The Poisonwood Rivals

A report on the dangers of touching arsenic treated wood

Thursday, November 1, 2001

The Poisonwood Rivals

A report on the dangers of touching arsenic treated wood

View and Download the report here: The Poisonwood Rivals

Nationwide sampling by a coalition of public interest groups* found dangerous levels of arsenic on the surface of “pressure treated” wood purchased at The Home Depot and Lowe’s Home Improvement Warehouse. These twin giants of the home improvement industry aggressively promote their concern for the environment, but they stack their shelves with highly hazardous lumber infused with the arsenic-containing pesticide CCA.

Arsenic treated lumber is used to build more than 90 percent of all outdoor wooden structures in the United States. The standard formulation of CCA used in wood is 22 percent arsenic. In our national testing program unsafe amounts of arsenic were easily wiped off the surface of all treated wood purchased from Home Depot and Lowe’s stores in 13 metro areas.

Measured amounts ranged from 18 to 1,020 micrograms (μg) on a 100 square centimeter (cm2) surface, about the size of a single handprint of an average four-year-old child. This is considerably more arsenic than the Environmental Protection Agency’s (EPA’s) proposed 10 μg per day allow- able exposure level for arsenic in drinking water.** Based on these data and the results of numerous government and academic studies, we estimate that one out of every 500 children who regularly play on swing sets and decks made from arsenic treated wood, or one child in an average size elementary school, will develop lung or bladder cancer later in life as a result of these exposures (EWG 2001).

Arsenic sticks to children’s hands when they play on treated wood, and is absorbed through the skin and ingested when they put their hands in their mouths. Our test was designed to mimic a small child’s hand coming into routine contact with the wood surface, and involves swiping the wood with a slightly moistened polyester wipe, then testing the wipe for arsenic.

Arsenic treated lumber can significantly compound risks from arsenic contaminated drinking water. In its latest examination of arsenic toxicity, the National Academy of Sciences’ (NASs’) National Research Council found that long-term arsenic exposures at EPA’s proposed 10 micrograms a day translate into a 1 in 300 risk of lung or bladder cancer (NRC 2001). On average, our samplers easily wiped 25 times this amount (247 micrograms of arsenic) off the surface of arsenic treated lumber from Home Depot or Lowe’s, in an area the size of a four-year-old’s hand. (Figure 1, Table 1, and Table 2).

Arsenic is a known human carcinogen that has come under increasing regulatory scrutiny in the past year. In January 2001, the Bush Administration delayed more protective regulations for arsenic in drinking water pending another in a long series of reviews of arsenic toxicity by the National Research Council (NRC). In its new 2001 review, the NRC found that the most recent studies show arsenic to be even more toxic than previously thought (NRC 2001). The Consumer Product Safety Commission is conducting a formal review of the safety of arsenic treated wood for children’s play structures, and the EPA is in the midst of an expedited review of the cancer risks that arsenic treated wood presents to children.

In an effort to fend off a ban on CCA, Home Depot and Lowes worked closely with the treated wood manufacturers to win EPA approval of a new, voluntary consumer information program. Citizens in this testing program purchased arsenic treated wood at 13 Home Depot’s and 5 Lowes retail outlets in 13 states and not a single individual was offered any safey information. Even if they had been, the information from these retailers says nothing about the risk to the public and particularly children who routinely contact structures made with arsenic treated wood. Retailers claim that their consumer information sheets will be more prominently displayed beginning this fall.

How dangerous is arsenic?

Arsenic is on EPA’s very short list of chemicals known without question to cause cancer in humans. The National Academy of Sciences (NAS) and its National Research Council, which have now produced seven reports addressing arsenic, have concluded multiple times that arsenic causes lung, bladder, and skin cancer in humans, and may also cause other cancers including kidney, prostate, and nasal passage cancer. NAS and EPA’s Science Advisory Board (SAB) also have concluded that arsenic may cause high blood pressure, cardiovascular disease, and diabetes.

All other uses of arsenic as a pesticide are banned by the EPA. But under a special federal exemption, millions of pounds of CCA a year are injected into wood that is then sold to families all across the country. CCA is not only poisonous to pests, but also to children. This study confirms the findings of virtually all research conducted in the past 15 years, which shows that significant amounts of arsenic are found on the surface of pressure treated wood and that this arsenic is readily rubbed onto clothes and skin. As our own report Poisoned Playground shows (EWG and HBN 2001), unsafe levels of arsenic remain on the surface of arsenic treated wood after more than 15 years of outdoor exposure and use.

Hypocrisy of Home Depot and Lowe’s

This year the wood treatment industry acknowledged the failure of its voluntary consumer information program, and blamed retailers like Home Depot and Lowe’s for failing to properly inform customers about the risks of arsenic treated wood. In response to growing concerns about the hazards of arsenic treated wood, the wood treatment industry announced changes to the program. These changes fail to address the the two fundamental flaws in the program.

First, the program relies on voluntary efforts of thousands of home improvement retail stores to educate their staff nationwide on the content of the program and to ensure that the safety information is passed out to each and every customer who purchases the wood. According to both the wood industry and EPA, a similar program initiated in 1986 completely failed. During our retail sampling program, none of 18 stores tested offered our samplers any consumer information on arsenic treated lumber.

Second, the “safe” handling information on the consumer sheets advises those building with and sawing the wood to wear face masks and gloves, but provides no precautions whatsoever to protect children who often play or even eat on the arsenic treated wood surfaces, sometimes beginning the very minute construction is finished.

The safety information on the consumer information sheets stands in stark contrast to the detailed safety information provided to workers in the chemical industry and wood treatment industry who handle the arsenic wood preservative CCA in the workplace. Under the federal Occupational Safety and Health Act of 1970, these workers are provided health and safety information in a lengthy document called the Material Safety Data Sheet, or MSDS. Among the warnings on the MSDS for CCA are:

  • 2.5 ounces of treated wood dust ingested by a small child may be life threatening
  • Avoid frequent or prolonged contact with the skin.
  • This product should not come in contact with food or feed.

Instead, at many Home Depot and Lowe’s, customers can take home “CCA FACTS,” a full-color promotional brochure from a leading arsenic chemical manufacturer (Osmose Wood Preserving Inc) declaring:


One of the Home Depot stores visited by a tester in Grand Rapids, Michigan displayed a giant sign declaring “CCA Treated Lumber is Safe!”, yet a recent Home Depot circular pushed plastic fencing as an “enviromentally friendly” alternative with “no arsenic, creosote, etc. which can be harmful to children and animals.” (see Figure 3, page 37). These competing, misleading and inherently conflicting advertisements leave children at risk.


  • Arsenic treated lumber is unsafe, particularly for children, and The Home Depot, Lowe’s Home Improvement Warehouse, and all other retailers should stop selling it. These retailers, many of whom tout their environmental responsibility, continue to sell a product that exposes American families to high levels of arsenic, a known carcinogen.
  • We urge consumers to demand alternatives when they visit their local home improvement centers. Safe alternatives are plentiful, from wood treated with less toxic preservatives, to cedar which resists rotting naturally, to other materials like recycled plastics or metal.
  • EPA must ban arsenic-containing pesticides for sale as a wood treatment pesticide, and the CPSC must ban all consumer products made with wood preserved with arsenic-containing pesticides.
  • Homeowners should replace their arsenic treated decks, swing sets and picnic tables with safe alternatives. If the structures are not replaced, homeowners should seal the wood at least once a year. Anyone who contacts arsenic treated wood should wash their hands afterwards, particularly before eating. Children’s toys should not be stored under decks, because arsenic leaches off the wood when it rains and could coat the toys. Parents and pet owners should keep children and animals away from the dirt beneath and immediately surrounding arsenic treated wood structures. Arsenic treated picnic tables should be avoided, but if used should be covered with a table cloth.

View and Download the report here: The Poisonwood Rivals

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