What 172.301(b) means in plain language
FMCSR 172.301(b) requires that packages, freight containers, or transport vehicles carrying hazardous materials display the proper markings. When an inspector cites you for this code, it means they found that your shipment or vehicle lacked the required hazmat markings, or the markings that were present were defective—meaning they were incomplete, obscured, faded, damaged, or otherwise not clearly visible and legible.
These markings are critical safety tools. They alert anyone handling, transporting, or responding to an emergency with your cargo that hazardous materials are present. A defective or missing marking defeats that purpose and puts handlers, emergency responders, and the public at risk. The regulation doesn't allow exceptions; if you're carrying hazmat, the marking must be there and in good condition.
What our enforcement data actually shows
Across our 13 million+ inspection records, 172.301(b) has been cited 46 times all-time. In the last 12 months, we've recorded zero citations for this code, and zero in the last 90 days. Of the 46 all-time citations, none resulted in an out-of-service order—giving this code a 0.0% OOS rate. This is significantly lower than the all-FMCSR average OOS rate of 31.4%, which means inspectors are treating this violation as a correctable defect rather than an immediate safety showstopper.
However, the rarity of citations doesn't mean the violation is unimportant. It suggests that most carriers and drivers catch marking defects during pre-trip inspections or that violations are rare in the population. Nationally, 172.301(b) ranks #1663 out of 3,036 FMCSR codes by citation volume, placing it in the lower-frequency bracket.
Who gets cited most
Our inspection records show that hazmat marking violations are distributed across multiple carriers and vehicle types. Among all-time citations, carriers such as Alvin S Ruiz (USDOT 2623711) and Lawrence Tractor Co Inc (USDOT 2607253) appear with 2 citations each; Rancho Tree Service (USDOT 3196349) and Bei Construction Inc (USDOT 2764381) also have 2 citations each. The remaining citations are spread among carriers with 1 citation on record.
Vehicle make data from our database shows Ford leading with 5 citations, followed by Intl and Freightlin with 2 each. This spread across makes and carriers indicates the violation is not concentrated in any single fleet or vehicle type, suggesting it's a compliance issue that can affect any hazmat shipper or carrier.
How severe is this compared to similar codes
Within the Hazardous Materials category, marking and placarding violations vary widely in enforcement severity. For perspective:
- 177.834A-HMC (General loading/unloading hazmat) has 3,954 citations with a 99.2% OOS rate—vastly more serious.
- 177.817(a) (Placarding violation) has 2,274 citations with a 75.1% OOS rate—also much stricter enforcement.
- 172.516(c)(6) (Placard damaged, deteriorated, or obscured) has 1,796 citations but only a 1.6% OOS rate—very similar in enforcement leniency to 172.301(b).
- 172.602(c)(1) (Maintenance/accessibility of Emergency Response information) has 1,464 citations with a 0.0% OOS rate—identical to 172.301(b).
The data shows that marking and placard defects, when they involve damage or deterioration, are often treated as correctable violations rather than grounds for immediate removal from service. In contrast, placarding violations and unsafe loading/unloading practices draw much stricter enforcement.
How to avoid it
Preventing a 172.301(b) citation requires diligence at the pre-trip stage and careful handling throughout transport:
-
Inspect all hazmat markings before leaving the shipper. Before accepting a hazmat load, verify that every package, container, and the transport vehicle itself displays the correct, legible hazmat markings. Check that labels are not peeling, faded, or obscured by dirt, grease, or wear.
-
Protect markings from weather and handling damage during transport. Tarps, cargo covers, and secure tie-downs help prevent markings from being torn, rubbed off, or obscured. Pay particular attention to markings on the sides and rear of your vehicle where road debris and weather exposure are highest.
-
Clean and restore markings at regular intervals on long hauls. If you're on the road for several days or weeks, take time to inspect and clean markings so they remain visible. A marking compromised by road grime is as problematic as a faded one.
-
Know what markings are required for your specific cargo. Different hazmat classes require different markings. Familiarize yourself with the hazmat shipping papers and the placard requirements so you can spot omissions or errors before an inspector does.
-
Report defective markings immediately to your dispatcher or the shipper. If you discover that a package or vehicle marking is defective after loading, notify your company at once. Do not proceed with transport until the marking is corrected.
-
Use quality labeling materials and application methods. If your fleet applies markings in-house, ensure labels are applied to clean, dry surfaces and are rated for the environmental conditions they'll face (moisture, UV, temperature extremes, abrasion).