Polycyclic aromatic hydrocarbon (PAH) mixtures

Overview

The document represents a brief, quantitatively oriented scientific summary of health effects data. It was developed by the Environmental Criteria and Assessment Office for the Office of Emergency and Remedial Response to provide interim guidance for the quantitative risk assessment of polycyclic aromatic hydrocarbons (PAH). For a more complete discussion of potential hazards from PAH exposure, the reader is referred to the 1992 Drinking Water Criteria Document for Polycyclic Aromatic Hydrocarbons (PAH). A literature search was not done in support of this short guidance document.

Background

Polycyclic Aromatic Hydrocarbons (PAHs) are products of incomplete combustion of organic materials; sources are, thus, widespread,including cigarette smoke, municipal waste incineration, wood stove emissions, coal conversion, energy production form fossil fuels, and automobile and diesel exhaust. As PAHs are common environmental contaminants, it is important that EPA have a scientifically justified, consistent approach to the evaluation of human health risk from exposure to these compounds.

For the majority of PAHs classified as B2, probable human carcinogens, data are insufficient for calculation of an inhalation or drinking water unit risk. Benzo[a]pyrene (BAP) is the most completely studied of the PAHS, and data, while problematic, are sufficient for calculation of quantitative estimates of carcinogenic potency. Toxicity Equivalency Factors (TEF) have been used by U.S. EPA on an interim basis for risk assessment of chlorinated dibenzodioxins and dibenzofurans. Data for PAHs do not meet all criteria for use of TEF. This document presents a somewhat different approach to quantitative estimation for PAHs using weighted potential potencies. These estimates are recommended only for evaluation of risk from oral exposure and are proposed only for the assessment of potential carcinogenicity of PAHS.

This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

• PROVISIONAL GUIDANCE FOR QUANTITATIVE RISK ASSESSMENT OF POLYCYCLIC AROMATIC HYDROCARBONS (1993) (PDF)  (28  pp, 1.0 MB, about PDF)

If you have a disability and the format of any material on our web pages interferes with your ability to access the information, please reach out to us using the Contact Us about IRIS form for assistance. To enable us to respond in a manner most helpful to you, please indicate the nature of the accessibility problem, the web address of the requested material, your preferred format in which you want to receive the material (electronic format (ASCII, etc.), standard print, large print, etc.), and your contact information.

Document Related Link(s)

• Development of a Relative Potency Factor (Rpf) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (External Review Draft, Suspended)
• Drinking Water Criteria Document for Polycyclic Aromatic Hydrocarbons (PAH) (Final Draft, 1985)