The chemical mixtures in fireworks are extremely volatile, and it is very dangerous to handle them unless professionally trained. According to the ATF, it is illegal to make your own fireworks in every state. It is also illegal to possess any homemade firework that has not been government approved as a “consumer” firework. Never attempt to make your own fireworks or in any way tamper with or alter professionally made fireworks. Attempting to make homemade fireworks can result in property damage, serious injury, or a fatal accident.