All hazardous materials subject to the regulations of the Pipeline and Hazardous Materials Safety Administration (PHMSA) within the USDOT must be classified as one or more of the nine hazard classes – or a division of a hazard class – identified at 49 CFR 173 subpart C (for Class 1 Explosives), subpart D (for hazardous materials other than Class 1 Explosive and Class 7 Radioactive), and subpart I (for Class 7 Radioactive).  while most hazard classes/divisions have very specific definitions based on their potential hazards, i.e. flash point, rate of corrosion, lethal dosage, &etc, one hazard class is deliberately vague in its definition.  Its vague definition results in the hazard class being applicable to many materials that might not normally be subject to the Hazardous Material Regulations.  It is hazard class 9 Miscellaneous, and the subject of this article. (more…)