Hazard Classes

For purposes of transportation and shipping, each hazardous material is assigned to a hazard class. The list that follows provides examples of items that are subject to mailing restrictions or prohibitions.


Hazard Classes


Class 1:


Fireworks, ammunition, fuses, model rocket engines, automobile air bags

Class 2:


Aerosols, hairspray, scuba tanks, compressed gas containers, lighters, butane, propane

Class 3:

Flammable Liquids

Fuels (gasoline), items that contain or used to contain fuel (lighters, propane cylinders, used gasoline tanks), some paints and inks, furniture varnishes, perfumes

Class 4:

Flammable Solids

Matches, signal flares

Class 5:

Oxidizers and Organic


Oxidizing liquids, swimming pool chemicals, peroxides

Class 6:

Toxic Materials and Infectious Substances

Insecticides, pesticides, pepper spray, flea collars, infectious substances, sharps, patient specimens

Class 7:

Radioactive Materials

Scientific instruments, products requiring a radioactive warning label

Class 8:


Bleach, ammonia, batteries, drain cleaners, mercury, oven cleaners

Class 9:

Miscellaneous Hazardous


Magnets, dry ice, self-inflating lifesaving devices, lithium and lithium-ion batteries

Just because an item is NOT on this list does not mean that the item is mailable — be sure to ask before mailing any items that could be considered hazardous.