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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?
What precautions should be taken when working with CCA-treated wood?
How should you dispose of CCA-treated wood?
Does arsenic leach from treated wood products into soil? If so, what happens to it?
Is arsenic present in the environment from other sources?
What risks does arsenic pose to human health?
How should I use CCA-treated wood?
Are there alternatives to using CCA -treated wood?
What advice does EPA have for consumers who believe they have suffered an
adverse reaction
from CCA-treated wood?
What is EPA doing to assess the safety of CCA-treated wood?
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).
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:
- Saw, sand, and machine CCA-treated wood outdoors. Wear a dust mask, goggles, and gloves.
- Clean up
all sawdust, scraps, and other construction debris thoroughly and dispose
of in the trash
(i.e., municipal solid waste). Do not compost or mulch
sawdust or remnants from CCA-treated wood.
- Do not burn CCA-treated wood, as toxic chemicals may be released as part of the smoke and ashes.
- After working
with the wood, wash all exposed areas of your body, especially the hands,
thoroughly
with soap and water before eating, drinking, toileting, or
using tobacco products.
- Wash your work clothes separately from other household clothing before wearing them again.
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 at 1-800-282-0600.
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.
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.
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.
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.
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).
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.
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.
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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August 30, 2002