There are currently more than 50,000 different chemicals in common use in the United States. Roughly 1,000 others are added each year. Familiar hazardous materials include gasoline, household and industrial cleaners, disinfectants such as pool chlorine, and home and garden pesticides.
Hazardous wastes are unusable or unwanted hazardous materials.
Contaminated soil and other materials from cleanup of contaminated sites may also be considered hazardous waste. Human exposure to once-common hazardous materials such as lead in paint and asbestos in construction fireproofing is now known to be directly linked to poor health and early death. Hazardous material contamination of housing is a significant problem which affects children and other specific population groups. Many other common practices from the past and present continue to have both known and unknown effects on human health and the environment. In addition, San Francisco has numerous abandoned or underutilized properties in both industrial and residential areas, which have not been redeveloped due to concerns about the perceived cost of environmental clean-up.