EPA Issues Draft Risk Evaluation for Diisononyl phthalate (DINP) for Public Comment
Released August 30, 2024
Today, the U.S. Environmental Protection Agency (EPA) released its draft risk evaluation for diisononyl phthalate (DINP) under the Toxic Substances Control Act (TSCA) for public comment. In the draft risk evaluation, EPA preliminarily determined that two industrial uses and one consumer use significantly contribute to the unreasonable risk of DINP out of the 45 uses evaluated. EPA preliminarily determined that DINP has the potential to cause developmental toxicity and harm the liver, and that it could cause cancer at higher levels of exposure. DINP has the potential to cause effects on the developing male reproductive system commonly known as phthalate syndrome. EPA also preliminarily determined that DINP does not pose unreasonable risk of injury to the general population or pose unreasonable risk to the environment.
DINP is used primarily as a plasticizer to manufacture flexible polyvinyl chloride (PVC). It is also used to make building and construction materials; automotive and fuel products; and other commercial and consumer products including adhesives and sealants, paints and coatings, electrical and electronic products. There are other uses of DINP that are generally excluded from TSCA, such as personal care products, cosmetics, and food contact materials, and EPA did not evaluate risk associated with these uses.
Workers may be exposed to DINP when making products containing DINP or otherwise using DINP in the workplace. When it is manufactured or used to make products, DINP can be released into the water where most of it will end up in the sediment at the bottom of lakes and rivers. If it is released into the air, it will attach to dust particles and then be deposited onto land or into water. Indoors, DINP has the potential over time to come out of products and adhere to dust particles. If it does, people could inhale or ingest dust that contains DINP.
EPA preliminarily determined that one consumer use of DINP contributes significantly to unreasonable risk: the use of DINP in floor coverings and construction and building materials covering large surface areas, such as vinyl flooring, in-place wallpaper and carpet backing. This use significantly contributes to the unreasonable risk of DINP to infants, toddlers and preschool children under the age of five to dust containing DINP that migrated from these materials via the air, direct contact, or both.
The two worker uses that EPA preliminarily determined contribute significantly to the unreasonable risk to workers involved unprotected workers using spray adhesives and sealants or paints and coatings that contain DINP with high-pressure sprayers. Using these sprayers could create high concentrations of DINP in mist that an unprotected worker could inhale. EPA was not able to identify products containing DINP that are currently used in high-pressure spray applications and expects that public comments on this draft will help address this uncertainty.
EPA did not evaluate uses and potential exposure pathways which are not, by statute, covered by TSCA, such as food packaging. Past assessments, including the U.S. Consumer Product Safety Commission's (CPSC) risk assessment found that DINP exposure comes primarily from diet for women, infants, toddlers, and children. It is possible that DINP could pose risks to human health through uses or exposure pathways that are not regulated under TSCA. While EPA is preliminarily concluding in this draft risk evaluation that only three TSCA conditions of use significantly contributes to its draft unreasonable risk finding for DINP, this conclusion cannot be extrapolated to form conclusions about uses of DINP that are not subject to TSCA, and that EPA did not evaluate.
Next Steps
Under TSCA, manufacturers can request that EPA conduct risk evaluations on chemicals they manufacture. EPA received and granted manufacturer requests for risk evaluations of DINP and for diisodecyl phthalate (DIDP) in 2019. EPA released the draft risk evaluation for DIDP in May 2024 and requested peer review on the DINP human health hazard assessment at that time. The Science Advisory Committee on Chemicals (SACC) is currently engaged in peer review of these documents. EPA held a virtual public meeting of the SACC to consider and review these draft documents from July 30 - August 1, 2024, and plans to release the report from this meeting in October 2024. Therefore, the human health hazard assessment in this draft risk evaluation is the same draft version EPA submitted to the SACC.
DINP has the potential to cause effects on the developing male reproductive system commonly known as phthalate syndrome. Therefore, EPA is including DINP in its cumulative risk assessment along with five other phthalate chemicals that also have the potential to cause phthalate syndrome. Notably, assessments by Health Canada, U.S. CPSC, European Chemicals Agency, European Food Safety Authority, and the Australian National Industrial Chemicals Notification and Assessment Scheme have reached similar conclusions about the health effects of DINP.
Upon publication of the Federal Register notice, EPA will accept public comments on the draft documents for 60 days via docket EPA-HQ-OPPT-2024-0073 at www.regulations.gov. EPA will use feedback received from public comments to inform the final risk evaluation.
EPA will host a public webinar on Thursday, September 26, 2024, at 2:00 p.m. ET providing an overview of the risk evaluation and an opportunity for participants to share comments. Register for the webinar here. If you would like to make a comment during the webinar, please email Sarah Soliman at soliman.sarah@epa.gov by September 23 at 5:00 p.m. ET. All comments will have a time limit of 3 minutes. If you require accommodations, please email soliman.sarah@epa.gov by September 19 at 5:00 p.m. ET.