3
Explosives that have no explosive hazard are not explosives. Materials that have a fire hazard but no explosive hazard are Class 2 if they are gasses, class 3 if they are liquids, and class 4 if they are solids.
The DOT classification for Spontaneously Combustible material is Division 4.2
Class 4 division 3 (more properly called Division 4.3) is a Dangerous When Wet Material.
DOT Hazard Class 3 is "Flammable Liquid".
Class 4 division 1 (more properly called Division 4.1) is for flammable solids.
DOT Class 3 is for flammable liquids, but there is no subdivision of the class so there is no division 3 for this class.
Division 2.3 is for poisonous gasses.
Methanol is a flammable liquid and falls in hazard class 3.
Class 4 division 3 (more properly called Division 4.3) is a Dangerous When Wet Material.
Division 2.3 is for poisonous gases.
There is no Class 3 Division 2; Class three has no subdivisions.