are considered hazardous?
A waste can be EXPLOSIVE or highly flammable, or react violently with other substances. Garbage trucks have burned and sewers exploded because people put flammable wastes in them.
A waste can be CORROSIVE. Discarded auto batteries contain acid that can eat away many substances.
Some wastes are poisonous, or can cause cancer, birth defects, or other health problems. These wastes are TOXIC.
Some wastes are INFECTIOUS, like sewage. Hospitals produce infectious wastes and, very rarely, a household may. (In such cases the doctor or local public health department tells the family how to deal with the wastes.)
RADIOACTIVE wastes can cause illness. It's unlikely a home would ever have highly radioactive waste to dispose of, but wastes that are only mildly radioactive, or very dilute, can also increase a person's chances of developing cancer if they are eaten or inhaled. For example, some camping lantern mantles contain thorium, a radioactive element. When the mantle is replaced, care should be taken not to inhale the ashes of the old mantle.