What 173.315(a) means in plain language
FMCSR 173.315(a) requires compliance with general requirements for cargo tanks and portable tanks that transport Class 2 hazardous materials—primarily compressed gases, liquefied gases, and refrigerated liquids. This regulation sets the baseline safety standards for how these tanks must be constructed, maintained, and operated during transport.
Class 2 materials are inherently hazardous because they're stored under pressure or at extreme temperatures. The regulation ensures that the tank itself—its design, welds, fittings, relief devices, and overall structural integrity—meets federal specifications before and during every shipment. A citation under 173.315(a) means an inspector found that your cargo tank or portable tank did not meet one or more of those general requirements.
What our enforcement data actually shows
Across our 13 million real roadside inspection records, 173.315(a) has been cited only 1 time in all-time data. In the last 12 months, there have been 0 citations, and in the last 90 days, 0 citations. This code ranks #2796 out of 3,036 FMCSR codes by enforcement volume.
The out-of-service rate for this citation stands at 0.0%—the single historical citation did not result in an out-of-service order. For context, the all-FMCSR average out-of-service rate is 31.4%, which means 173.315(a) is far less likely to trigger an immediate roadside shutdown compared to most other violations in the hazardous materials space.
Who gets cited most
Our inspection database shows that NATTCO INC (USDOT 2517798) received the single documented citation for this code. The vehicle cited was a Ford. Because this violation is extremely rare in our enforcement data, geographic and carrier trends are not meaningful to report.
How severe is this compared to similar codes
Hazardous materials violations in the same regulatory category show dramatically different enforcement patterns. Loading and unloading violations under codes 177.834A-HMC and 177.834(a) account for 3,954 and 3,839 citations respectively, with out-of-service rates of 99.2% and 97.9%—meaning those violations almost always result in immediate vehicle removal from service.
By contrast, placarding violations like 172.516(c)(6) for damaged or obscured placards have logged 1,796 citations with only a 1.6% out-of-service rate. The data shows that while cargo tank design and construction defects are taken seriously in the hazmat enforcement framework, they are cited far less frequently than loading, unloading, and placarding errors.
How to avoid it
- Conduct a pre-trip cargo tank inspection before every Class 2 hazmat shipment. Check for visible cracks, corrosion, leaks, loose fittings, and damaged relief valves. Do not depart with defects.
- Verify tank certification and documentation. Ensure your cargo tank has current DOT specifications, hydrostatic test certificates, and proof of compliance with the design standards for the specific gas or liquid being transported.
- Know your tank's rated capacity and pressure limits. Overloading or delivering incompatible cargo to a tank designed for different Class 2 materials is a direct violation.
- Report tank damage immediately. If you discover cracks, leaks, or structural issues at a shipper or receiver facility, do not accept the load. Report it to your carrier's safety team and the facility operator.
- Keep records of tank maintenance and repairs. Auditors and roadside inspectors will ask for proof that your tank is being maintained according to federal standards.