In the early 1900s experts believed the best way to dispose of waste was to burn it for energy. Los Angeles County, California, encouraged its residents to install backyard trash burners. It was later determined that burning trash produces smog, damages the environment by producing carbon dioxide emissions, and is harmful to public health.

In 1970 the federal government passed a law, enforced by the EPA, to prevent ozone-damaging air pollution and protect public health.

A closed-loop waste system is one in which waste materials are returned to the product manufacturing system to be recycled instead of discarded in landfills or waterways.