FMCSR 172.328E: Non-Odorized LPG Marking Citation FAQ

No. This citation does not result in an out-of-service order. Across our inspection database, the 0.0% out-of-service rate for 172.328E shows that FMCSA does not remove vehicles from service for this violation. This is significantly lower than the 31.4% average out-of-service rate across all FMCSR codes, meaning this is treated as a less severe finding than most hazmat-related violations.

This is a relatively low-enforcement violation. Our records show only 4 all-time citations for 172.328E out of 3,036 total FMCSR codes, ranking it #2480 by citation volume. For comparison, similar hazmat marking violations like 177.817(a) (placarding violations) have been cited 2,274 times with a 75.1% out-of-service rate. The rarity and zero out-of-service rate indicate this is treated as a documentation or marking issue rather than an immediate safety threat.

Immediate steps:

1. Document the issue — photograph the cargo tank and note the specific marking or label that was missing or incorrect.
2. Verify your cargo — confirm the LPG product is indeed non-odorized and review your bill of lading.
3. Request the inspection report — obtain the full roadside inspection report from the officer.
4. Contact your carrier's safety manager — if you're a company driver, report the citation immediately.
5. Review 49 CFR 172.328(e) — understand the specific marking requirement for non-odorized LPG containers.
6. Correct and document — ensure the tank is properly marked going forward and keep records of the correction.

Texas is the only state in our 180-day enforcement snapshot with recorded 172.328E citations, accounting for 2 citations with a 0.0% out-of-service rate. The extremely low overall citation volume (3 in the last 12 months, 0 in the last 90 days) means this violation is rarely enforced nationwide. The concentration in Texas reflects the state's significant LPG transport industry, but even there the citation count remains minimal.

Yes, you can contest this citation through the DataQs (Data Quality) system. The DataQs process allows drivers and carriers to challenge roadside inspection records and request corrections. Since 172.328E is a marking or documentation-based violation (not a safety equipment failure), you have grounds to contest if: the marking was actually present and the inspector missed it, the product classification was incorrect, or the citation was recorded in error. Submit your challenge within 90 days through the CSA website with photographic or shipping documentation evidence.

Extremely rare. Our database shows only 4 all-time citations for this code. California Gas Transport Inc (USDOT 589266) accounts for 2 of those citations, while Ahrens Brothers Transport Inc and Midstream Transportation Company each have 1. The fact that this violation appears in only a handful of carriers across 13 million inspections suggests it is either very specific to certain operations, caught infrequently during inspections, or actively complied with by most LPG transporters.

This citation means an inspector found that a cargo tank carrying non-odorized liquefied petroleum gas (LPG) did not have the required marking or label identifying it as such. Non-odorized LPG must be clearly marked to alert emergency responders and handlers to its nature, as it lacks the distinctive smell of standard LPG. The violation addresses the labeling requirement, not the safety of the product itself, which is why it carries a 0.0% out-of-service rate.

December and July are the only months in the past 12 months with recorded 172.328E citations—2 in December 2025 and 1 in July 2025. The extremely low and sporadic citation pattern (0 citations in the last 90 days) means there is no consistent seasonal enforcement trend. This violation is too infrequent to predict enforcement timing based on historical patterns.