The City of Austin amended its Code to ban the use and sale of pavement sealants with more than .1% (1000 ppm) PAH by weight within the City’s planning jurisdiction (full purpose city limits and ETJ). The one exception is that the sealant may be sold if the intended application area is outside the City’s ETJ. The Austin ban was effective January 1, 2006 and was amended October 17, 2019 to expand the prohibition from coal tar to high Polycyclic Aromatic Hydrocarbons (PAH) sealants.
PAH’s are a group of chemicals formed during the incomplete burning of coal, gasoline, wood, garbage or other organic substances such as tobacco, charcoal broiled meat, and incense. As a pollutant, they are of concern because some compounds have been identified as cancer-causing. For example, one PAH compound, benzo[a]pyrene, is notable for being one of the first chemical carcinogens discovered; one of many found in cigarette smoke. PAHs are lipophilic (mix more easily with oil than water). The larger compounds are less water-soluble and less volatile (less prone to evaporate). Therefore, PAHs in the environment are found primarily in soil, sediment and oil substances, as opposed to water or air. However, they can be found in particulate matter suspended in air.
High PAH sealants may contain coal tar, coal tar pitch volatiles, RT-12, refined tar, steam-cracked petroleum residues, heavy pyrolysis oil, steam-cracked asphalt, pyrolysis fuel oil, heavy fuel oil, ethylene tar, ethylene cracker residue, or a variation of those substances assigned the chemical abstracts service (CAS) numbers 65996-92-1, 65996-93-2, 65996-89-6, 8007-45-2, 64742-90-1, or 69013-21-4; and is for use on an asphalt or concrete surface, including a driveway, playground, or parking area.
PAHs are a high-profile pollutant of growing concern nationwide, due to increasing concentrations in waterways
The ban provides an unprecedented opportunity to eliminate a significant pollutant threat to our local water resources
The combination of chemical tracing, laboratory toxicity, and field-verified degradation provides ample evidence to support regulatory action to remove the use of high PAH sealants within the City’s jurisdiction.