Risk Evaluation for Di-isononyl phthalate (DINP) (1,2-Benzene- dicarboxylic acid, 1,2- diisononyl ester)

In August 2024, EPA released the draft risk evaluation under the Toxic Substances Control Act (TSCA) for di-isononyl phthalate (DINP) (1,2-benzenedicarboxylic acid, 1,2-isononyl ester) for public comment.

In May 2024, EPA released the draft physical chemical, fate, and hazard assessments for DINP for public comment and peer review. EPA granted the manufacturer request for risk evaluation for DINP in December 2019.

Learn more about manufacturer-requested risk evaluations.

Find other information about other chemicals undergoing risk evaluations under TSCA.

On this page:

Risk Evaluation Findings
Hazard Assessment for DINP
Background on DINP
Uses of DINP
Recent Activities and Opportunities for Public Comment
Supporting Documents

Risk Evaluation Findings

EPA preliminarily determined that two industrial uses and one consumer use significantly contribute to the unreasonable risk of DINP.

EPA assessed exposure for 45 TSCA conditions of use of DINP. The two worker uses that EPA identified as preliminarily contributing to unreasonable risk involved unprotected workers using spray adhesives and sealants or paints and coatings that contain DINP with high-pressure sprayers. This is because doing so could create high concentrations of DINP in mist that an unprotected worker could inhale.

EPA identified one consumer use as preliminarily contributing to unreasonable risk to infants, toddlers, and preschool children under the age of 5 who may be exposed to dust containing DINP that migrated from floor coverings and building and construction materials, such as vinyl flooring, in-place wallpaper, and carpet backing.

Hazard Assessment for DINP

EPA requested external peer review on the DINP hazard assessment in advance of releasing the full draft risk evaluation for public comment in August 2024.

EPA has preliminarily determined that DINP can cause developmental toxicity and liver damage. DINP could also cause cancer at higher thresholds (i.e., at levels of exposure higher than those that cause non-cancer liver and developmental toxicity) and has the potential to cause "phthalate syndrome."

Background on DINP

DINP is a common chemical name for the category of chemicals that includes the following substances: 1,2-benzenedicarboxylic acid, 1,2-isononyl ester and 1,2-benzenedicarboxylic acid, and di-C9-11-branched alkyl esters, C9-rich. The primary use for DINP is as a plasticizer in plastic and rubber products. Information from the 2016 Chemical Data Reporting (CDR) for DINP indicates the reported production volume is between 200 and 500 million lbs/year (domestic manufacture including import).

Uses of DINP

In the final scope of the DINP risk evaluation, EPA identified conditions of use under TSCA associated with the manufacturing (including importing); processing; distribution in commerce; industrial, commercial and consumer uses; and disposal of DINP, including:

As a plasticizer in polyvinyl chloride (PVC);
In building and construction materials;
In automotive and fuel products; and
In other commercial and consumer products, including adhesives and sealants, paints and coatings, electrical and electronic products, and other plastic and rubber products.

The above listed conditions of use are ways that a person or the environment could be potentially exposed to DINP. However, when conducting a risk evaluation, EPA also considers the hazards (i.e., health effects or environmental impacts) that could occur from coming in contact with a chemical.

There are other uses of DINP that do not fall under TSCA, such as personal care products, cosmetics, and food contact materials.

Recent Activities and Opportunities for Public Comment

In May 2024, EPA released the draft physical chemical, fate, and hazard assessments for DINP for public comment and peer review. EPA accepted public comments on the draft documents for 60 days following publication in the Federal Register via docket EPA-HQ-OPPT-2024-0073 at www.regulations.gov.

EPA held a virtual peer review public meeting of the Science Advisory Committee on Chemicals (SACC) to discuss the draft risk evaluation documents from July 30 to August 1, 2024. EPA also held a virtual preparatory public meeting on July 23, 2024, for the SACC and the public to consider and ask questions regarding the scope and clarity of the draft charge questions and areas of review. EPA did not develop charge questions for all aspects of the draft risk evaluation materials for DINP; instead, the agency asked the SACC to review specific scientific areas that need peer review. View the SACC website for more information on these meetings.

In August 2021, EPA published the final scope document outlining the hazards, exposures, conditions of use, and the potentially exposed or susceptible subpopulations the agency expects to consider in its risk evaluation. The agency released the draft scope in November 2020 and took public comments on the draft document.

As EPA continues to move through the TSCA risk evaluation process, there will be additional opportunities for public comment, including a public comment period on the draft risk evaluation. In addition to multiple public comment periods, EPA will continue to engage with stakeholders as it develops the risk evaluation, and stakeholders should reach out to EPA via the staff contact to engage with the agency.