Inorganic substance that is stable in the environment, is liable to long-range transport, may bio-accumulate in human and animal tissue, and may have significant impacts on human health and the environment.

Note 1: Examples are arsenides, fluorides, cadmium salts and lead salts.

Note 2: Some inorganic chemicals, like crocidolite asbestos, are persistent in almost all circumstances, but others, like metal sulfides, are persistent only in unreactive environments; sulfides can generate hydrogen sulfide in a reducing environment or sulfates and sulfuric acid in oxidizing environments. As with organic substances, persistence is often a function of environmental properties.