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Reprint of an article appearing in Cleaner Times, November 2005
A few years ago headlines appeared in USA Today and other publications that announced to the general population that there was danger lurking in their backyard. Pressure-treated lumber, used all over the country in homes and for decks, fences, childrens’ play sets, and other outdoor structures was the latest target of an EPA investigation.
The article came out at the time of the annual PWNA convention in Orlando, Fl., and all of the contractors involved in residential pressure washing could not talk about anything but this topic for the three days we were together. Would PT lumber be banned? Would we be prevented from working? Are we in any danger? Had we been exposed to something that would haunt us later? The questions were endless.
The controversy was centered on the chemical used to treat the lumber, called CCA (Chromated Copper Arsenate). The EPA suspected that the poisonous arsenate could leach from the wood when it was exposed to water, such as during a rain or during the power-wash process. The arsenate compounds could be picked up innocently by simply touching the wood after a rain. There was also concern that this leaching would contaminate the soil near the wood. Playgrounds were immediately considered to be the most dangerous use of CCA lumber. The belief at the time was that this represented a significant health risk and warranted a direct government study to determine the extent of the problem.
Why was CCA lumber so scary? Consider these statistics: A lethal dose of arsenic to humans has been estimated to be about 42 mg. within a day for a 150 lb. adult. For a 20 pound child, this works out to 6 mg. To put this in perspective, a 12 foot long 2x6 contains about 27,000 mg. of arsenic, enough to kill hundreds of adults. The poison is potentially ingested by transfer from hands to mouth. It could also potentially be ingested by breathing contaminated dust on a playground.
The industry countered that there were no clearly identifiable cases of arsenic poisoning that could be attributed directly to CCA lumber.
The lumber industry entered into a voluntary agreement at the time with the EPA to phase out CCA lumber and replace it with lumber treated with one of several readily available substitutes. The agreement reached called for the phase-out to take place over the following two years. It was reported at the time that this action would probably eliminate the EPA’s desire to conduct a study.
The most interesting part of the announcement was the EPA’s recommendation of how to deal with the existing lumber in use all over the country. It was estimated that 80% - 90% of all decks in the country were built with PT lumber. The EPA suggested to the general public that treating the wood by sealing it would prevent the leaching of the arsenate. Big collective sigh of relief from all of the power wash folks…
The EPA issued a press release that stated in part that EPA did advise homeowners to remove existing decks and other structures made with wood. However, regularly coating the lumber with sealant is suggested as a way to reduce any arsenic risks.
The actual EPA recommendations went on to say that parents should make sure that children who play on or near decks or play sets should always wash their hands thoroughly after contact with treated wood, especially prior to eating and drinking, and ensure that food does not come into direct contact with any treated wood.
The agency also said that workers should take some precautions when handling pressure-treated wood. They should wear gloves when handling wood, wear goggles and dust masks when sawing and sanding, always wash hands before eating, and never burn CCA treated wood. In spite of the agreement with lumber producers, the EPA, in a joint effort with the Consumer Product Safety Commission, went on to do a 2-year study. Beginning in 2003, these agencies investigated the effect of sealing wood as a preventative for the leaching problem. Fast forward to 2005, and that study is just finishing up. The final results are expected to be released several months from now. Preliminary results are just becoming available, and the power washing industry is again holding its breath.
The agencies studied both new wood and aged wood. The EPA concentrated on evaluating sealers on old wood while the CPSC concentrated on studying the effects of sealers on new wood. Their primary concern was whether or not sealing the wood with many of the popular brands of sealers would effectively reduce the occurrence of leaching of the arsenate. Children were considered to be the most vulnerable to this problem, because of their body size and their proximity to play sets constructed of pressure-treated lumber.
The preliminary study results can be seen on the EPA’s own website. The methodology used to conduct the study is outlined on the CPSC web site. In effect, each of the agencies discovered that all of the sealants tested significantly reduced the occurrence of leaching for the first twelve months. (The preliminary results are based on the first twelve months of results only. The 24-month results will be released by the end of this year or early next year.) It is expected at this time that the leaching problem will be significantly higher during the second year for many of the sealers tested.
Several different types of sealers were tested. The products tested included: 1. "Film formers" such as paints that form a film on the wood surface, 2. Penetrating stains and sealants which absorb into the wood, and, 3. Those designed to encapsulate CCA (e.g., plastic-type products).
(It must be noted that a number of consumer groups have already questioned the validity of the studies and the techniques used to gather results. The primary complaint about the studies is that they concentrate on the cause and effect of arsenate exposure without looking at chromium exposure and its impact.)
The EPA’s web site reports that “While the top two performers were film-forming coatings (e.g., paints), the other more typical deck treatment products - specifically sealants and stains - performed similarly in reducing the amount of dislodgeable arsenic at the surface of the wood.”
The EPA went on to state that film-formers like paint, even though they performed well, were not the best choice because of the potential for chipping and flaking. They also suggested that removing film formers by sanding or power washing presented additional exposure hazards. The EPA went on to comment that the encapsulating vinyl products were not the best choice since they also chipped over time. Re-coating with these products might require removing the old product before the new coat could be applied, which made the problem worse.
Penetrating sealers were the overall preferred solution to the problem, according to the EPA preliminary results.
A search of the CPSC’s study indicates that the agency found very similar results to the EPA study.
The voluntary phase-out of CCA lumber means that pressure-treated boards made since January 1, 2004, do not contain CCA. The most common replacement is called ACQ (Alkaline Copper Quaternary) lumber, which contains no arsenate or chromium derivatives. Since so many power washing contractors do residential work involving older structures, exposure to CCA lumber day after day is very likely. Understanding the issues and using appropriate caution is always a good idea.
At this time, the agencies are sticking to the original prescription for preventing exposure to the arsenate poison found in most pressure-treated lumber made prior to January 1, 2004. Both studies reach the same preliminary conclusion: Regular treatment of the wood with a quality wood sealer is still the best prevention technique known for consumers and property owners. Until the studies are ready to be released, the same common sense suggestions for handling and working with PT lumber remain the best advice.
So where does that leave professional power wash contractors who make their living cleaning this wood? Common sense tells you that awareness is your best defense. Cleaning methods and the precautions used should address the cumulative effect of this poison. Be careful to wash your hands often during the day. You should certainly avoid touching your face or food without washing your hands first. Gloves are necessary when you handle the wood, and you should be very careful not to inhale sawdust during the cutting or sanding of old PT lumber. Washing your clothes after each use is probably a smart idea as well. You should even avoid tracking trace amounts of arsenate onto the kitchen floor when you go home at night, particularly if you have small children that might crawl on those surfaces. Their tolerance is very low.
With all of these scary precautions, is it time to walk away from this business? Most of us take more of a risk just driving to the job than we do from CCA lumber. While we can’t protect ourselves from that other driver, we can certainly protect ourselves from excessive CCA exposure. We are in the driver’s seat.
Once again this year the EPA will make several public statements to all citizens about the importance of sealing decks and play sets. If history repeats itself, the news services will be quick to jump on board with a few sensational headlines, too. With the government encouraging your customers to do this service annually, you are in a great position to gain new customers and make your existing ones breathe easier. I suggest that each of you add information on the importance of sealing wood for safety reasons to your customer presentation.
Ya’ll can exhale now.
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