・ Explosives
・ Flammable liquid
・ High pressure gas
・ Combustible substances
・ Oxidizing substances
・ Poisons
・ Corrosive substances
・ Radioactive material
・ Others
You cannot send aviation dangerous goods by international mail.
https://www.post.japanpost.jp/int/use/restriction/airmail/index.html
Country / Region Information (International Postal Conditions)
https://www.post.japanpost.jp/cgi-kokusai/
