Is Sealcoating Toxic?
Asphalt is the most commonly used paving material in modern civil engineering. From parking lots to driveways to highways, asphalt is preferred due to its durability, aesthetics, and longevity.
What’s the secret to asphalt’s durability? Aside from its inherent properties, sealcoating further strengthens the asphalt. The sealcoat material protects the surface from elements such as harsh climates, corrosive chemicals, and the effect of wear and tear.
Asphalt sealing is vital to make the pavement last longer. While sealcoating is a relatively common preventative maintenance for asphalt, you may have probably heard that asphalt sealer is toxic. A common question of many homeowners: Is sealcoating toxic?
Which Type of Sealer is Toxic?
According to the US Geological Survey, coal-tar-based sealant products contain a high concentration of Polycyclic Aromatic Hydrocarbons (PAHs) which are considered toxic. PAHs are naturally occurring compounds in coal, gasoline, and crude oil. Although exposure to low levels of PAHs has no known human health effects, some specific mixtures of PAHs are associated with a higher risk for cancer, birth defects, mutations, or animal death.
Using coal-tar-based sealant increases PAHs concentration in nearby areas by up to 25 times. Exposure to sunlight further intensifies the potency of some PAHs.
Coal-tar-based sealants are the major source of PAHs in the environment. Sealed surface emits PAHs into the air above, usually, as dust particles, that can be flown into homes and washed into surrounding bodies of water. Dried sealcoat particles that contain high levels of chemicals can be transported by car tires, wind, and rain to the surrounding environment. We can also bring it inside our homes through our footwear. Soils, dust, runoff, and sediment near pavements sealed with refined-tar-based sealcoat have higher concentrations of PAHs compared to unsealed pavements.
Some experts warn that the risk of cancer can increase by 38 percent for people living around coal-tar sealed asphalt. The risk among children is higher as they spend more time outdoors.
PAHs are toxic not only to humans but also to the environment. Even long after sealcoating is installed and dries up, PAHs continue to be washed into waterways. As the sealcoat surface disintegrates, the toxic chemical compound is released into the surroundings. High concentrations of this compound, especially in runoffs and waterways, can lead to death among aquatic species.
This toxic compound is an environmental concern that many advocates push for regulation and monitoring. Although there are some claims that the impact of PAHs in the environment is minimal, experts believe that the long-term effects of such chemicals can harm the ecosystem. Whenever possible, eco-friendly and non-toxic sealants should be used for your paving.
Safer Alternatives
An asphalt-based sealcoat is a safe substitute. Although these products still contain PAHs, their concentration is 1000 times lower than the coal-tar-based sealants. In fact, several home improvement chains have stopped selling sealants with toxic and unsafe levels of PAHs. If you are planning to have your asphalt driveway sealed, be sure to use a safe sealcoating product. Likewise, if you’re hiring a paving contractor, ask about the product they intend to use.
Experienced sealcoat installers from ABС Paving, a sealcoating contractor from Florida, emphasized that caution should be taken when applying refined tar-based sealants. To minimize exposure, it is best to hire paving contractors. These professional pavers are trained and experienced with the proper handling and installation of different types of sealers. Paving contractors use appropriate clothing like work gloves, full-length pants, long sleeves, hats, and face shields.
Contact to refined tar sealers can result in sunburn effects, especially when exposed to sunlight. Protective creams can be used to further minimize contact with the sealer and exposure to sun rays that can increase skin irritation. With proper handling and safety gear, applying an asphalt sealcoat should be safe.
If you are yet to install pavement, you can consider other paving materials aside from asphalt that don’t require sealing like permeable asphalt, permeable pavers, or concrete. Permeable paving materials allow water to be absorbed and further prevent PAHs from runoff. These paving materials offer similar durability and longevity except that they won’t need frequent sealcoating. They are safe options not just for your family but also for the environment.
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Is Sealcoating Toxic?