For decades pressure treated lumber was treated with chromated copper arsenate (CCA) to prevent rot, fungus, and insect attacking the wood. The chemical treatment worked so well in preventing the wood from decay that it was quickly used in a variety of projects such as decks, fences, play structures, picnic tables, docks, and framing garden beds. On February 12, 2002 the EPA announced a voluntary decision by the industry to discontinue the consumer use of CCA treated lumber.
Pressure treated lumber is dipped into a bath of CCA and subjected to high pressure. This would force the chemical solution into the lumber. However, this process does not lock the chemical into the lumber. Over time some of the arsenic leaches out of the wood into the surrounding environment. In a typical application of pressure treated lumber in a deck, the posts that are buried in soil begin to release the arsenic into the soil. Arsenic would be released from the lumber when exposed to rain. The amount of arsenic leaching out of the wood is enough to contaminate the surfaces around and under the structure.
Few people, especially the home wood worker did not fully understand nor take into account the potential hazards of chemical treatment. The most toxic chemical in the treatment formulation is arsenic. Arsenic a known human carcinogen that is toxic to the skin and internal organs. Typically it takes years of exposure for the effects to manifest themselves.
When handling and working with pressure treated lumber there are several precautions to take to reduce your exposure to the harmful chemicals.
- Saw, sand, and machine CCA treated wood outdoors. Wear a dust mask, goggles, and gloves.
- Clean up all sawdust, scraps, and other construction debris thoroughly and dispose of it in the trash (municipal solid waste). Do not compost or mulch sawdust or remnants from CCA treated wood.
- Do not burn CCA treated wood because toxic chemicals may be released as part of the smoke and ashes.
- After working with the wood, wash all exposed areas of your body, especially the hands, thoroughly with soap and water before eating, drinking, or using the bathroom.
- Wash your work clothes separately from other household clothing before wearing them again.
Today pressure treated lumber is treated with either alkaline copper quaternary (ACQ) or copper boron azole (CBA). At your local home improvement store, check the label on the pressure treated lumber to see which method was used to treat it. Follow the manufacture’s guide lines on handling the material to reduce your exposure to harmful chemicals.
December 5th, 2006 at 7:46 am
Toni… thanks for the heads up. I never knew about the hazards of pressure treated lumber. Thanks again. Later…
December 5th, 2006 at 8:06 am
When I bought my house the previous home owner had built a patio cover and deck out of pressure treated lumber. It is nice and provides nice shade for the south facing windows in the summer.
However, the problem is the deck’s wood was aging and splitting open. My kids love to go outside and play. This summer we removed the deck boards and replaced it with pre-cast concrete pavers 16″ by 8″. It was a long weekend project, but well worth it.
A pleasant side effect is that we killed off a mosquito breading ground. The deck was raised up about 6” over the ground elevation. When it rained water would collect underneath the deck and sit for days! Nice gooey muck that provided a great mosquito breading ground!