Copper Naphthenate vs Chromated Copper Arsenate (CCA) Wood Treatment for Utility Poles (6/8/2026)

CCA-treated poles have historically demonstrated long-term durability in demanding environments, including regions with high moisture levels, insect activity and severe weather exposure. Copper Naphthenate is viewed as an environmentally acceptable alternative in certain applications and jurisdictions.

Article - June 8, 2026 By LarsonElectronics.com

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Copper Naphthenate vs Chromated Copper Arsenate (CCA) Wood Treatment for Utility Poles

Utility poles must be pressure-treated with preservatives that protect the wood from decay fungi, termites and other biological degradation. Two common preservative systems used for utility poles are Copper Naphthenate (CuN) and Chromated Copper Arsenate (CCA).

While both treatments provide effective protection, they differ in chemical composition, environmental considerations, performance characteristics and application requirements.

Chromated Copper Arsenate

CCA is a waterborne preservative consisting of copper, chromium and arsenic compounds. The copper acts as the fungicide, protecting the wood against decay. Arsenic provides insecticidal properties and resistance against termites and wood-boring insects, while chromium serves as a fixing agent that chemically bonds the preservative components to the wood fibers. After treatment, the preservative becomes insoluble within the wood structure, providing long-term protection against leaching and biological attack.

CCA-treated poles have historically demonstrated long-term durability in demanding environments, including regions with high moisture levels, insect activity and severe weather exposure.

Copper Naphthenate

Copper Naphthenate is an oil-borne preservative that uses copper as the active ingredient dissolved in petroleum-based carriers or other approved solvents. Unlike CCA, Copper Naphthenate does not contain arsenic or chromium. The copper component provides protection against fungal decay and many wood-destroying organisms while the oil-based carrier enhances penetration into the wood. Because it does not contain arsenic, Copper Naphthenate is viewed as an environmentally acceptable alternative in certain applications and jurisdictions.

Copper Naphthenate eliminates concerns associated with arsenic preservatives while still providing protection against decay. As a result, some utilities and pole owners prefer Copper Naphthenate-treated poles when environmental stewardship, worker exposure considerations or sustainability initiatives are project factors.