US environmental regulators are inviting public scrutiny of 24 studies on a widely used fragrance ingredient after an administrative problem made them inaccessible through an agency database during an earlier consultation.
The studies concern HHCB, a synthetic musk also known as galaxolide. It is used in fragrances and household products including detergents, cleaners and air fresheners. The Environmental Protection Agency (EPA) considered the industry-submitted studies when preparing a draft assessment of the chemical, even though the public could not access them through the agency’s research database at the time.
The agency announced the new opportunity to comment on 13 November. A notice setting out the process was filed for public inspection that day and is scheduled for publication in the Federal Register on 16 November. The EPA says the comment period will close on 16 December.
The exercise is limited to the newly accessible material. It is not a reopening of the whole draft assessment, a new finding that the chemical is harmful, or a decision to restrict its use.
What changed
The original public comment period for the draft HHCB evaluation ran from 14 April to 15 June. During that period, the EPA identified an administrative issue in its Health and Environmental Research Online database that had made the 24 studies unavailable to the public.
The agency says the problem was resolved on 14 October and the studies are now accessible through the database. It plans to include a list of them in an HHCB data availability memorandum in the chemical’s public docket when the notice is published.
The distinction matters because the studies are not newly commissioned research. They had already formed part of the evidence available to the agency for its draft human health and environmental hazard assessment. The new comment opportunity is intended to let others examine that material in the context of the draft and respond before the evaluation is finalised.
Members of the public can identify the relevant record using docket number EPA-HQ-OPPT-2018-0430 on the US government’s regulations website. The agency intends to consider comments on the newly available material as it completes the evaluation.
What the draft found
HHCB was designated a high-priority substance for a US risk evaluation in December 2019. The EPA published its draft assessment in April 2026 for public comment and external scientific peer review.
In that draft, the agency preliminarily concluded that HHCB does not present an unreasonable risk to human health or the environment under the conditions of use it assessed. Those conditions include manufacturing, processing, distribution, commercial and consumer use, and disposal. The draft considers workers, consumers, the general population and ecological receptors.
That conclusion is provisional and applies to the uses covered by the assessment. The EPA did not evaluate uses outside the relevant chemicals law, including cosmetics, certain personal care products, medical devices and food additives. The draft’s conclusion therefore cannot be applied to those excluded uses.
Assessing risk involves more than identifying whether a substance could have an effect under some circumstances. Regulators also examine how exposure might occur and how much people or the environment could encounter under the uses being assessed. The draft includes long-term combined exposure scenarios for workers and consumers, including an infant scenario, as well as modelling and measured data concerning potential accumulation in fish.
The assessment describes uncertainties. It also notes that some initial ecological screening results raised questions that were considered alongside further modelling and measurements. The agency’s overall preliminary view was that the weight of the evidence did not indicate an unreasonable risk under the assessed conditions.
The environmental organisation Weaving Voices for Health and Justice has previously raised concerns about possible effects on hormones, reproduction and development, as well as the chemical’s presence in the Great Lakes. Those concerns are not evidence that a particular exposure has caused harm; they underline why the evidence and the assumptions used to assess it matter.
What happens next
For people preparing comments, the question is how the newly accessible studies relate to the draft assessment, rather than an invitation to restart every part of the review. The EPA has not said that making the documents available changes its preliminary conclusion.
The agency expects to consider the feedback as it works towards a final risk evaluation. Only a final determination would establish the outcome of that evaluation. If an unreasonable risk were ultimately identified, the law would require a separate risk-management stage, with an opportunity to comment on any proposed restrictions. Neither that outcome nor a ban has been announced.
