Dislodgeable arsenic Hexavalent chromium Chromated
Chromated copper arsenate (CCA) is a pesticide that extends the service life of wood products by 20–40 years. CCA-C is the most common formulation for residential use and is comprised of 48% CrO3, 34% As2O5 and 19% CuO by weight, with final As concentrations being 2000–5000 mg/kg (AWPA, 1998). During treatment, CCA binds to wood fiber, leading to AMD 3465 of carcinogenic hexavalent chromium (CrVI) to the non-carcinogenic trivalent form (CrIII) (Radivojevic and Cooper, 2008). CCA-wood structures around homes include fences, decks, and staircases. Between 1995 and 2003, 11 million new single-family homes were built in the US, with 3.4 million having decks constructed from CCA-wood. It is estimated that more than 21 million homes in the US had decks made from CCA-wood in 2007. Use in new residential construction ended in 2004, but ~ 150 million pounds of CCA were used by the wood treatment industry in 2010, primarily for use on farms, commercial properties and for export (Shupe, 2012).