US EPA

The Health and Environmental Effects Profile for Phthalic Acids (o-, m-, p-) was prepared to support listings of hazardous constituents of a wide range of waste streams. Quantitative estimates have been presented provided sufficient data are available. p-Phthalic acid has been determined to be a systemic toxicant. A Reference Dose (RfD), defined as an estimate (with uncertainty spanning perhaps an order of magnitude) of the daily exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious effect during a lifetime, for p-phthalic acid is 1.4 mg/kg/day for oral exposure. Existing data are insufficient to determine a Reference Dose (RfD) or a carcinogenic potency factor for o- and m-phthalic acid. The Reportable Quantity (RQ) value of 1, 10, 100, 1000 or 5000 pounds is used to determine the quantity of a hazardous substance for which notification is required in the event of a release (as specified by CERCLA) based on chronic toxicity. The RQ value for p-phthalic acid is 1000. Existing data are insufficient to determine an RQ value for o- and m-phthalic acid.

U.S. EPA. Health And Environmental Effects Profile for Phthalic Acids (O-, M-, P-). U.S. Environmental Protection Agency, Washington, D.C., EPA/600/X-86/292 (NTIS PB89138838), 1986.