PavementCouncil.org asked Dr. Brian Magee, a toxicologist with expertise in PAHs and in risk assessment, to review a paper claiming to show that people living near paved surfaces sealed with RTS have an elevated risk of cancer. The conclusions of Dr. Magee’s peer review report include the following statement. The long history of use of coal tar as a therapeutic agent demonstrates that coal tar exposures do not increase people’s risks of cancer. There is no evidence that low level or intermittent exposure to coal tar or coal tar pitch has caused cancer in humans. There is little evidence that high level repeated exposures have caused cancer in humans. There are some studies about high temperature industrial processes such as aluminum smelting or coke oven gases that show some adverse effects but these studies have no relevance to coal tar sealants. Read the entire report here.
Refined Tar-Based Sealers
The peer review report mentioned above also concluded that: “Although PAHs are present in coal-tar-based sealants, there is no evidence that coal-tar-based sealants affect people’s health. Furthermore, there is no evidence that people who intentionally put pure coal tar on their skin cause health risks. In fact, there is good evidence that it does not.” Read the whole peer review report here.
Ready-to-use pavement sealers (both refined coal tar and asphalt based) have never been cited for a claim of bad health due to the use of it’s sealers. Sealers are manufactured with high quality ingredients in strict accordance with all federal, state and local requirements.
Air sampling studies showed refined coal tar based sealers pose no inhalation risk to applicators, manufacturers or the general public (see Koppers’ study about using RTS safely here).
The USGS team that, based on flawed “science” has been conducting a taxpayer-funded advocacy campaign targeting RTS published a “risk assessment” in 2013 purporting that people who live near pavements sealed with refined tar have elevated cancer risks. To reach that conclusion, the “risk assessors” exaggerated exposures, used soil samples collected immediately next to paved surfaces that contained materials not associated with RTS and, in short, violated as many of the “rules” of risk assessment as they needed to achieve a calculated risk above levels of concern. You can read the details here.
Coal Tar Pharmaceuticals
Coal tar has been used to treat people with skin conditions such as dandruff, sebborrheic dermatitis and psoriasis for over 150 years, and today is recognized by the US Food & Drug Administration (FDA)as “generally recognized as safe and effective” (GRASE). The Code of Federal Regulations entry for medicinal coal tar is 21CFR358.
In response to a petition from a private citizen, FDA reviewed the use of coal tar-containing creams, lotions and shampoos to determine whether those products should continue to be available as Over-the-Counter (OTC; which means available without a prescription) medicines. The conclusion reached in FDA’s formal review, completed in 2001 and posted here, was as follows “Our review of information in your petition, comments submitted to the docket, and reports in FDA’s Adverse Events Reporting System did not disclose new evidence that the risk of cancer is greater in consumers who regularly use OTC drug products containing coal tar than in consumers who do not.“.