Farzad –
It is true that Coal Tar has been banned in a few places. There was a lot of hype about it a little while back due to a study that was conducted by the city of Austin Texas. Turns out their study was very flawed, but Coal Tar has still recieved some bad press from the media becuase of it. There actually is no proof that Coal Tar sealers cause cancer any more than Asphalt Emulsion. Check out this website to learn more about it. It’s a great resource. http://www.truthaboutcoaltar.com
I would love to hear from others on what they’ve heard.