What 178.345-5D means in plain language
When you're hauling hazardous materials in a DOT406, DOT407, or DOT412 tank vehicle, every opening on that tank—including the manhole—must be properly secured. This isn't about a loose bolt or minor wear. The regulation requires that the manhole closure hardware stays intact, sealed, and unable to open during transport.
If an inspector finds that your manhole isn't securely fastened, isn't properly sealed, or shows signs of compromised integrity, you'll be cited under 178.345-5D. The hazmat you're carrying depends on that seal. If it fails, you're risking a spill that endangers the road, other drivers, emergency responders, and the environment. That's why enforcement is strict when it happens.
What our enforcement data actually shows
Across our 13 million+ roadside inspection records, we've documented 23 all-time citations for 178.345-5D. In the last 12 months, inspectors issued 13 citations, and in the last 90 days, 4 citations appeared in our database. This code ranks #1881 of 3,036 FMCSR codes by citation volume—so it's relatively uncommon, but when it does appear, it's taken seriously.
The enforcement picture is striking: 19 of those 23 citations (82.6% out-of-service rate) resulted in the vehicle being pulled from service immediately. By contrast, across all FMCSR codes, the average out-of-service rate is 31.4%. That means when an inspector cites 178.345-5D, the truck is nearly 2.6 times more likely to be sidelined compared to the FMCSR average. If you're cited for this violation, assume your vehicle will be taken out of service until the defect is corrected and re-inspected.
Who gets cited most
Our inspection records show Texas accounts for 6 citations in the last 180 days, and all 6 of those (100.0% rate) resulted in out-of-service placements. The data in our database indicates that this violation doesn't concentrate heavily in any one state—Texas leads, but the citation count remains low nationwide, reflecting how uncommon but serious this defect is when found.
Regarding specific fleets, our data shows carriers such as TRANSPORTES Y MAQUINARIA MORO SA DE CV and BLANCA ESTHER ALEJANDRO MARTINEZ each accumulated 2 citations in our all-time records. These numbers reflect the fact that manhole securement issues can recur if maintenance protocols aren't consistently applied across a fleet's tank equipment.
How severe is this compared to similar codes
Hazmat violations in general carry high enforcement weight. Our inspection records show general loading/unloading hazmat violations (code 177.834A-HMC) generated 3,954 citations with a 99.2% out-of-service rate—higher than 178.345-5D's 82.6% rate but in the same ballpark. Placarding violations (177.817(a)) logged 2,274 citations at 97.9% out-of-service, also substantially higher citation volume. By contrast, placard deterioration (177.817(e)) saw 2,038 citations but only a 5.2% out-of-service rate, showing that enforcement severity varies sharply depending on the specific hazmat defect.
What distinguishes 178.345-5D is its rarity combined with its teeth: when it appears, enforcement is swift and unforgiving. The 82.6% out-of-service rate reflects the regulatory reality that tank integrity is non-negotiable in hazmat transport.
How to avoid it
Manhole securement begins with pre-trip inspection discipline. Across our last 90 days of co-occurring violations, we see patterns that point to broader maintenance gaps:
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Inspect your tank closure hardware before every dispatch. Check that the manhole cover or bolted closure sits flush against the gasket, that no cracks or corrosion are visible in the closure ring, and that bolts are hand-tight (not over-tightened, which can crack the seal). If you see rust, corrosion, or a cover that doesn't sit evenly, do not move the vehicle—report it to maintenance.
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Don't confuse "sealed" with "stuck". The closure should require deliberate effort to open but should not be rusted shut or frozen. If you find yourself forcing a manhole cover or straining bolts during your pre-trip, the gasket or closure ring may already be failing. Document it and get it serviced.
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Know your vehicle type. Across our all-time citations, FRHT (Freightliner) vehicles account for 7 citations, followed by POLA (Polar), VOLV (Volvo), and others. If you operate one of these common tanker platforms, pay extra attention to the specific manhole design on your unit and confirm with your maintenance team how the OEM expects the closure to feel when properly secured.
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Watch for secondary brake and steering issues. Our data shows that in the last 90 days, inspections citing 178.345-5D also frequently cited slack adjusters (393.47E), steering wear (393.53B), and brake defects (393.47C, 393.48A). This pattern suggests that vehicles with manhole issues may also be under-maintained in other mechanical areas. If you know your tank closure needs work, schedule a full mechanical inspection—don't assume only the manhole is the problem.
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Never overtighten or use makeshift hardware. Replacement bolts or washers that don't match OEM spec can compromise the seal and invite an inspector citation. Use only approved replacement hardware and torque to manufacturer specifications.
Manhole securement is non-negotiable in hazmat service. The 82.6% out-of-service rate tells you exactly how seriously FMCSA takes this violation. Catch it in your own pre-trip, and you'll never have to face that roadside stop.