chromated copper arsenate

noun

chro·​mat·​ed copper arsenate ˈkrō-ˌmā-təd- 

: a chemical combination of chromium, copper, and arsenic used to protect wood against insects and decay

Then, in the 1930s, scientists found a way to infuse wood with a solution that included copper (toxic to the fungi that cause rot) and arsenic (then the most common insecticide). To ensure the protection would last and builders and the environment wouldn't be hurt, they also added chromium. It triggered a chemical reaction that locked the pesticides into the wood. The formula became known as chromated copper arsenate, or just CCA. But the industry called it pressure-treated because the chemicals were injected under great pressure.

—Curtis Rist

—abbreviation CCA

Examples of chromated copper arsenate in a Sentence

Recent Examples on the Web

For projects around homes, the main replacement was lumber treated with chromated copper arsenate, or CCA, which was introduced in the 1940s. —Jeanne Huber, Washington Post, 17 Aug. 2020

Word History

First Known Use

1962, in the meaning defined above