The Occupational Safety and Health Administration (OSHA) define a hazardous material as any substance or chemical which has been determined to be either a health hazard or a physical hazard.

Hazardous materials include but are not limited to substances which are:
• Carcinogens 
• Irritants
• Corrosives (to human tissue or metal)
• Combustible
• Flammable
• Oxidizers (accelerate fire)