chromated copper arsenate

preservative

Also known as: CCA

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Last updated

July 20, 2026

Quick Summary

Chromated copper arsenate (CCA) is a chemical combination of chromium, copper, and arsenic used as a wood preservative. Developed in the 1930s, CCA was created by infusing wood with copper (to combat rot) and arsenic (as an insecticide). Chromium was added to stabilize these chemicals, creating a reaction that locked the pesticides into the wood. This process, often called pressure-treating, injects the chemicals under high pressure to protect wood from insects and decay. CCA is used on heavy structural elements like railroad ties, utility poles, and bridge timbers.12

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…solutions of compounds such as chromated copper arsenate (CCA), ammoniacal copper zinc arsenate (ACZA), and copper azole (CA-B). Creosote, PCP, and CCA are used on heavy structural members such as railroad ties, utility poles, marine pilings, and bridge timbers; ACZA and CA-B are used on common structural lumber.
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…solutions of compounds such as chromated copper arsenate (CCA), ammoniacal copper zinc arsenate (ACZA), and copper azole (CA-B). Creosote, PCP, and CCA are used on heavy structural members such as railroad ties, utility poles, marine pilings, and bridge timbers; ACZA and CA-B are used on common structural lumber.
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