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Chromated Copper Arsenate (CCA):
Questions & Answers: What You Need to Know About Wood Pressure Treated with Chromated Copper Arsenate (CCA)

CCA Table of Contents

Current as of February 12, 2002

Chromated Copper Arsenate (CCA) is a chemical mixture consisting of three pesticidal compounds (arsenic, chromium, and copper) registered for wood preservative uses. EPA is currently reassessing CCA as part of its ongoing reregistration program for older pesticides. Federal law directs EPA to periodically reevaluate older pesticides to ensure that they continue to meet current safety standards. We have updated this document to reflect recent changes to the status of the registration for CCA.

How is CCA used?

CCA is injected into wood by a process that uses high pressure to saturate wood products with the chemical. Only people who have received the proper safety training should use CCA to treat wood products. CCA is intended to protect wood from dry rot, fungi, molds, termites, and other pests that can threaten the integrity of wood products. CCA-treated wood is most commonly used in outdoor settings. Around the home, CCA-treated wood is commonly used for decks, walkways, fences, gazebos, boat docks, and playground equipment. Other common uses of CCA-treated wood include highway noise barriers, sign posts, utility posts, and retaining walls. On February 12, 2002, EPA announced a voluntary decision by industry to move consumer use of treated lumber products away from CCA pressure-treated wood by December 31, 2003, in favor of new alternative wood preservatives. As of January 1, 2004, EPA will not allow CCA products to be used to treat wood intended for most residential settings. For more information, see our new Question and Answer document: Manufacturers to Use New Wood Preservatives, Replacing Most Residential Uses of Chromated Copper Arsenate (CCA).

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What precautions should be taken when working with CCA-treated wood?

Excessive exposure to inorganic arsenic can be hazardous to your health. Certain activities can facilitate the release of inorganic arsenic, so people working with CCA-treated wood should take a number of precautions, as follows:

These precautions will reduce your exposure from inhaling or ingesting sawdust, protect your eyes from flying particles, and prevent exposure to toxic smoke and ash. For more suggestions on avoiding unnecessary exposure to CCA, the Agency has identified some Common Sense Tips. Before working with CCA-treated wood, always consult the Consumer Safety Information Sheet, which is also available in hard copy by calling 1-800-282-0600.

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How should you dispose of CCA-treated wood?

Homeowners should never burn CCA-treated wood or use it as compost or mulch. CCA-treated wood can be disposed of with regular municipal trash (i.e., municipal solid waste, not yard waste). Homeowners should contact the appropriate state and local agencies for further guidance on the disposal of CCA-treated wood.

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Does arsenic leach from treated wood products into soil? If so, what happens to it?

Published results of scientific studies suggest that arsenic, over time, slowly leaches from CCA-treated wood products. The amount and rate at which arsenic leaches, however, varies considerably depending on numerous factors, such as local climate, acidity of rain and soil, age of the wood product, and how much CCA was applied. Some chemicals may also be dislodged from the surface of the wood upon contact with the skin.

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Is arsenic present in the environment from other sources?

Arsenic is a chemical element and is a natural constituent of the Earth's crust. It occurs naturally in rocks and soil, water, air, and plants and animals. When in the natural environment, arsenic usually binds to other molecules, such as those found in soils, and does not tend to travel very far. The average concentration of arsenic in soils in the United States varies considerably. Arsenic can be released into the environment through natural occurrences such as volcanic activity, erosion of rocks, and forest fires, or through human actions. Agricultural practices, mining, and smelting also contribute to arsenic releases in the environment. Approximately 90 percent of industrial arsenic in the United States is currently used as a wood preservative, but it is also used in paints, dyes, metals, and semiconductors.

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What risks does arsenic pose to human health?

Arsenic is a known human carcinogen and is acutely toxic. When estimating the potential risks that a chemical may pose, one must consider two factors: toxicity and exposure. Toxicity is described as the harmful effects that the chemical may cause, which is often dependent on the amount or dose received. Exposure is the dose received, typically orally or through contact with the skin, or by inhaling, over a certain period of time. Thus, whether any risk of toxic effects exists is dependent on both toxicity and exposure. As part of our comprehensive reassessment, EPA is evaluating both the toxicity and the potential exposure to arsenic from CCA-treated wood in light of the most recent scientific studies, which will allow EPA to characterize the potential risks from CCA-treated wood. EPA expects to release its comprehensive risk assessment for public and scientific review in 2003.

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How should I use CCA-treated wood?

CCA-treated wood is used in a variety of outdoor structures. Many people have used CCA-treated wood for fences, posts, decks, and gazebos. It should not be used where routine contact with food or animal feed can occur. Do not use CCA-treated wood for cutting boards, counter tops, bee hives, compost, mulch, or structures or containers for storing human food or animal feed. Furthermore, since some animals like to eat wood, CCA-treated wood should not be used where animals can chew on the treated wood. Also, do not use where treated wood may come into direct or indirect contact with drinking water, except for uses involving incidental contact with docks or bridges. On February 12, 2002, EPA announced a voluntary decision by industry to move consumer use of treated lumber products away from CCA pressure-treated wood by December 31, 2003, in favor of new alternative wood preservatives. As of January 1, 2004, EPA will not allow CCA products to be used to treat wood intended for most residential settings. For more information, see our new Question and Answer document: Manufacturers to Use New Wood Preservatives, Replacing Most Residential Uses of Chromated Copper Arsenate (CCA).

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Are there alternatives to using CCA-treated wood?

A number of preservatives have been registered by EPA, and wood treated with these preservatives are expected to be available in the marketplace. In addition, untreated wood (e.g., cedar and redwood) and nonwood alternatives, such as plastics, metal, and composite materials, are available. Your local hardware store or lumberyard can provide more information on available alternatives.

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What advice does EPA have for consumers who believe they have suffered an adverse reaction from CCA-treated wood?

If you feel you are suffering possible adverse effects from working with CCA-treated wood, you should immediately contact your medical provider. For further information, and to report incidents to the EPA, please contact the National Pesticide Information Center at 1-800-858-7378 Exit EPA disclaimer .

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What is EPA doing to assess the safety of CCA-treated wood?

EPA is currently reviewing the use of CCA-treated wood in light of the latest science and safety standards under the Agency's reregistration program. Throughout this transition process (see Manufacturers to Use New Wood Preservatives site), we have continued working on our risk assessment and the Agency is continuing to proceed with a risk assessment. Through our risk assessment process to date, we have received extensive recommendations from the Scientific Advisory Panel (SAP), a group of scientific experts, on the best approach to evaluating potential risks to children from exposure to decks and play-structures. Visit the SAP Report for more information. We have also received many comments from the public, stakeholders, industry, and public interest groups and we will review these comments as we determine the next steps.

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