Coal Tar

Coal tar, also commonly known as poly tar, airport grade, coal tar emulsion, refined tar based sealer, and coal tar pitch have been the solution for asphalt maintenance and protection for decades. However like many things over the years we find ourselves looking at new and improved methods of getting the same results making things better, stronger, more cost effective, and in the last decade more environmentally friendly.

Being the solution for decades the first question asked is “why do we need to replace it?” To answer this question we need to understand what coal tar sealer really is.

Coal tar is a by product of coking, liquefaction or gasification of coal. Coal tar pitch is the product that remains after the distillation of coal tar. It is then separated and the most viscous material (RT-12) is used to make coal tar based sealant. It has extremely high concentrations of PAH’s (polycyclic aromatic hydrocarbons) and is a classified as a known human carcinogen.   Now of course PAH’s are found in lots of things we use every day but to give you an idea of how it compares. Coal tar sealer contains 35,000 to 200,000 mg/kg (ppm or parts per million). That’s almost 1,000 times more PAH’s then oil based asphalt sealers.

Research & Studies

The Canadian government says “choose driveway sealants that don’t contain coal tar.”

Coal Tar and Their Distillates

Coal Tar Sealers Cause Genetic Mutations

Coal-Tar Sealant Implications for Health and Environment

Belleville action plan for coal-tar pollution

United States Geological Survey Studies negative effects of coal tar


We encourage everyone to learn about products.  There are hundreds of cities, communities, universities, and property managers that have taken the next step by banning toxic products from being put down on their asphalt.

Guardian Driveway Sealing does not use coal tar or coal tar based products, we only use environmentally friendly products for the protection and longevity of your asphalt.