Plastic is everywhere—it's used in consumer products and packaging of all kinds. And while it solves a lot of problems for manufacturers and can seem convenient to consumers, there are also serious risks to human health and the environment from its widespread use. Three plastics have been shown to leach toxic chemicals when heated, worn or put under pressure: polycarbonate, which leaches bisphenol A; polystyrene, which leaches styrene; and PVC, or polyvinyl chloride, which break down into vinyl chloride and sometimes contains phthalates that can leach. And for more specific information about these and other chemicals found in plastics, including what they do and why they're bad for you, look below.

Bisphenol A (BPA)

One of the most pervasive chemicals in modern life. It's a building block of polycarbonate (#7 is often polycarbonate) plastic and is used in thousands of consumer products, including food packaging, baby goods! BPA exposure may disrupt normal breast development in ways that predispose women for later life breast cancer.

Phthalates

Phthalates are a group of endocrine-disrupting chemicals found in PVC or #3 plastic. Phthalate exposure has been linked to early puberty in girls, a risk factor for later-life breast cancer. Some phthalates also act as weak estrogens in cell culture systems.

Vinyl Chloride

Vinyl chloride is formed in the manufacture of polyvinyl chloride (PVC) or #3 plastic. It was one of the first chemicals designated as a known human carcinogen by the National Toxicology Program (NTP) and the International Agency for Research on Cancer (IARC). It has also been linked to increased mortality from breast cancer among workers involved in its manufacture.

Dioxin

Dioxin is formed in the manufacture of polyvinyl chloride (PVC) or #3 plastic. Dioxin has been classified by the International Agency for Research on Cancer (IARC) and the Environmental Protection Agency (EPA) as a known human carcinogen, and is also an endocrine disruptor.

Styrene

Styrene can leach from polystyrene or #6 plastic and is found in Styrofoam food trays, egg cartons, disposable cups and bowls, carryout containers and opaque plastic cutlery. It has been classified by the International Agency for Research on Cancer (IARC) as a possible human carcinogen.