While most of these products are necessary for proper operation and maintenance, they are all toxic. Used oil is a hazardous waste. The hazards associated with used oil result from the various additives used in its manufacture and from the heavy metal contaminants picked up from use in the internal combustion engine. Oil poured down household drains or directly onto the ground can reach the lakes, rivers and ground water. One quart of oil can pollute 250,000 gallons of drinking water.
Used oil is recyclable.
Two and one half quarts of lubricating oil is gained by re-refining one gallon of used oil. You can participate in oil recycling by draining the used oil into a clean container with a tight fitting cap. Do not mix the recovered oil with any other liquid and make sure the oil is free from dirt, leaves and other debris. Many auto parts stores will accept your oil for recycling. Automobiles use lead-acid batteries.