There is no such thing as a Class 3.1, or a Division 3.1 in the DOT scheme of classifying hazardous materials. The International Maritime Dangerous Goods Code used to use a Division 3.1 for the most flammable of flammable liquids, but that was removed from the code more than 10 years ago.
At present, hazardous materials may be described simply as "Class 3" if they meet the definition of flammable liquids.
DOT class 8 are corrosive.
DOT Hazard Class 3 is "Flammable Liquid".
Corrosive materials are in Hazard Class 8.
Explosive materials are in DOT hazard class 1.
Hazard class 4 is Flammable Solids.
Corrosive materials are in Class 8.DOT Hazard Class 8 for corrosives.
DOT Hazard Class 4 is for flammable solids such as magnesium metal.
It is DOT class 8.
DOT Class 1 is for explosives and is divided into six divisions.
Methanol is a flammable liquid and falls in hazard class 3.
Division 1.3 is predominately a fire hazard, with a minor blast hazard.
DOT hazard Class 8 contains corrosive materials such as acids and bases.