Un-used photographic developer is a hazardous waste because it is considered a corrosive. Some cleaners for developer systems contain chromium and are also considered a hazardous waste. Although lead is restricted from household paints, it is still present in many industrial and artists' paints, and in ceramic glazes. Other heavy metals, such as cadmium, chromium, selenium, silver and mercury may also be present in these materials. Even if a metal ingredient such as cobalt, nickel or copper is not considered a hazardous waste, it is still restricted from sink disposal.
Wood finishing products also contain many hazardous components.
Compressed gas cylinders and spray cans can be considered a hazardous waste. Send unwanted compressed gas cylinders back to the supplier for disposal. Use entire contents of spray cans prior to disposal. If the spray can nozzle is defective, send it back to the manufacturer. If the content of a spray can or compressed gas cylinder is hazardous, then the non-empty container must be treated as a hazardous waste as well if you wish to dispose of it.