What Is Used in Treated Wood Instead of CCA?

Chromated Copper Arsenate (CCA)

• CCA was once the most commonly used wood preservative used in construction. But arsenic leaches out of treated wood. Both low and high doses of arsenic from CCA-treated wood can lead to a number of health effects, from vomiting to nerve damage. No amount of arsenic is safe for children, who are most vulnerable to the arsenic in CCA, according the Healthy Building Network.

Borates

• Borate preservatives, such as disodium octoborate tetrahydrate, are derived from minerals that occur naturally in rocks, soil and water. Borates protect against fungi and termites, but not against water damage.

Alkaline Copper Quaternary (ACQ)

• ACQ is a mixture of copper oxide and a quaternary ammonium compound, and rotect against insect and fungal damage. Light tan to olive in color, ACQ can be used to treat wood that is above ground and immersed in fresh water.

Copper Azole

• Copper azole serves as an insecticide and fungicide, protecting such softwood species as red pine, Douglas fir and southern pine. There are two types of copper azole. Copper boron azole type A contains copper, boric acid and azole as tebuconazole. A newer form, copper azole type B, has a higher copper content and a small amount of azole as tebuconazole. Treating wood with either of these substances gives it a greenish-brown color.

Cyproconazole

• Cyproconazole protects wood from fungi when used in above-ground applications. However, it is not intended for use in projects in which the wood comes in contact with the ground. Cyproconazole contains the fungicides cyproconazole and didecyldimethylammonium chloride. The product is intended for industrial use only.

Propiconazole

• Propiconazole protects wood that is above ground only. It does not stave off insect damage. The preservative can be used in both commercial and industrial settings.