Environmental and health issues with coal tar-based pavement sealers

Driveway sealers containing coal tar have been used for decades to protect asphalt driveways and keep them looking “new” or uniformly black. Coal tar-based sealcoat products contain high levels of polycyclic aromatic hydrocarbons (PAHs) which can be inhaled or ingested from dust or small particles. PAHs have been identified as “reasonably anticipated human carcinogens”, meaning they could cause cancer in humans and make pets sick.

Research also shows that coal tar-based sealers are a major contributor to increasing concentrations of PAHs in urban lakes. These lakes are used for drinking water and irrigation for fields that produce food for people and livestock. In addition, USGS studies show that aquatic organisms exposed to high levels of PAHs have stunted growth, difficulty swimming or righting themselves, and liver problems.

Due to these environmental impact and human health concerns, many governments have banned the use of coal tar sealant and many major home improvement stores no longer sell sealcoat products with coal tar. Alternative asphalt sealants offer a less toxic choice.

Asphalt-based sealers: a healthier and more environmentally sound alternative

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.

Do-it-yourself jobs:

• Read the label of the pavement sealing product carefully. Product labels containing the words “coal tar,” “refined coal tar,” “coal tar pitch volatiles,” “RT-12,” “tar” or similar terms mean the sealer contains coal tar.
• If the label references chemical abstract service (CAS) numbers 65996-93-2, 65996-89-6, or 8007-45-2 the sealer contains coal tar.