US EPA

In January 2015, EPA released the draft literature searches and associated search strategies, evidence tables, and exposure response arrays for DBP to obtain input from stakeholders and the public prior to developing the draft IRIS assessment. Specifically, EPA was interested in comments on the following:

• Draft literature search strategies
• The approach for identifying studies
• The screening process for selecting pertinent studies
• The resulting list of pertinent studies
• Preliminary evidence tables
  • The process for selecting studies to include in evidence tables
  • The quality of the studies in the evidence tables

The literature search strategy, which describes the processes for identifying scientific literature, contains the studies that EPA considered and selected to include in the evidence tables. The preliminary evidence tables and exposure-response arrays present the key study data in a standardized format. The evidence tables summarize the available critical scientific literature. The exposure-response figures provide a graphical representation of the responses at different levels of exposure for each study in the evidence table.

Dibutyl phthalate is used as a plasticizer for nitrocellulose, polyvinyl acetate, and polyvinyl chloride; a lubricant for aerosol valves; an antifoaming agent; a skin emollient; and a plasticizer in nail polish, fingernail elongators, and hair spray. Dibutyl phthalate is: 1) classified as a Hazardous Air Pollutant under the 1990 Clean Air Act amendments; 2) included on the Office of Prevention, Pesticides and Toxic Substances 1990 high production volume chemical list; 3) listed as a Toxic Release Inventory chemical; and 4) found at hazardous waste and Superfund sites. The assessment will present reference values for the noncancer effects of dibutyl phthalate (RfD and RfC), where supported by available data, and a cancer assessment. The Toxicological Review will be subject to an internal and external peer review.

The U.S. EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of dibutyl phthalate that will appear on the Integrated Risk Information System (IRIS) database. Peer review is meant to ensure that science is used credibly and appropriately in derivation of the dose-response assessments and toxicological characterization.

U.S. EPA. IRIS Toxicological Review of Dibutyl Phthalate (Dbp) (Preliminary Assessment Materials). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-13/302, 2015.