In December 2025, the Environmental Protection Agency (EPA) published a memorandum proposing to revise its final risk evaluation for formaldehyde. As part of its proposed changes, EPA asserts that there is a threshold below which formaldehyde exposure poses no cancer risk, and claims that maintaining formaldehyde exposure levels low enough to prevent acute sensory irritation will also protect against cancer and non-cancer chronic health effects.
We submitted comments to EPA urging it to withdraw the memorandum, explaining that these assumptions are not supported by the best available science and run contrary to decades of cancer assessment guidelines and EPA’s own peer-reviewed findings. Further, we explain that these methodological changes will undermine EPA’s future risk management actions by artificially devaluing public health benefits. Specifically, these assumptions will skew the assessment of benefits and costs associated with EPA's upcoming formaldehyde risk-management rule, effectively zeroing out quantified health effects.
By asserting that formaldehyde is a threshold pollutant, EPA erases any cancer-related benefits associated with reducing formaldehyde exposure below this threshold. In ceasing to calculate the effects of cancer and non-cancer chronic effects associated with sustained formaldehyde exposure, the agency ensures any benefits of reducing these risks will go unconsidered. And by choosing to evaluate only acute, non-cancer risks, for which EPA has no direct measure of the risk of adverse health outcomes, EPA tees up a risk-management analysis that finds no quantified or monetized benefits from reducing formaldehyde exposure at all.