Comprised of 22 percent pure arsenic, chromated copper arsenate sounds nasty and it is. Unfortunately, it is as common as it is toxic. Known as CCA in the building trades, chromated copper arsenate has been the most popular wood preservative and pesticide used to manufacture pressure treated lumber since the 1940’s. From picnic tables, to decks, to docks to playground equipment, you can find CCA treated lumber nearly everywhere you go.

CCA is applied under very high pressures to ensure deep penetration into the wood. The assumption over the years is that CCA was not a potential health risk because the pesticide was contained within and restrained by the wood product. There is now substantial evidence that that assumption was incorrect. Arsenic leaches to the surface and as such may be picked up by contact or washed off during rain events.

Although environmentalists have been warning about the potential health risks associated with CCA treated wood for years, the issue is just now beginning to receive the attention that it deserves. Obviously, arsenic is a poison that kills in sufficient doses (and it doesn’t take very much!) but the biggest health risks may come from the arsenic poisoning that can result from cumulative exposures at much lower levels. Digestive tract pain, nausea, vomiting, diarrhea, heart abnormalities, blood cell and blood vessel damage, liver and kidney damage, impaired nerve function and skin abnormalities commonly are associated with non or pre-fatal arsenic poisoning. In addition, arsenic is a known human carcinogen that can cause cancer effecting the liver, lung, kidney and bladder.

In particular, the risks posed by CCA products appear to be highest in the following instances:

1. People working with pressure treated wood, both at the time of its manufacture as well as its application. Of particular concern is the cutting or milling of the wood when particles may become airborne.

2. Surface to skin contact on play surfaces and/or tables. Although there is little empirical evidence to justify a concern about absorption of inorganic arsenic through the skin, there is a growing body of evidence to suggest that inorganic arsenic can be easily transferred from the skin to the mouth were it is readily absorbed into the body. Thus, children who play on equipment made with CCA products are particular susceptible. The same principle applies to food that is placed directly on a CCA wood surface. The food may pick up leeched arsenic and be transferred to the body when the food is consumed.

3. The area directly beneath play equipment or decks can become contaminated with arsenic when the arsenic that leaches from the wood is washed off by rain. Studies by The Connecticut Agricultural Experiment Station showed elevated levels of arsenic under each of the decks that they tested where levels in the soil ranged from 3-350 mg/kg with an 76 mg/kg average (Connecticut state limit = 10 mg/kg). The levels in the soil showed a tendency to increase with age.

4. The burning of CCA treated products can create serious health risks as the arsenic can become airborne and is easily ingested into the lungs. There have been documented cases of arsenic poisoning in cases where people have used pressure treated lumber as a fuel source for indoor wood stoves. This should be avoided at all costs.

Obviously, the potential health risks associated with CCA are worthy of evaluation. To what level we will be impacted by our use of CCA remains an unanswered question. Florida has already closed numerous public parks that had CCA based play equipment and the U.S. Consumer Product Safety Commission is considering a ban on the use of CCA treated wood in playground equipment.

In February 2002, the EPA announced a volunteer industry withdrawal of CCA products from the market by December 31, 2003. Products already in the distribution channel at that time will not be recalled and will continue to be sold. This action will certainly help control the further expansion of CCA usage but it does nothing to either confirm or contradict the existence of a problem nor does it provide or suggest any remedy in the event that health risks prove to be substantial.

At this point in time it would seem that prudence rather than panic is the appropriate course of action. Proper precautions can greatly reduce any potential hazards that may exist.

We would recommend that local governments with responsibility for community playgrounds that contain CCA based play structures implement an immediate and ongoing testing program to evaluate their structures. Those structures that have high CCA levels should be closed until remedial steps can be taken. Short term steps may include cleaning and sealing but municipal officials need to be aware that such steps have a limited effectiveness and are short term in nature. Replacement should be considered.

 

Links

Environmental Working Group – This organization is extremely active in the effort to ban CCA based products and their website is extremely robust. It contains a great deal of information on the CCA issue as well as on numerous other topics. Checkout their home page while you are there and make sure you take a look at their articles “All Hands on Deck” and “Poisoned Playgrounds”.

EPA announcement on a voluntary decision by industry to move consumer use of treated lumber products away from a variety of pressure-treated wood that contains arsenic by Dec. 31, 2003, in favor of new alternative wood preservatives.

Canadian Medical Association Journal – A discussion of the issue by our neighbors to the North.

CCAResearch provides some interesting information that is hard to find elsewhere. Check out their RCRA Presentation under General Information. Even though it takes a long time to load, even with high speed Internet access, it is worth the effort.

Consumer Protection Safety Commission Fact Sheet - This link will take you to the CCA fact sheet prepared by the CPSC. Much more detailed information is available by reviewing the links to the briefing documents located at the bottom of the page.

EPA Info – This link provides access to a number of EPA document regarding CCA products.

Sierra Club – The New Hampshire Chapter has done an admirable job of providing access to information on CCA issues. Check them out.

St. Petersburg Times – News stories on CCA issues from Florida.

Treated Wood Info Center – This site provides information on treated wood as well as information on lawyers dealing with the issue. The lawyer part makes us a bit nervous.