"Washington has become the first state to ban pavement sealants that contain coal tar. The state made the move in response to recent studies that show runoff from macadam treated with these products can pollute lakes and streams.
On May 5, Gov. Christine Gregoire (D) signed into law legislation that will ban sales of coal tar-based pavement sealants in Washington starting on Jan. 1, 2012. The new statute also bars application of coal tar sealants in the state as of July 1, 2012.
Coal tar sealants contain polycyclic aromatic hydrocarbons (PAHs), a group of chemicals that are ubiquitous in the environment, especially in urban areas. PAHs can come from vehicle exhaust, particles worn off tires, and atmospheric deposition. PAHs are also found in crude oil, creosote, and roofing tar. Some, meanwhile, are used to manufacture pharmaceutical products, dyes, plastics, and pesticides."