An official website of the United States government.

Assessing and Managing Chemicals under TSCA

Risk Evaluation for 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB)

EPA designated 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB) as a high priority chemical 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:


Background on HHCB

HHCB (CASRN 1222-05-5) is a viscous, or thick, liquid . The primary use of HHCB is as an odor agent for fragrances, for instance, air care products and cleaning products.  Total production volume of HHCB in 2015 was between 1 million and 10 million pounds.

Uses of HHCB

In the final scope, EPA identified conditions of use associated with the manufacturing (including importing); processing; distribution in commerce; commercial and consumer uses; and disposal of HHCB, for example:

  • Processing to incorporate HHCB into a formulation, mixture, or reaction products, and to incorporate HHCB into articles;
  • In air care products (e.g., aroma chemicals, air fresheners in motor vehicles, scented candles, aerosols and spays);
  • In cleaning and furnishing care products (e.g., all-purpose cleaners and bathroom cleaners);
  • In laundry products (e.g., laundry detergent and fabric softener);
  • In plastic and rubber products; and
  • In paper 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 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.

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.