EPA Begins Public Comment Period On Updated Draft Risk Calculation Memorandum For Formaldehyde

On December 3, 2025, the U.S. Environmental Protection Agency (EPA) announced the availability of and solicited public comment on an Updated Draft Risk Calculation Memorandum (Draft Memorandum) to inform a revised draft risk evaluation for formaldehyde under the Toxic Substances Control Act (TSCA). 90 Fed. Reg. 55726. EPA states that after further consideration of comments raised during the scientific peer review process, it is reconsidering the use of certain hazard values in the formaldehyde risk evaluation. The Federal Register notice, Draft Memorandum, and materials included in the docket provide the science and science policy basis for determining how the revised draft inhalation point of departure (POD) impacts the corresponding draft margin of exposure (MOE) estimates and the risk determination. EPA notes that although it is also providing a revised draft occupational exposure value, it "is not changing its position that formaldehyde poses unreasonable risk of injury to human health." As such, EPA continues work on a proposed risk management rule for formaldehyde as required by TSCA to ensure statutory deadlines are met and necessary protections are not delayed. According to the notice, EPA is also seeking additional information specific to how formaldehyde is manufactured and used that may inform the risk management of formaldehyde. After public comment, EPA will determine if the proposed revisions discussed in the notice warrant updating the formaldehyde risk evaluation. Comments are due February 2, 2026.

Draft Memorandum

EPA states in its December 3, 2025, press release, that under the Biden Administration, EPA's Office of Chemical Safety and Pollution Prevention (OCSPP) programs, including the Office of Pollution Prevention and Toxics (OPPT) and the Office of Pesticide Programs (OPP), "were directed to rely upon and use the chronic non-cancer reference concentration (RfC) and cancer inhalation unit risk (IUR) that were being developed and were subsequently finalized by the Integrated Risk Information System (IRIS) program." Consistent with statutory obligations and President Trump's Executive Order (EO) 14303, "Restoring Gold Standard Science," the Trump EPA "is committed to the highest standards of scientific integrity and reliance on the best available scientific information." As such, OCSPP has re-evaluated the use of the IRIS cancer IUR in the formaldehyde risk evaluation. EPA has also considered the peer-review record, including comments from the Science Advisory Committee on Chemicals (SACC), the Human Studies Review Board (HSRB), and National Academies of Sciences, Engineering, and Medicine (NASEM). Following their recommendations and focusing on the science, EPA is issuing the Draft Memorandum, which was used as the basis for the revised draft risk evaluation for formaldehyde.

According to EPA, consistent with the SACC recommendations, it is supplementing the endpoints used in the TSCA risk evaluation to determine human health effects from formaldehyde. EPA states that in its review of the draft formaldehyde risk evaluation, SACC "was generally critical of the agency's reliance on cancer and non-cancer hazard values for formaldehyde inhalation presented in the draft IRIS Toxicological Review of Formaldehyde — Inhalation."

In the Draft Memorandum and the documents that rely on the information presented in it, EPA proposes that the best available science supports using sensory irritation as the most sensitive endpoint for determining human health effects from inhalation exposures. Managing risks from acute sensory irritation will be protective against other health effects, including cancer. According to EPA, this approach is supported by the recommendations of SACC and other federal advisory committees. EPA notes that because the Draft Memorandum implements recommendations from the multiple peer review bodies, additional peer review is not necessary.

Request for Comment

EPA states in the Federal Register notice that it seeks feedback on the Draft Memorandum and associated documents and encourages interested parties to comment on the draft documents. To the extent possible, EPA asks commenters to cite any public data related to or that support comments provided, and to the extent permissible, describe any supporting data that are not publicly available.

EPA welcomes specific input on each section of the Draft Memorandum and related supported documents. EPA states that it will also consider the following information for risk management of formaldehyde:

• Personal protective equipment (PPE) use, including the type of PPE worn for different workplace activities and task durations under the conditions of use (COU), circumstances where it may not be practicable for potentially exposed persons to wear PPE, and feasibility of exposure reduction to formaldehyde sufficient to address the unreasonable risk, including associated monitoring practices to assess exposure reductions;

• Dermal and respiratory workplace controls, such as eliminating dermal contact, engineering controls, and administrative controls that could address the unreasonable risk; and

• Emission factors and weight fractions for commercial and consumer products or articles along with the respective uses and applications, and threshold or de minimis concentrations in products or articles.

Next Steps

EPA plans to convene "expeditiously" a Small Business Advocacy Review (SBAR) Panel to obtain input on a proposed risk management rule. EPA states that it "will rely on gold standard science and take the Updated Draft Risk Calculations and Revised Draft Risk Evaluation into account when drafting a proposed risk management rule to meet statutory deadlines and ensure health protections."

Commentary

EPA's Draft Memorandum updating risk calculations for formaldehyde is noteworthy for several reasons. First, it reflects a sea-change from EPA's past practice of effectively defaulting to IRIS values in TSCA risk evaluations. In this document, it is important to note that EPA explicitly rejects the IRIS IUR as the POD for formaldehyde, explaining why it now views its proposed, updated POD (0.3 parts per million (ppm)) as the best available science. It also brings EPA's assessment closer to other competent authorities around the world and closer to the SACC comments. Second, it is evidence that this Administration is willing to depart from past scientific conclusions that EPA no longer views as the best available science. This is important as, to our knowledge, this is the first clear acknowledgement by OPPT that an IRIS value does not meet the scientific standards under TSCA. Finally, it puts the POD in a range that makes sense based on real-world exposures to formaldehyde. The POD in the January 2025 final risk evaluation was so low and formaldehyde exposures from biogenic and secondary (e.g., combustion) sources are so prevalent, one would expect nasopharyngeal cancers to be much more common than they are. Although this POD is quite a bit higher than the one in the original risk evaluation, an occupational exposure limit (OEL) based on this POD is still lower than the Occupational Safety and Health Administration (OSHA) standard, so some workplaces will have to adapt, but the TSCA OEL will no longer be orders of magnitude lower than the OSHA OEL.

There will undoubtedly be robust comments on this Draft Memorandum. Although EPA indicates that it will review public comments to determine whether or not the risk evaluation should be updated, some stakeholders will likely consider the updated calculations themselves to be a revision of the risk evaluation. Of note, EPA also concurrently published redlined versions of the hazard assessment, human health risk assessment, executive summary, and risk determination to reflect how the updated calculations would impact the January 2025 final risk evaluation. Given the current risk evaluation framework rule's mandate to issue a single determination for a substance, this updated calculation would not impact the overall conclusion for formaldehyde — it will still present an unreasonable risk. EPA has, however, separately proposed to update its approach with respect to risk determinations, opening the door to a revised formaldehyde risk evaluation that concludes certain uses present unreasonable risk while others do not. If EPA does not apply the use-specific approach in revising the risk determination — and does not issue corresponding "no unreasonable risk" orders for certain COUs — stakeholders that disagree with the updated POD may have to wait for the final risk management rule to challenge EPA's updated scientific conclusion.

Science aside, the issuance of this Draft Memorandum is also likely to raise some process questions. Both the current 2024 procedural framework rule for risk evaluations and the 2025 proposed update include provisions for how and when EPA will undertake revisions to final TSCA risk evaluations. The 2024 rule, for example, suggests that re-prioritization is required to make changes to final risk evaluations that are not "in the interest of protecting human health or the environment...". The 2025 proposed update, in contrast, would seem to allow revision or supplementation so long as EPA follows procedural requirements like publication of a new draft risk evaluation, solicitation of public comment, and peer review as appropriate. Although EPA's notice generally appears to avoid characterizing the Draft Memorandum and associated documents as a revised draft risk evaluation for formaldehyde, the preamble indicates that next steps could be to "announce the availability of the...Revised Final Risk Evaluation for Formaldehyde...".

The deadline for risk management is also looming. The formaldehyde risk evaluation was originally published in final on January 3, 2025, establishing a January 3, 2026, statutory deadline for proposing a risk management rule. As noted earlier, EPA indicated that it still intends to convene an SBAR panel — an important step in developing proposed regulations that could have a significant impact on a substantial number of small businesses. Implementing this process, however, will be challenging with the risk evaluation — the underlying basis for the rule — still in flux. For comparison, EPA's SBAR panels on other TSCA Section 6 rules took anywhere between two and a half to nine and a half months from the date convened to the date completed. If the SBAR panel does not convene until EPA has published an updated draft and/or final risk evaluation, it may be quite some time before we see the proposed risk management rule for formaldehyde.