178.338-10A: MC338 Protection of fittings explained

Understand FMCSR 178.338-10A citations for MC338 fitting protection on hazmat vehicles. Learn what inspectors look for and how to stay compliant.

OOS Eligible
Severity Weight
8
OOS Eligible
Yes
BASIC Category
Hazardous Materials
Code System
FMCSR
Code:
178.338-10A
Code System:
FMCSR
BASIC Category:
Hazardous Materials
OOS Eligible:
Yes
Severity Weight:
8
Violation Group:
Package Integrity - HM

Ranks #2,813 of 3,146 FMCSR codes by citation frequency • OOS rate of 100.0% is above the FMCSR-wide average of 33.3%.

Violation Description

MC338 Protection of fittings

In-Depth Explainer

Grounded in TruckCodex roadside-inspection data

What 178.338-10A means in plain language

FMCSR 178.338-10A addresses the protection of fittings on MC338 cargo tanks used for hazardous materials transport. These fittings—connectors, valves, and other metal attachments on the tank exterior—must be properly shielded to prevent damage during loading, unloading, transport, and storage.

The regulation requires that fittings be installed, maintained, and protected in a way that keeps them functional and secure. Damage to fittings can compromise the tank's integrity, create leaks, or allow hazmat to escape. Inspectors check that protective covers, guards, or recessed mounting keep these components safe from impact.

What our enforcement data actually shows

Across our 13 million+ inspection records, 178.338-10A is rarely cited. We have recorded 1 all-time citation for this violation, with 0 citations in the last 12 months and 0 in the last 90 days. This code ranks #2796 of 3,036 FMCSR codes by citation volume, making it one of the least-cited hazmat regulations in the national database.

When this violation is cited, it carries serious weight: our data shows a 100.0% out-of-service rate—meaning every citation resulted in the vehicle being placed out of service. This is significantly higher than the all-FMCSR average OOS rate of 31.4%, underscoring that inspectors treat fitting protection breaches as critical safety issues that cannot be ignored.

Who gets cited most

Our inspection records show one carrier cited for this violation: Keith Morgan Trucking LLC (USDOT 291194) with 1 citation. The rarity of citations for this code means there is no meaningful geographic or fleet-based pattern to analyze. The limited enforcement volume reflects either strong industry compliance with fitting protection standards or limited inspector focus on this specific requirement during routine roadside inspections.

How severe is this compared to similar codes

Within the Hazardous Materials category, fitting protection sits at the extreme low end of enforcement frequency. By comparison:

  • 177.834A-HMC (General loading/unloading hazmat) has 3,954 all-time citations with a 99.2% OOS rate—vastly higher volume and similarly severe consequences.
  • 177.817(a) (Placarding violation) has 2,274 citations with a 75.1% OOS rate, reflecting more frequent inspector attention to visibility and labeling.
  • 172.602(c)(1) (Maintenance/accessibility of Emergency Response information) has 1,464 citations but a 0.0% OOS rate, indicating inspectors cite it but rarely remove vehicles from service.

The 100.0% OOS rate for 178.338-10A, though based on minimal citation volume, suggests that when inspectors do identify fitting protection problems, they view them as non-negotiable safety failures—on par with the most serious hazmat violations.

How to avoid it

Fitting protection is a straightforward pre-trip and maintenance issue:

  • Inspect all tank fittings during your pre-trip walk-around. Look for visible damage, loose covers, missing guards, or dents on valves, connectors, and discharge outlets. If anything is compromised, do not operate the vehicle—report it to your fleet maintenance immediately.
  • Verify protective covers and guards are in place and secure. Covers should be tight, not cracked or missing. Guards should be firmly mounted and not bent or separated from the tank.
  • Check that fittings are recessed or shielded appropriately. Modern MC338 tanks are designed with protected fittings to minimize impact exposure. Ensure nothing has been modified or removed that would expose connectors or valves to accidental strikes.
  • Report any collision or rough handling to dispatch and maintenance. Even minor impacts can damage fittings without visible tank damage. A fitting knocked loose or valve stem bent is a serious hazmat safety issue that must be addressed before the next load.
  • Keep cargo tank maintenance records current. Regular inspections by certified technicians ensure fittings remain protected and functional. Do not defer tank service or repairs related to fittings or protective hardware.

Because this violation carries a 100.0% out-of-service consequence and involves cargo tank integrity, prevention is far simpler and cheaper than getting cited and having your vehicle impounded at the roadside.

Last updated: 2026-04-20T17:59:55.567Z Based on TruckCodex inspection data See 178.338-10A Q&A → Fleet FAQ →

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