For the last 70 years, people have been using pressure-treated (PT) wood for projects where resistance to moisture, rot, and insect damage is important: porches, decks, play sets, fences, and other outside structures. Most professionals recommend using PT wood for all outdoor projects. However, many people have questions about the safety of this material and the chemicals used to preserve the wood.
Until 2003, the most common preservative used was chromated copper arsenate (CCA). Health concerns led to replacement of CCA by a range of other chemicals. Most contain high levels of copper, which is less toxic than CCA because it is not absorbed by the body. (Read more….)