Avoid Arsenic Exposure from CCA-treated Wood

January 7, 2023

Before January 2002, most pressure treated wood used in decks, patio furniture, children’s playground equipment, benches and picnic tables was made with chromated copper arsenate (CCA). CCA, 22 percent pure arsenic (a potent carcinogen) combined with chromium and copper, was injected into wood at high pressure to prevent rot and insect damage. The arsenic migrates to the surface of treated wood, where it can be picked up on hands and then ingested by children. Arsenic can also contaminate the soil under and surrounding treated wood. Some CCA-treated wood has a green tint. Testing is the only way to know for certain if the wood around your home contains arsenic, so you can then protect your children from future arsenic exposure.

Here are tips to reduce your exposure to arsenic in CCA-treated wood:
1. Protect your children from the hazards of arsenic in pressure treated wood used in outdoor play sets. Make sure kids wash their hands after playing on playgrounds. Cover wood picnic tables with plastic-coated tablecloths or avoid using the tables-spread a blanket out in the grass instead. Food and drinking water should not have any contact with pressure treated wood.

2. Protect your children from exposure to arsenic in CCA-treated wood decks. Block access to areas below treated decks so that children and animals cannot enter — arsenic can leach out of treated wood and contaminate the soil underneath. Do not store any children’s toys under decks, either. Put a sheet or blanket on treated decks for young children to play on. Replace wood in high traffic areas and handrails with safer alternatives. W ipe feet on a doormat before going indoors from the deck, and wash children’s hands after they spend time on the deck.

3. Seal any arsenic-treated wood in your yard every six months. Sealing the surface with paint or a polyurethane coating will reduce the amount of arsenic that can escape. However, such coatings don’t trap arsenic for more than six months, according the Environmental Working Group. To be safe, apply sealants twice a year, especially in high traffic areas. No definitive tests show that oil-based products seal better than water-based ones. Since water-based paints and sealants contain fewer toxic solvents, we recommend these. Exterior latex paint is another good choice since it will show wear and tear — and the need for a new coat.

4. Use caution when working with CCA-treated lumber. Avoid sawing or sanding, which releases arsenic into the soil and air. If you must sand or saw, do so only outdoors with plenty of ventilation. DO NOT ALLOW CHILDREN TO ENTER OR STAY IN THE AREA! Wear dust masks, gloves, and protective clothing to decrease exposure to sawdust and wash all work clothes separately before wearing them again.

5. Take gentle care of CCA-treated wood. Don’t use acid washes and bleach or other oxidizing cleaners on CCA-treated wood, which can release arsenic and convert the chromium in CCA into a more toxic form, hexavalent chromium.

6. Properly dispose of pressure treated wood. Do not burn CCA-treated wood, as it will release the arsenic as smoke. Do not compost sawdust, chips or small wood scraps derived from treated wood. Treat CCA-treated wood as hazardous waste. Contact your local sanitation department for information on where to dispose of it.