There is a great deal of confusion about the toxicity of pressure treated wood. Previously, wood was treated with chromate copper arsenate (CCA) which is highly toxic chemical pesticide. Recently, however, the industry has moved away from CCA use in residential applications and the majority of available treated wood is treated with either alkaline copper quat (ACQ) or copper azole (CBA-A or CA-B). These treatments are far less toxic and are considered to be a much safer material. It should be noted that keepers have kept chameleons in CCA wood enclosures for years without ill effects and the same is true of ACQ and CA-B wood enclosures. At the same time, when using such wood for your enclosures, you should be sure to allow the wood ample time to dry out after you buy it and you might consider sealing the wood as an added precaution.