Leaks and shell damage are the first things to look for on a tank vehicle. On a DOT specification cargo tank in hazardous materials service, what does federal regulation require once such a condition is found?

Explanation

Evidence of dents, cuts, gouges, corroded or abraded areas, leakage, or any other condition that might render the tank unsafe for hazardous materials service requires a test and inspection before further use, and the regulation applies that duty without regard to any other test or inspection requirement. A clean periodic record therefore buys nothing: a condition found this morning overrides a due date months out. The same paragraph goes further on two of those findings, calling for thickness testing of any dented, cut, dug, gouged, corroded or abraded area and repair of any sign of leakage. The three wrong options all let the vehicle keep running, either on the strength of its schedule or on a distinction the regulation does not draw between damage that has leaked and damage that has not, when the rule is written around any condition that might make the tank unsafe.

Source: 49 CFR 180.407(b)(1)