For a long time, CCA (Chromated Copper Arsenate) was the primary wood preservative. CCA-treated wood protects against all major forms of destructive attack and is effective for many years. More recently, preservative manufacturers switched to ACQ (Alkaline Copper Quaternary). ACQ is also effective for decades, reducing demands on forest resources. Another common preservative is a solution containing natural, environmentally safe mineral salts called borates. Borate lumber has a powerful barrier against termites — even the extremely destructive Formosan termite. The new generation of pressure-treated wood uses micronized copper as a preservative. This method enables ProWood to stand up against termite damage and fungal decay.