According to MarketWatch’s September 15, 2021 press release, the size of the global chromated copper arsenate (CCA) market will decrease to $53 million US by 2026 – down from $58 million this year. While CCA preservative was voluntarily withdrawn by manufacturers for residential use in the United States in 2003, it is still in high demand for treating wood and lumber used in industrial settings and agricultural applications.
What Is CCA?
Chromated copper arsenate is a water-borne solution, invented in 1933 by Dr. Sonti Kamesam. It has been used extensively to impregnate wood products – specifically those planned for outdoor use or ground contact – to protect against microbes, fungi, termites and other insects that degrade or threaten the integrity of wood. Copper is toxic to the fungi that cause rot; arsenic is a common insecticide; and chromium is the chemical fixing agent. CCA imparts a greenish tint to the treated wood and does not adversely affect the texture and grain of the lumber. There are some exceptions like Wolmanized® wood – which is scientifically formulated to look like regular lumber with no greenish tint, although it is still treated with CCA. With “pressure-treated wood,” CCA is injected into the lumber employing a process that uses high pressure to force the chemical into the wood’s pores, saturating the wood product. CCA-treated wood was praised in the early 1940s for extending the service life of lumber and decreasing the harvesting of trees.
Where Is CCA Found?
Most wood used for outdoor children’s playsets, picnic tables, gazebos, fences, walkways, boat docks and decks between 1975 and 2003 in the United States was treated with chromated copper arsenate. In 2002, the U.S. Environmental Protection Agency (EPA) announced that manufacturers voluntarily agreed to discontinue the use of CCA-treated wood products for homeowner applications; but it is still available primarily for industrial use. Effective January 1, 2004, CCA was no longer produced for use in residential settings; but stores were permitted to sell their existing stocks of CCA-treated wood and EPA did not require the removal of built structures containing CCA. Also, retailers were required to display a warning label in places where CCA-treated wood is sold.
Exposure to CCA
The main reason CCA affects human health and the environment is the arsenic in CCA-treated wood. Arsenic was designated as a human carcinogen by EPA in 1986 – known to cause skin, lung, liver, kidney, prostate, and bladder cancer. People may be chronically exposed to the arsenic (medically known as arsenicism) found in CCA-treated lumber by absorption through the skin, inhalation of dust during sawing/sanding, drinking contaminated well water, or hand-to-mouth contact after touching the-treated wood. Gastrointestinal symptoms of arsenic poisoning – both short-term high-dose and long-term low-dose – include vomiting blood, nausea, abdominal pain, and diarrhea. There is currently no antidote for arsenic poisoning; but two chelation therapies are available in the U.S.
Improperly sealed CCA-treated wood releases small amounts of arsenic and has the potential to contaminate the soils around or below the wood; so exposure through aerosolized soil is also common. Acute, deadly exposure to arsenic can take place while burning CCA-treated wood – releasing copper, arsenic and chromium into the air. Even the ashes of this burned wood are hazardous to livestock or wildlife. Therefore, it is illegal to burn CCA-treated wood in all 50 states.
Minimizing CCA Exposure
Several guidelines can be followed to minimize exposure to CCA in pressure-treated wood/lumber:
- Personnel handling CCA-treated wood and lumber should wear dust masks, protective clothing, and gloves – according to the recommendations of the Agency for Toxic Substances and Disease Registry (ATSDR).
- Structures made of CCA-treated wood/lumber should be coated with a commercially-available sealant that will minimize leaching of arsenic, chromium and copper.
- CCA-treated wood and lumber should not be used as mulch or wood chips, or put in a composting pile.
- Children playing on playground equipment or decks constructed with CCA-treated wood/lumber should thoroughly wash their hands with soap and water after playing and avoid hand-to-mouth activities during play.
- Pressure-washing CCA-treated wood and lumber should be avoided.
- Vegetables grown within 15 inches of CCA-treated wood/lumber raised beds may be a health concern.
Most state and local governments have detailed guidelines, regulations and requirements for disposal of CCA-treated wood and lumber waste – normally in lined landfills under the jurisdiction of the state/local solid waste management authority.
Alkaline copper quaternary (ACQ), with its greenish-brown color, is currently one of the most widely-used residential wood preservatives that does not contain arsenic or chromium. Other new materials used to build outdoor structures today include cedar (naturally rot-resistant), plastic lumber (made of PVC), composite lumber or engineered wood (a mixture of wood fiber, plastic and binding agents) and metal.
CCA Exposure Monitoring and Mitigation Services from HETI
The majority of the CCA pressure-treated wood and lumber installed as far back as the 1940s is still in use today and in good condition. HETI has the staff of environmental health & safety professionals that can assist in identifying and evaluating the condition of CCA pressure-treated wood/lumber, including testing the surrounding soil for contamination from nearby structures. HETI can also help with providing disposal options for any CCA pressure-treated wood and lumber.
References:
Global Chromated Copper Arsenate Market to Witness a Pronounce Growth During 2025, https://www.marketwatch.com/press-release/chromated-copper-arsenate-market-insights-with-statistics-future-prospects-and-witness-a-pronounce-growth-during-2026-2021-09-15?tesla=y
Chromated Copper Arsenate (CCA), U.S. Environmental Protection Agency
CCA-Treated Wood Used in Playground Equipment, Consumer Product Safety Commission
Inorganic Arsenical Pressure-Treated Wood, EPA Office of Pesticide Programs
Morais S, Fonseca HMAC, Oliveira SMR, et al; Environmental and Health Hazards of Chromated Copper Arsenate-Treated Wood: A Review; International Journal of Environmental Research and Public Health, 2021; 18(11):5518, published 2021 May 21. doi:10.3390/ijerph18115518
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