Hazardous waste is waste that is dangerous or potentially harmful to our health or the environment. Hazardous wastes can be liquids, solids, gases or sludges. They can be discarded commercial products, like cleaning fluids or pesticides, or the byproducts of manufacturing processes. Hazardous waste must be disposed of properly at an approved facility. The EPA has created a set of criteria for determining and categorizing hazardous waste available on its website (http://www.epa.gov/osw/hazard/).