Imminent hazard means the existence of a condition relating to hazardous material that presents a substantial likelihood that death, serious illness, severe personal injury, or a substantial endangerment to health, property, or the environment may occur before the reasonably foreseeable completion date of a formal proceeding begun to lessen the risk of that death, illness, injury, or endangerment.
49 CFR § 109.1
For purposes of this part, all terms defined in 49 U.S.C. 5102 are used in their statutory meaning. Other terms used in this part are defined as follows: