May 6 2002

Results from new cutting-edge research on the hazards of CCA wood were presented at the latest meeting of the CCA Technical Advisory Group, held today at the University of Florida in Gainesville. CCA is a controversial toxic and carcinogenic compound, also known as Chromated Copper Arsenate, which is used to treat wood to prevent insects and fungi. Some of these new findings about CCA-treated wood were both profound and shocking.

The meeting, sponsored by the University of Miami and UF’s Center for Solid and Hazardous Waste Management, was attended by variety of interested parties, including representatives from the treated wood industry, Florida Power and Light, Florida Department of Environmental Protection, reporters from the St. Petersburg Times, Gainesville Sun, and BANCCA.ORG, as well as attorneys from legal firms filing upcoming class action lawsuits against the CCA wood industry.

Speakers presented results from several new studies on the hazards and problems associated with CCA-treated wood. The speakers included Dr. Helena Solo-Gabrielle from the University of Miami, Dr. Tim Townsend from the University of Florida, John Schert from the Center for Solid and Hazardous Waste Management, and Bill Hinkley, Director of the Florida Department of Environmental Protection in Tallahassee.

The results of the new research presented at the meeting revealed some disturbing facts:

• Calculations show that a "mountain" of CCA will be disposed of in Florida in the near future, reaching a peak of 32 million cubic feet by 2012 before beginning to taper off, even in spite of the upcoming ban on sales of CCA wood.

• The cumulative amount of arsenic introduced into Florida by CCA wood is 31,000 tons. Dr. Solo-Gabrielle explained that "this amount of arsenic would pollute enough water to fill 590 Lake Okeechobees!" [Note: this amount of arsenic would raise an amount of water equivalent to 4.83 X 1012 Liters to 10 micrograms arsenic per Liter, which is the maximum level of arsenic by current Federal drinking water standards.] She explained further that if this same amount of arsenic were converted to granular form, "it would fill an area the size of a football field (100 yards by 50 yards) to a height of 63 feet."

• Side-by-side analyses of commonly available CCA alternative chemicals show that these CCA alternatives are also far from perfect, as both ACQ (Ammonium Copper Quaternary), CBA (Copper Boron Azole) and CC (Copper Citrate) leach significantly higher levels of copper than CCA. For example, ACQ leaches approximately 28% of its copper mass, versus 7% for CCA. This presents problems because copper is considered a "potent aquatic biocide" that is harmful to marine life. However, the relative risks are much higher for CCA, especially where humans are concerned.

• An arsenic "speciation" study of CCA wood revealed a fascinating new fact. CCA wood can contain both forms of arsenic- arsenate (As V), which is moderately toxic and carcinogenic, as well as arsenite (As III), which is highly toxic and carcinogenic. In tests of new CCA wood, only arsenate was found, but used or "weathered" wood revealed high levels of both the highly toxic arsenite, as well as levels of arsenate. Prior to this study, it was presumed that "weathered" CCA wood, (wood that had been exposed to the elements for greater than 10 years), would be less toxic due to leaching. This new data revealed the opposite, however. Weathered wood is even more toxic in some ways that new CCA-treated wood- for reasons as yet unknown. This can only spell trouble for homeowners who might be considering dismantling their older CCA decks.

• Findings from the chromium speciation studies of CCA-treated wood showed surprises as well. First, some background: it is important to understand that there are three kinds of chromium: elemental chromium, which is found in vitamin tablets, trivalent chromium, which is considered mildly toxic, and hexavalent chromium, made infamous by the movie "Erin Brockovich", which is known to be both highly toxic and carcinogenic.

In the past, many industry experts have stated that all of the chromium found in CCA-treated wood is trivalent chromium (Cr III), and is therefore not hazardous. This distinction is important when it comes to regulations regarding CCA wood and whether it should be treated as a hazardous waste.

However, the new data revealed at the TAG meeting by Dr. Townsend showed that a small amount of hexavalent chromium is present in ordinary CCA wood samples, and that more hexavalent chromium is formed when the CCA treated wood is exposed to alkaline conditions (pH of 8-13). In a highly alkaline condition, ALL of the chromium leached from the wood is converted to the more toxic form of hexavalent chromium.

Moreover, during tests of the combustion (burning) of CCA wood in test furnaces, ALL of the chromium released from 0.25 pcf treated CCA wood was toxic hexavalent chromium (Cr VI). This is the same type of CCA wood commonly used in residential applications for decking boards, and is widely available. This new finding may force the re-classification of CCA wood to hazardous waste by some environmental regulatory agencies.

Further findings revealed today at the CCA TAG meeting included these:

• 80% of samples of new CCA-treated wood failed the standard TCLP test for toxicity.

• Ash from furnaces with as little as 5% CCA wood combusted fail standard tests for hazardous waste.

• Mulch made from recycled wood that includes as little as 1% CCA leaches arsenic in excess of the current MCL test standard of 50 microgram/Liter. It is also hard to determine if the recycled wood mulch contains CCA wood, since most mulch is dyed red with iron oxide, disgusing the CCA wood chips within it. Bill Hinkley of Florida DEP stated that his office has advised producers of recycled mulch that "they should not be making mulch out of CCA. People think they're doing the right thing by using recycled wood mulch, only to find out otherwise...".

• Since CCA sawdust is considered highly toxic, this sawdust may not be included in the RCRA exemption in the future. This would mean that CCA sawdust would have to be treated as a hazardous waste and disposed of in a manner appropriate for hazardous waste. This requirement, if implemented, would affect businesses who make products from CCA wood.

• Due to problems from CCA leachate, in the future CCA may not be allowed in C & D (construction and demolition) landfills, according to Bill Hinkley of Florida DEP.

In Hinkley's presentation on regulatory issues, he described how the state of Florida is currently evaluating whether CCA qualifies as C & D material, since construction and demolition material is defined as "non-polluting" and "non-leaching". According to Mr. Hinkley, "CCA wood, scrap and sawdust does not meet this legal definition." If CCA is re-classified, this could force C & D landfill owners to line their landfills or go out of business altogether, which would cause disposal fees to soar and increase illegal dumping in natural areas.

One thing was certain from today's meeting: the ongoing controversy over CCA, its toxicity and its disposal problems will be with us for a very, very long time.

By: Joseph Prager
Gainesville, Florida