Recently, the U.S. Environmental Protection Agency (EPA) released a preliminary draft risk assessment for Dicyclohexyl Phthalate (DCHP). The assessment indicates that under certain conditions of use, DCHP poses an unreasonable risk to worker health.
DCHP is primarily used as a plasticizer in adhesives, paints, coatings, and plastic resins, and also serves as a stabilizer in the manufacturing of various products, including printing inks and rubber goods. While the EPA's draft assessment confirms that DCHP does not pose an unreasonable risk to the environment, it raises significant concerns regarding the exposure levels of workers involved in its manufacture and processing.
EPA is preliminarily determining the following COUs, based on the DCHP individual analysis and the relative potency factor analysis, significantly contribute to the unreasonable risk to workers:
- Manufacturing – domestic manufacturing;
- Processing – incorporation into formulation, mixture, or reaction product – adhesive and sealant chemicals in adhesive manufacturing;
- Processing – incorporation into formulation, mixture, or reaction product – plasticizer (adhesive manufacturing; paint and coating manufacturing; and printing ink manufacturing);
- Processing – incorporation into formulation, mixture, or reaction product – stabilizing agent (adhesive manufacturing; asphalt paving, roofing, and coating materials manufacturing; and paints and coating manufacturing);
- Industrial use – finishing agent – cellulose film production;
- Industrial use – inks, toner, and colorant products (e.g., screen printing ink);
- Industrial use – paints and coatings;
- Commercial use – inks, toner, and colorant products (e.g., screen printing ink); and
- Commercial use – paints and coatings.
Additionally, the EPA is preliminarily determining that the following COUs do not significantly contribute to the unreasonable risk:
- Manufacturing – importing;
- Processing – incorporation into article – plasticizer in plastics product manufacturing and rubber product manufacturing;
- Processing – repackaging (e.g., laboratory chemicals);
- Processing – recycling;
- Distribution in commerce;
- Industrial use – adhesives and sealants (e.g., computer and electronic product manufacturing; transportation equipment manufacturing);
- Industrial use – other articles with routine direct contact during normal use including rubber articles; plastic articles (hard) (e.g., transportation equipment manufacturing);
- Commercial use – adhesives and sealants;
- Commercial use – building/construction materials not covered elsewhere;
- Commercial use – laboratory chemicals;
- Commercial use – other articles with routine direct contact during normal use including rubber articles; plastic articles (hard);
- Consumer use – adhesives and sealants;
- Consumer use – other articles with routine direct contact during normal use including rubber articles; plastic articles (hard);
- Consumer use – other consumer articles that contain dicyclohexyl phthalate from: inks, toner, and colorants; paints and coatings; adhesives and sealants (e.g., paper products, textiles, products using cellulose film, etc.); and
- Disposal.
The EPA encourages individuals, governments, non-governmental organizations, academic and research institutions, and the private sector to comment on the DCHP risk assessment draft. Public comments must be submitted by March 10, 2025. If the final assessment confirms that DCHP poses an unreasonable risk, the EPA will take appropriate regulatory measures to mitigate this risk.
