What 178.338-11(b) means in plain language
FMCSR 178.338-11(b) requires that MC338 cargo tanks—the specialized containers used to transport certain hazardous liquids and gases—have a properly functioning manual shutoff valve. This valve is a critical safety device that allows a driver or emergency responder to immediately stop the flow of cargo in case of an accident, leak, or other emergency.
The regulation focuses on the mechanical integrity and operational readiness of this valve. If an inspector finds that your MC338 tank's manual shutoff valve is missing, damaged, corroded, or not functioning as designed, you can be cited. The valve must be accessible, properly installed, and capable of reliably closing to contain hazardous material if needed.
What our enforcement data actually shows
Across our database of 13 million+ roadside inspections, this specific violation is relatively uncommon. Our records show 4 all-time citations for 178.338-11(b), with 0 citations in the last 12 months and 0 in the last 90 days. This code ranks #2480 out of 3,036 FMCSR codes by citation volume, placing it in the lower-frequency enforcement tier.
Of the 4 citations ever recorded, 1 resulted in an out-of-service order—a 25.0% OOS rate. This is notably lower than the all-FMCSR average OOS rate of 31.4%, suggesting that inspectors have found most violations of this code to be correctable defects rather than immediate safety threats requiring vehicle removal from service.
The absence of citations in the past 90 days indicates either that this violation is becoming rarer or that fewer MC338 tanks with this specific defect are being encountered at weigh stations and inspection sites. For drivers currently cited, the statistical likelihood of an out-of-service placement remains relatively modest compared to other hazmat-related codes.
Who gets cited most
Our inspection records show that citations for 178.338-11(b) are distributed across small carrier and owner-operator entities. The top carriers cited include Coastal Transport Co Inc (USDOT 36647), Julio Rodolfo Gonzalez Olveda (USDOT 2927508), Alberto Vazquez Perez (USDOT 3260169), and Jorge Prisciliano Renteria Campos (USDOT 3551569)—each with 1 citation in our all-time database. The extremely small citation volume means no clear geographic or carrier pattern emerges; enforcement appears sporadic and scattered rather than concentrated.
Vehicle makes cited include KW and POLA, each appearing once in our records. The low volume of citations means individual vehicle models or carrier fleets should not be considered high-risk; this is simply too rare an occurrence to establish meaningful trends.
How severe is this compared to similar codes
Within the hazardous materials inspection category, 178.338-11(b) sits at the lower end of enforcement frequency. For comparison, our data shows that 177.834A-HMC (general loading/unloading of hazmat) has been cited 3,954 times with a 99.2% OOS rate—meaning almost every violation results in immediate removal from service. Similarly, 177.834(a) has 3,839 citations with a 97.9% OOS rate.
Even among less-severe hazmat codes, 178.338-11(b) differs markedly. The code 172.516(c)(6), which addresses deteriorated or obscured placarding, has 1,796 citations but only a 1.6% OOS rate. And 172.602(c)(1), addressing maintenance of emergency response information, shows 1,464 citations with a 0.0% OOS rate. These comparisons show that shutoff valve defects are treated less harshly than loading/unloading violations but similarly to other equipment-condition hazmat codes.
How to avoid it
To prevent a 178.338-11(b) citation, incorporate manual shutoff valve inspection into your pre-trip routine if you operate an MC338 tank:
- Visually inspect the valve location before each trip. Know where your shutoff valve is mounted and verify it is not cracked, heavily corroded, or obviously broken.
- Test the valve manually (when safe and appropriate) to confirm it moves freely and is not frozen or stuck due to corrosion or debris.
- Check for leaks or weeping around the valve that might indicate internal failure or improper seating; report any to your carrier's maintenance team immediately.
- Document the condition in your vehicle condition report (DVIR). If you notice any defect, do not accept the vehicle for a hazmat load until repairs are complete.
- Coordinate with your carrier's maintenance schedule. Ensure that MC338 tanks in your fleet receive regular inspections and that any corroded or damaged shutoff valves are replaced before they cause a violation.
- Understand your tank's design. Familiarize yourself with the specific shutoff mechanism on your assigned MC338 tank—not all valve designs operate identically, and knowing yours helps you spot irregularities.
Because citations for this code are infrequent, most drivers will never encounter this violation. However, if your operation involves hazmat transport via MC338 tank, basic pre-trip awareness of this critical safety device will keep you compliant and protect public safety.