Wood treatment linked to
by Don Hopey,
Post-Gazette Staff Writer
reprinted from the Pittsburgh Post-Gazette
January 25, 1998 edition
A forester in Indiana got
deathly sick sawing pressure-treated wood to build picnic tables.
Three quarterhorses in Clay County, Fla., fell ill after
cribbing or biting repeatedly on a pressure-treated wood
fence. Two died.
You could pick up more than just a splinter from the chemically
impregnated wood widely used to build backyard decks, playground
equipment, picnic tables, lawn furniture, fences, gazebos, and boat
The dense, gray-green wood can make you sick, pollute the
environment and isnt as durable as the treated wood industry
claims, said Edward Polaski, who compiled a review of research on
pressure-treated wood for the state Department of Conservation and
My report should be a wake-up call, said Polaski, who
until recently worked for the department as a wood use adviser.
Certainly use of this wood needs more study.
According to Polaskis research, chromate-copper-arsenate, or
CCA, the highly toxic chemical pesticide widely used as a wood
preservative, can seep out of the wood. Those cancer-causing chemicals
could pose a health concern and an environmental threat during the
woods useful life and after its disposal.
Polaski thinks the CCA-treated wood - comprising more than 90
percent of the $2.5 billion a year treated wood market - should be banned
or its use severely restricted to areas where people wont regularly
But the state Department of Conservation and Natural Resources, the
agency that ordered the report, believes Polaski overstates the dangers
from CCA-treated wood. The U.S. Forest Service, not to mention the wood
industry, is similarly skeptical. And the U.S. Environmental Protection
Agency says it is reasonably safe if used appropriately.
But Polaski is not alone in his concerns.
I dont think his conclusions are overstated. Its
better to be concerned and conservative before you make the mistake of
introducing arsenic into the environment, said Dr. Garn Wallace, a
biochemist at Wallace Laboratory, in El Segundo, Calif. The private lab
specializes in plant nutrition, soil composition testing and heavy metals
Wallace said liquid oozing from CCA-treated wood could contaminate
ground water under porous-sandy soils and produce a host of health
problems in humans, from liver and kidney failure to cancers.
Wallaces studies show arsenic from CCA-treated wood stunts
plant growth and turns leaves yellow. Vegetables grown in soil with an
elevated arsenic level can contain high arsenic levels themselves. At
playgrounds with CCA-treated wood equipment, Wallace has found soil
samples showing 10, 20, even 100 times the background level of arsenic in
Its obvious from the studies that the growth of
herbaceous plants is injured in the presence of CCA-treated wood,
he said. I dont know at what levels injuries to people will
occur, but there is a plausible risk factor.
The treated wood industry denies there is a risk if the wood is
handled and used properly, and maintains CCA is a safe preservative
suitable for structural uses around homes, and in parks and playgrounds.
There is a 60-year history of CCA in the United States where
it has been used successfully, said Allan Wilbur, a spokesman for
the American Wood Preservers Institute. Of the 160,000 playground
accidents that occur annually, none are related to the leaching of those
But a growing number of court cases and jury verdicts have blamed
the chemicals for causing harm.
In one case, James Sipes, a U.S. Forest Service worker in the
Hoosier National Forest in Indiana, was saw CCA-treated wood to build
picnic tables one spring when he got so sick that he vomited up half the
blood in his body.
Doctors didnt identify the cause of his problem until he went
back to work. The next spring he was given the same job and he started
vomiting blood again. A jury said the chemicals in the wood caused the
problems and awarded him $100,000. Twenty-six companies involved with
production and supply of the chemicals and wood settled out of court,
paying Sipes $667,200.
The problem with CCA exposure is that you cant show a
history, you could have people getting ill and thinking its any
number of things - arthritis, the flu, said David McCray, an
Indiana lawyer who has won three claims involving injuries from
The effects of CCA exposure can be insidious and can range
from hair loss, to itching skin, bleeding, nerve damage. Chemical
exposure health problems are difficult to pinpoint and can mimic many
Polaskis report on CCA-treated wood, and another one critical
of the state Bureau of Forestrys fledgling Timber Bridge Program,
were done when he worked for the state.
The bridge program, developed to promote use of Pennsylvania
hardwoods for small bridge projects, uses the preservative creosote,
which is toxic to humans.
The DCNR has disowned both reviews, initiated by Polaski in the
early 1990s with the approval of James C. Nelson, then
Pennsylvanias state forester, to determine if CCA-treated wood is
safe. The first draft of the CCA-treated wood review wasnt
completed until June 1994, after James Grace became state forester.
Grace asked the U.S. Forest Service to critique Polaskis CCA
review. In August 1994, Thomas Hamilton, director of the Forest
Services Forest Products Laboratory, wrote to Grace saying that
although there are some legitimate concerns about the use of
CCA-treated wood, [Polaski] overstates the literature and makes
assumptions that are not supported by scientific fact.
The Forest Service had negative comments and no one has told
us his research is valid, said Gretchen Leslie, a DCNR
Polaski was fired from the Forestry Bureau job he had held since
1981 in August, four months before his retirement. Polaski said he was
let go because of his work on the reports and resulting pressure from the
wood products industry, a charge the state denies.
Polaskis CCA-treated wood report cited studies showing 20
percent, 30 percent, even more than 50 percent of the chemical can
leach out of the wood. Much of the problem is caused by
impure or improperly applied chemicals used in the wood treatment
process, causing incomplete fixing of the chemicals within
Studies also show that exposure to acidic rainfall increases the
risk of chemical leaching. Given the acid rainfall in our
state, Polaski said, the amount of these toxic CCA chemicals
leached may increase over time. Determining the actual leaching
rate, however, will require studies of lumber stockpiles and of wood sent
to landfills, he added.
Samuel Rotenberg, a toxicologist at the EPAs Philadelphia
regional office, said the chemical do leach from the wood, but there have
been no studies of production conditions and their effects on leaching
He warned that individuals who cut, saw, or sand the wood can be
exposed to high levels of toxic chemicals and should protect themselves
by wearing a breathing filter over their noses and mouths.
As far as using a boardwalk or deck built from CCA wood, I
dont think that would present an unreasonable risk, Rotenberg
said. But I would not build a childrens sandbox out of the
stuff because arsenic can leach into the sand and be eaten by children. I
also wouldnt build a sandbox under such a deck because we know now
that there can be increased arsenic levels in those areas from sawdust
produced during construction.
Polaski said the high volume of treated wood produced increases
potential hazards. More than 50 billion board feet of chemically treated
wood has been produced over the last decade at 550 different production
plants. About 17 percent of all softwood lumber is pressure-treated
Each year, commercial wood treatment infused wood with 137.5 million
pounds of chemicals.
John Hall, a spokesman for the American Wood Preservers Association,
said that while there are more than 90 standards governing the wood
preservative industry and treatment processes, there are none setting
acceptable CCA leaching levels.
There are no standards that specify a level for minimal or
maximum migration of chemical pesticides from wood, Hall said.
Those studies that show a high rate, well, 40 or 50 percent sounds
CCA-treated wood, first used in India in 1933 and approved by the
American Wood Preservers Association for use by Bell Telephone Co. in
1950, is resistant to insect infestation and rot. The copper and arsenic
are fungicides and insecticides. The chromium is primarily a
fixing agent, bonding the chemicals to the wood.
Older wood preservatives - penta or pentachlorphenal and
creosote - pose considerable health risks to users of the wood, but
CCA-treated wood is supposed to be safer in part because the toxins are
fixed in the wood.
The raw lumber is placed in a pressure cylinder where a vacuum sucks
air and water from the wood cells. The cylinders is then filled with a
mix of water and pesticides and pressure is increased to refill the
woods cells with the mixture. As the wood dries, the chemicals are
Arsenic and chromium are carcinogens and mutagens, according to the
EPA and the Occupational Safety and Health Administration. Exposure can
occur through breathing or through repeated skin contact. High or
repeated exposure can cause cancer, fetal toxicity and birth defects,
neurotoxicity, including paralysis, warty skin growths, and liver and
Nevertheless, the EPA has certified that CCA-treated wood does
not pose unreasonable risks to children or adults exposed to the
wood or surrounding soils, based on tests of laboratory prepared wood
samples conducted in the 1980s.
However, in 1988 the agency was concerned enough about the effects
on workers who come in contact with CCA on a daily basis that it required
protective clothing and respirators to reduce their exposure.
Polaski said the EPAs CCA certification tests were invalid
because they dont reflect real and disparate commercial
manufacturing conditions. Production of environmentally safe, CCA-treated
products involve complex chemical reactions that can be compromised in
commercial production, resulting in less than complete chemical
fixing and increased leaching.
Wilbur concedes that CCA leaching does occur, and it happens more
when treatment standards arent followed.
As in any product line, there are good and not so good
manufacturers, so [Polaski] has a point, Wilbur said. There
may be folks that take shortcuts. Thats not appropriate, and we do
not condone that, but we have no policing powers.
Polaskis CCA research review draws on a number of leaching
studies. Among them:
- A 1994 study at the University of Turin in Italy found exposure of
CCA-treated wood sawdust to rain water resulted in significant release of
the chemicals and was potentially hazardous.
- A 1984 study of the biological impact of CCA-treated wood on
honeybees found that the bees had elevated arsenic levels and poorer
winter survival when kept in CCA-treated hives.
- A 1991 study by researchers at Rutgers University found leaching
of CCA-treated wood in to sea water retarded the growth of fiddler crabs
and algae, and resulted in higher death rates for fish and snails.
- The leaching research of David E. Stilwell, an analytic chemist at
the Connecticut Agricultural Experiment Station of New Haven, Conn.,
found elevated levels of copper, chromium and arsenic in soil samples
under seven wood decks built with CCA-treated wood.
Stilwells 85 soil samples showed arsenic levels two to four
times greater than allowable standards, and showed signs of increasing
over time. That could harm yard and garden plants.
A playground exposure study he is working on isnt finished,
but thus far indicates that use of CCA-treated wood should be avoided
wherever possible in the playground, especially on surfaces children
If alternative materials are available, Stilwell
said, why not use them and remove toxic materials away from
He said sealing the deck or playground equipment retards leaching
and minimizes the amount of arsenic that is picked up by contact. It
would be even better to replace or cover handrails and play equipment
with plastic or a wood-polymer composite like Trex.
His view is supported by the California Health Department, which
recommends that play surfaces of recreational equipment be coated every
two years with an outdoor-grade polyurethane sealant.
Stilwell also questioned why the EPA requires risk warning stickers
of CCA-treated lumber, but not on products such as picnic tables or
playground equipment manufactured from the wood.
There is always the benefit vs. risk question to be answered
in these situations and that got lost in the promotion of CCA-treated
wood, Stilwell said. Its now being promoted for
applications beyond its original scope, and some of those are not a good
Stilwell concedes that the longer life of CCA-treated wood is
reducing pressure to cut endangered trees, such as redwoods. But he said
treated wood should either be sealed better or treated with safer
One of the biggest selling points for CCA is that it extends the
life of wood, saving billions in both dollars and trees.
More than 90 percent of treated wood is yellow southern pine.
Without preservative treatment, the wood would only last one to three
years, Wilbur said. Wood properly treated with CCA can last 10, 20, even
Polaski found, however, that the preservation chemicals sometimes
weaken southern soft woods and shorten their lifespans.
The woods structural integrity is attacked by the
preservative chemicals, probably the acid in the treating
solutions, he said. Thats weakening the wood, and
certainly, given that many of these decks are built high, creating the
potential for disaster if they break.
Although he admits there are few reports of decks collapsing,
Polaski said many built a decade ago are showing signs of decay and
should be inspected.
Wed have to look at that on an individual basis,
said Wilbur, the industry spokesman, but 99 percent of the deck
failures weve seen are due to improper construction, not wood
Disposal and burning of the treated wood creates other problems.
If the treated wood catches fire, Polaski says, smoke from the
combustion would contain copious amounts of poisonous
chemicals. Residual ashes would contain hazardous chemicals that
could be absorbed through the skin or leach through soil to contaminate
In December, Wisconsins environmental agency fined John
Menard, owner of the 200-store Menards home improvement chain, $1.7
million for burning CCA scraps to heat the companys lumber
production facility. Menard was caught carting the ash from that facility
to his home, where his disposed of it with the family trash.
In Minnesota, 22 cows were killed when a farmer spread fireplace
ashes from CCA-treated wood in the field where they were grazing.
Polaskis review cites two incidents, reported in 1988 and 1990
newspaper articles, of people harmed by using treated wood for fuel. In
both cases, the people developed neurological problems, numbness in the
arms and legs, loss of hair, skin rashes and gastrointestinal upsets.
Burning any of the wood in a fireplace or outside is a bad
thought, and presents a clear exposure route to toxic chemicals that
should absolutely be avoided, the EPAs Rotenberg said.
Despite government and manufacturers warnings, the dangers
associated with burning CCA wood still arent widely known,
according to Keith Solomon, a toxicologist at the University of Guelph in
Ontario, Canada. His research found that acid rain caused the chemicals
to quickly wash out of the wood.
The public should be better informed, he said.
While camping, I watched a family at a nearby campsite build a fire
with scraps of the stuff. The blue-green flames produced by the chemicals
were very attractive, but the kids were cooking hot dogs in the smoke.
Not a good idea.
The recommended method of disposing of construction scraps is by
placing them in the trash and taking them to a landfill. That works for
now, but what happens over the next several decades, as the decks, fences
and docks built in the 1970s and 1980s are replaced and the old wood is
sent to landfills?
Based on a 30-year service life, a study by the Forest Products
Laboratory in Madison, Wis., estimated that 2.5 billion board feet of
treated wood are entering the waste stream today. That will increase to 8
billion board feet by the year 2020.
Landfills owned by Minnesota have already stopped taking CCA-treated
wood scraps because of concerns about chemical leaching and water
We believe there will be a tremendous problem with CCA
disposal in the future. Landfills dont want EPA-listed hazardous
chemicals or know carcinogens, said Pat Bischel, president of
Northern Crossarm Co., a Wisconsin treated-wood producer.
Northern Crossarm last fall stopped making and distributing
CCA-treated wood. Instead, Bischels firm is now using ACQ -
ammoniacal copper quaternary - which contains no hazardous chemicals.
Polaskis report identifies several safer alternatives,
including borate-treated wood, which has been used in Australia and
several other countries since the 1940s for bridges, home decking and
playground equipment. A half-dozen CCA pressure-treating plants in Hawaii
have converted to borates.
Northern Crossarm, Rhode Island-based BB&S, Treated Lumber of
New England, and six other wood treatment companies have switched or are
switching from CCA to ACQ, a chemical compound produced by Chemical
Specialties Inc., one of the nations major producers of CCA.
I believe we will see a transformation of the treated wood
industry and within a few years the majority of treatments will use an
alternative to CCA, Bischel said. CCA wont be outlawed,
but like creosote and penta will be in decline. And like those two
treatments, the switch from CCA will be consumer driven.
Germany banned CCA lumber in the mid-1970s, substituting wood
treated with chromium, copper and fluoride. In 1994, New Jersey
restricted use of CCA-treated wood in some marine construction to prevent
contamination of shellfish beds.
Environmental Building News and the American Institute of Architects
both recently recommended that builders consider CCA alternatives.
The nations three major producers of CCA have developed their
own copper-based alternatives to CCA, each eliminating the most toxic
components of arsenic and chromium.
Polaski said a re-evaluation of the safety of pressure-treated
lumber by federal and state agencies would hasten the switch to
My intent in compiling information on CCA and related
hazardous wood preservatives is not to condemn wood preservatives in
general, he said. I hope through my efforts, I will encourage
the development of reliable, safe wood preservatives.
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