Risk Evaluation for Dicyclohexyl Phthalate (DCHP)

In December 2024, EPA released the draft risk evaluation for dicyclohexyl phthalate (DCHP) for public comment and peer review. EPA designated DCHP as a High-Priority Substance in December 2019 and the chemical is currently undergoing risk evaluation.

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

On this page:

Risk Evaluation Findings
Background on DCHP
Conditions of Use of DCHP
Recent Activities and Opportunities for Public Comment
Draft Risk Evaluation and Supporting Documents

Risk Evaluation Findings

In the draft risk evaluation, EPA preliminarily determined that DCHP presents an unreasonable risk of injury to human health for workers from inhalation exposure. Exposure to DCHP can harm the developing male reproductive system, in a phenomenon known as “phthalate syndrome” (e.g., decreased fetal testicular testosterone, male reproductive tract malformations, male nipple retention, and decreased male fertility).

Workers may be exposed to DCHP when making products or otherwise using DCHP in the workplace. When it is manufactured or used to make products, DCHP can be released into the water where most of it will end up in the sediment at the bottom of lakes and rivers. If released into the air, DCHP will attach to dust particles and be deposited on land or into water. Indoors, DCHP 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 DCHP.

EPA did not specifically evaluate uses and potential exposure pathways which are not, by statute, covered by TSCA, such as food packaging. Past assessments of DCHP have concluded that DCHP does not pose risk to human health, or the environment, based on its concentration in products and the environment. Notably, both the U.S. Consumer Product Safety Commission’s and Health Canada’s risk assessments included consideration of exposure from children’s products as well as from other sources such as personal care products, diet, consumer products, and the environment. EPA preliminarily shows that DCHP does not pose unreasonable risk to the environment, the general population or consumers.

Background on DCHP

DCHP (CASRN 84-61-7) is a granular solid at room temperature. The primary use for DCHP is as a plasticizer in adhesives and plastic and rubber products and resins. Information from the 2016 Chemical Data Reporting (CDR) for DCHP indicates the reported production volume is between 500 thousand and 1 million lbs/year.

Conditions of Use of DCHP

In the final scope, EPA identified conditions of use associated with the importing; processing; distribution in commerce; industrial, commercial and consumer uses; and disposal of DCHP, for example:

As a plasticizer in adhesive, paint and coatings, plastic products, rubber products, and plastic resin manufacturing;
As a phlegmatizer (to improve safety and stability) in a variety of peroxide curing agent mixtures used in industrial and commercial applications, such as roofing systems, road markings, coatings, adhesives and other composites;
In industrial and commercial automobile and aerospace products;
For laboratory chemicals; and
In commercial and consumer products, such as adhesives and sealants, and plastic and rubber products.

The above listed conditions of use are ways that a person or the environment could be potentially exposed to this chemical. 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.

Recent Activities and Opportunities for Public Comment

In December 2024, EPA released the draft risk evaluation for DCHP for public comment and peer review. EPA will accept public comments on the draft risk evaluation for 60 days following publication in the Federal Register via docket EPA-HQ-OPPT-2018-0504 at regulations.gov.

EPA will hold a virtual public meeting of the Science Advisory Committee on Chemicals (SACC) to discuss EPA’s data, methods, models, and approaches for the evaluations of benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DIBP), and DCHP. This includes the cross-phthalate technical support documents for human health benchmark dose analysis, cancer analysis, and cumulative risk analysis. The SACC meeting will take place in the spring of 2025. View the SACC website for more information on these meetings.

In August 2020, EPA published a 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 April 2020 and took public comments on the draft document.

Read the final scope of the risk evaluation for this chemical and EPA’s response to comments on the draft scope.
View the docket for this chemical, EPA-HQ-OPPT-2018-0504 on regulations.gov.

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

Draft Risk Evaluation and Supporting Documents

Read the Federal Register notice.

View the supporting documents in docket EPA-HQ-OPPT-2018-0504.