Power washing of pressure treated decks and lumber in Maryland has become a topic of discussion since the Environmental Protection Agency made some changes in the pressure treating process of lumber. Here are some quotes from their website. "On February 12, 2002, EPA announced a voluntary decision by industry to move consumer use of treated lumber products away from a variety of pressure-treated wood that contains arsenic."
To read all the information on this announcement see the EPA website.
One of their recommendations to help prevent exposure to CCA is to apply a coating product to pressure-treated wood on a regular basis. They state that some studies suggest that this can reduce the amount of CCA that leaches from treated wood.
What types of coatings are most effective?
We do not recommend surface film forming stain agents or painting of decks. Most of these paint and stain agents have a tendency to wear or peel off and these particles may have CCA on them. For the best protection of your wood surface from the elements and CCA, see our staining page.