Hazardous Materials
Items that are considered a hazardous material or a dangerous good, in most cases, may not be mailable. Many common household items cannot be mailed through the US Postal Service™.
Examples of household products that may be mailable but have specific restrictions:
Aerosols
Cigarettes
Perfumes
Nail Polish
Batteries
Medicine or Drugs
Examples of non-mailable items:
Explosives
Ammunition
Alcoholic Beverages
Air bags
Gasoline
Poison
Most hazardous materials cannot be shipped through the US Postal Service.