EPA’s recent draft risk evaluation of formaldehyde is a concerning new direction in the Agency’s implementation of the Toxic Substances Control Act (TSCA). Formaldehyde is a known carcinogen, with people routinely exposed through its use in composite wood products, plastics, paints, adhesives, and sealants. While EPA’s recent risk evaluation does find that formaldehyde presents an unreasonable risk to human health, it vastly understates the extent of that unreasonable risk. If adopted, this approach will set a dangerous precedent for future regulatory action under TSCA by accepting serious risks to people’s health.
For example, EPA’s own estimates of high risks from numerous industrial uses of formaldehyde were disregarded and downplayed in EPA’s risk determination for formaldehyde. For worker exposure scenarios, EPA applied a benchmark of one cancer case per 10,000 workers exposed to identify high–risk formaldehyde uses. This means that any use of formaldehyde where cancer risks are equal to or greater than 1-in-10,000 is considered high risk. In its draft risk evaluation, EPA found that 46 of 49 occupational exposure scenarios, also called conditions of use (COUs), exceeded the benchmark. However, EPA concluded that worker cancer risks were found to exceed the benchmark for only one of 49 COUs examined, directly contradicting its own scientific findings for 45 other COUs.
EPA also applied a scientifically unsupported conclusion that it had “less certainty” regarding the unreasonable risk of non-cancer respiratory effects for many formaldehyde uses to downplay these health risks. EPA used this phrasing even when the estimated formaldehyde exposures exceeded the level identified by EPA to cause adverse lung effects in humans – which actually indicates high certainty of unreasonable risk.
How EPA determined unreasonable risk in past risk evaluations
Until formaldehyde, EPA’s risk evaluation roadmap was clear:
- First, EPA estimates “central tendency” and “high-end” exposures to workers and consumers. The high-end estimates are intended to address TSCA’s requirement to assess risks for people who have greater exposures than others.
- Second, EPA estimates toxicity values for cancer and non-cancer effects, and establishes “benchmarks” for judging whether risks of cancer and non-cancer effects are too great.
- Third, EPA calculates risks of health effects by combining exposure estimates with the toxicity values for each use of the chemical, considering both central tendency and high-end exposures.
- Fourth, EPA compares the central tendency and high-end risks to the benchmark risk values, and identifies any uses with risks greater than the benchmarks as “contributors” to unreasonable risk for that chemical.
PRHE has voiced major concerns about how EPA calculates exposure, determines toxicity, and estimates risk, but EPA’s overall framework in TSCA risk evaluations was generally consistent and understood.
How EPA went backward in identifying unreasonable risks to formaldehyde
In the draft formaldehyde risk evaluation, EPA discarded many of these practices and instead made scientifically unsupported assumptions that resulted in understated risk and fewer formaldehyde uses being identified as contributors to unreasonable risk.
EPA’s first major departure from past practice was to only use central-tendency exposure estimates to identify uses that contribute to unreasonable risk, disregarding all high-end exposures and risks. As a result, EPA cannot protect workers and consumers with higher-than-usual exposures from the risks of formaldehyde, even though this is explicitly required by TSCA.
EPA’s second departure from previous practice was to make inappropriate comparisons between exposures estimated for industrial uses of formaldehyde with other exposure scenarios. Without justification, EPA said that it had “less certainty” of unreasonable risk when exposures are similar to the levels that have been previously measured in homes. An additional concern is that a “less certainty” conclusion may be used to justify looser regulation or no regulation at all of these uses.
These approaches are not consistent with the requirements of TSCA to use the best available science and ensure no unreasonable risks to the most highly-exposed people.
Implications for future TSCA implementation
If left uncorrected, EPA’s use of these unscientific practices will lead to a regulation that fails to address many unreasonable risks from formaldehyde. As a result, workers, consumers, and people who are more exposed or susceptible to harm from formaldehyde exposure will continue to be exposed to dangerous levels of formaldehyde that increase their risk of multiple adverse health outcomes, including cancer.
Even more concerning is that EPA’s approach to disregarding and downplaying high risks suggests a broader policy shift in TSCA implementation with important implications for other hazardous chemicals that EPA will evaluate in the coming months and years. EPA’s draft conclusions regarding formaldehyde set a dangerous precedent for future TSCA risk evaluations under which EPA can disregard high-risk exposures and downplay calculated high risks without justification, leading to less-protective regulations.
Many factors EPA used to weaken its formaldehyde conclusions are policy decisions that are not science-based. This is directly contrary to TSCA’s directives to rely on the best available science, and to eliminate any identified unreasonable risk. If EPA continues this approach, it will lead to more instances of high risks being dismissed and a failure to use TSCA as intended to eliminate those risks.
About the authors
Daniel Axelrad worked at the U.S. Environmental Protection Agency for 33 years in the Office of Pollution Prevention and Toxics and the Office of Policy. His areas of expertise include science policy, children’s environmental health, benefit-cost analysis and risk assessment. He has a bachelor’s degree in economics from Occidental College and a master’s in public policy from Harvard University.
Rashmi Joglekar, PhD, leads the Science, Policy & Engagement team at PRHE. She comes with a wealth of knowledge and understanding of how toxic chemicals impact susceptible populations and communities and is skilled in addressing these issues with decision-makers in Washington, DC. She completed her PhD in the Integrated Toxicology and Environmental Health Program at Duke University, specializing in neurodevelopmental toxicology.
