This Post is Prepared by Donnie Dann
Your driveway has cracks, it’s old looking and unquestionably requires work. Someone leaves a pamphlet in your mailbox or phones you and offers to seal your driveway to make it beautiful and successfully repair it. Further, the price is right, jut a few hundred dollars. It’s an offer you can’t refuse.
My advice? Refuse it! Here’s the United States Geological Survey’s (USGS) summary about the coal tar derived material typically used as a driveway sealer, but I commend the entire article to you here.
“Coal-tar-based sealcoat—a product marketed to protect and beautify asphalt pavement—is a potent source of toxic polycyclic aromatic hydrocarbons (PAHs) to air, soils, streams and lakes, and homes. Does its use present a risk to human health?” The is answer is a resounding YES!
Some of the brands of sealants contain as much as 35% coal tar, a known carcinogen according to the National Toxicology Program. It’s no surprise that the industry group, Pavement Coatings Technology Council strongly denies the carcinogenic properties found by the USGS and other researchers. A water quality scientist of the Minnesota Pollution Control Agency, has said “we have done rigorous, scientific surveys and analyses showing coal tar sealants are a major sources of PAHs in the environment”. Coal tar is banned in several places, including my home town, Highland Park, IL
An excellent analysis and comparison of industry claims with a side by side refutation is available here.
Far less toxic alternatives are available: This is from N. Y. State’s Department of Conservation:
“Asphalt based sealers are available which contain 1,000 times less PAH than coal tar sealers. Choose an asphalt-based sealer, whether you are hiring someone, or doing the job yourself. If you are hiring a professional to seal your driveway: Ask the contractor what type of sealers they use. The contractor should be able to tell you whether their product is coal tar or asphalt-based. If your contractor is unable to tell you what is in their sealer, or you would like to verify their answer, request the safety data sheet on their product. If the safety data references chemical abstract service (CAS) numbers 65996-93-2, 65996-89-6, or 8007-45-2, the sealer contains coal tar. If any of the material references the words “coal tar,” “refined coal tar,” “coal tar pitch volatiles,” “RT-12,” “tar” or similar terms the sealer contains coal tar.”
The irony of using coal tar sealants is that they don’t really work. Sure, for some weeks your driveway looks new, but it won’t be long before that completely black appearance is gone and it appears much as it did before the application, including un–healed cracks. In other words its value is cosmetic. Meanwhile the carcinogens run from your driveway to surrounding habitat, including your home.
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