rates: general loading violations (177.834A-HMC) hit 99.2% OOS rate, and general placarding violations (177.817(a)) reach 75.1%. By contrast, 172.328C has never resulted in an out-of-service order. It's a compliance marking issue, not an equipment or operation failure.
First: inspect your MC330 or MC331 cargo tank for proper QT (qualified tank) or NQT (non-qualified tank) marking. Second: document the current state with photos. Third: if the marking is missing or illegible, correct it immediately—our data shows 1 citation in the last 90 days and a rising trend through 2025–2026, meaning inspectors are actively watching. Fourth: if you share the tank with other carriers or contractors, verify who maintains marking compliance. Check for any related placard issues (172.519 appears in co-occurring violations).
Citation volume is very low. Our inspection records show 10 all-time citations total, with 7 in the last 12 months and 1 in the last 90 days. Monthly distribution is sparse: 1 citation in July 2025, 3 in August 2025, then 1 each in November 2025, December 2025, and February 2026. This is the #2191 ranked code out of 3,036 FMCSR codes by citation volume, making it a rare citation overall.
Texas leads by far in recent months. Our last 180 days of data show Texas with 3 citations and a 0.0% OOS rate. Beyond Texas, citation frequency drops sharply—this violation is geographically sparse overall. If you operate primarily in Texas and haul hazmat in MC330/MC331 tanks, pay closer attention to tank marking compliance than operators in other regions.
Yes, you can challenge it through FMCSA's DataQs (Data Quality System) portal if you believe the citation is factually incorrect—for example, if your tank does bear the required QT or NQT marking and the inspector missed it, or if your tank type doesn't actually require the marking under the regulations you operate under. DataQs challenges focus on factual accuracy of the inspection record, not on whether the regulation itself is fair. Document your tank's current marking status with photos and the date before filing.
MIDSTREAM TRANSPORTATION COMPANY (USDOT 2497677) has the highest count with 2 citations. The remaining citations are spread across eight other carriers, each with 1 citation: WATER TECH TRANSPORTATION LLC, WHEAT ENERGY SERVICES INC, SUREGROW AGRICULTURAL TRANSPORTATION INC, AHRENS BROTHERS TRANSPORT INC, L E B ENTERPRISES INC, INTER PETROLEUM LLC, RED RIVER TRANSPORT INC, and SPECIALIZED INTERNATIONAL TRANSPORT LLC. This suggests the violation is isolated and not systemic to any single carrier's compliance program.
Moderately urgent. While no trucks have been taken out of service for this code, the upward trend in 2025 (3 citations in August alone) suggests inspectors are prioritizing tank marking checks. Fix the QT/NQT marking on your MC330 or MC331 tank before your next roadside inspection—don't wait. The violation is straightforward to remedy (paint, label, or re-stencil the tank), and correction documentation can be valuable if you face follow-up inspections in high-citation states like Texas.
Where 172.328C is most commonly cited (last 180 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.