EDTA

(ethylene-diamino-tetra-acetate)

A class of synthetic, phosphate-alternative compounds used to reduce calcium and magnesium hardness in water. EDTA is also used to prevent bleaching agents from becoming active before they're immersed in water and as a foaming stabilizer. EDTA does not readily biodegrade and once introduced into the general environment can re-dissolve toxic heavy metals trapped in underwater sediments, allowing them to re-enter and re-circulate in the food chain.

Found in: Conventional laundry detergents.