When chromated copper arsenate (CCA) was withdrawn from the residential market in 2003, the chemical industry responded by introducing wood-treating formulas that still contained copper, but that replaced the arsenic and chromium with other, less-harmful active ingredients. These formulas have now had more than 10 years to prove themselves in the U.S. market-time enough for suppliers and builders to assess the performance of lumber treated with them. The good news? It performs pretty well, both in long-term scientific tests and on decks in the field. The bad news? Some users have reported premature decay, particularly in severe exposures or in ground-contact situations.    Read more