Introduction to Comments on 

Benzo(a)Pyrene

IRIS Bimonthly Meeting 

December 12-13, 2013 

Anne P. LeHuray, Ph.D.

Pavement Coatings Technology Council

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Comment Sponsors

• American Coke and Coal Chemicals Institute

• American Fuels & Petrochemical 

Manufacturers 

• American Petroleum Institute

• Asphalt Institute

• Association of American Railroads

• Beazer East, Inc.

• Pavement Coatings Technology Council

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Thank You, EPA...

• For granting extension 

– We hope the result of the extra time is evident in the 

thorough review of primary literature

– Written comments are organized by EPA’s draft peer 

review charge questions

– The B(a)P & PAH mixture literature is vast. Even 90 

days was insufficient to address every draft charge 

question

• For this opportunity to review and discuss the 

draft assessment at this stage, before the 

document is ready for peer review

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Assessment of B(a)P is Unique

• People are not exposed to B(a)P per se, but to B(a)Pcontaining mixtures 

– Of which there are uncounted thousands

– Each B(a)P-containing mixture has a unique composition with 

more or less PAH compounds such as BaP per se

– B(a)P-containing mixtures contain a variety of heterocyclic PAH 

compounds and non-PAH compounds

• B(a)P per se is not used in commerce or emitted by itself 

into the environment from industrial processes

– Industrial and natural processes produce and use complex 

mixtures which contain PAHs and hundreds of related and 

unrelated compounds. 

• EPA has designated B(a)P per se as the index chemical for 

the PAHs

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Assessment of B(a)P is an Opportunity

• B(a)P per se is arguably the most studied 

substance in toxicology

– but no human exposure data

• B(a)P-containing mixtures are arguably the most 

studied materials in the environment

– and there are human exposure data including 

occupational, clinical and ambient data

• We urge EPA to take advantage of the 

opportunity presented to validate hazard & 

calculated risk estimates against real world data

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Summary of Estimated Daily BaP-TE 

Intakes*

* From report prepared by ARCADIS in 2013 for PavementCouncil.org

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Coal Tar Pharmaceuticals

• Coal tars of all varieties contain an elevated 

percentage of PAHs

• FDA lists coal tar as “generally recognized as 

safe and effective” (GRASE) for use as an 

active ingredient in medicine to treat certain 

skin disorders

• GRASE-listed materials are approved for use in 

Over-the-Counter drugs

• Clinical data available

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21CFR§358.710

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§ 358.710 Active ingredients for the control of dandruff, seborrheic

dermatitis, or psoriasis.

The active ingredient of the product consists of any of the following 

within the specified concentration established for each ingredient:

....

(a) Dandruff

(b) Seborrheic dermatitis

(c) Psoriasis

...

(1) Coal tar, 0.5 to 5 percent. When a coal tar solution, derivative, or 

fraction is used as the source of the coal tar, the labeling shall specify the 

identity and concentration of the coal tar source used and the 

concentration of the coal tar present in the final product.
Another way to look at PAHs

Ingredients for Life

• This artist's conception [next slide, from NASA’s “image of the day” 

gallery] symbolically represents complex organic molecules, known as 

polycyclic aromatic hydrocarbons, seen in the early universe. These large 

molecules, comprised of carbon and hydrogen, are among the building 

blocks of life. NASA's Spitzer Space Telescope is the first telescope to see 

polycyclic aromatic hydrocarbons so early--10 billion years further back in 

time than seen previously. Spitzer detected these molecules in galaxies 

when our universe was one-fourth of its current age of about 14 billion 

years. These complex molecules are very common on Earth and form 

[when] carbon-based materials are not burned completely. They can be 

found in sooty exhaust from cars and airplanes, and in charcoal broiled 

hamburgers and burnt toast. Polycyclic aromatic hydrocarbons are 

pervasive in galaxies like our own Milky Way, and play a significant role 

in star and planet formation. 

Image Credit: NASA/JPL-Caltech/T. Pyle (SSC)

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