Hazardous Materials
Q. What is a "Hazardous Material?"
A. A "Hazardous Material" is any material that, when it escapes its container, could cause harm to life or health, the environment, or property. Examples of hazardous materials include flammable and combustible materials, corrosives, explosives, oxidizers, poisons, materials that react violently with water, radioactive materials, biological materials, etc. Note: A "Hazardous Material" is not the same as a "Toxic Waste."
Q. What is a "Hazardous Waste?"
A. "Hazardous Waste" is simply a hazardous material you don't want anymore. If a hazardous material is disposed of, that makes it a hazardous waste. If a hazardous material is spilled, and cannot be effectively picked up and used as a product, it is considered to be a hazardous waste. If a hazardous material sits unused, and it is obvious there is no realistic intent to use the material, it is considered to be a hazardous waste. Hazardous wastes are only allowed to stay on your site for a ceartain amount of time (normally 90 days) before being disposed of through a registered hazardous waste contractor.
Links
Medical, Dental, and Veterinary Facilities, Hazardous Waste Generator Program 
Dental, Medical and Veterinary Offices - Managing your Hazardous Waste
Managing Universal Waste in California