Helping EPA identify and protect those at greater risk from chemicals undergoing TSCA risk evaluation

Jennifer McPartland, Ph.D., is a Senior Scientist, and Lariah Edwards, Ph.D., is an EDF-George Washington University Postdoctoral Fellow

EPA Administrator Michael Regan recently completed a five-day “journey to justice” tour, highlighting communities across three US states that have been adversely affected by decades of chemical and air pollution. EPA’s focus on protecting those whose health is at greater risk, including communities disproportionately burdened by harmful chemical exposures, must be a priority in its implementation of the Toxic Substances Control Act (TSCA).

This week, EDF submitted comments to EPA to support the agency’s review of nine widely used substances currently undergoing TSCA risk evaluation: 1,3-butadiene, formaldehyde, and seven ortho-phthalates (phthalates). Our comments identify key groups that are at greater risk from these chemicals because they are more susceptible to their effects or are disproportionately exposed from environmental releases. Importantly, while our comments involved a broad review of the public literature, they do not capture all groups potentially at greater risk to exposure from these substances—and we strongly urge EPA to comprehensively identify all such groups using its information authorities as needed.

TSCA requires that EPA explicitly consider “potentially exposed or susceptible subpopulations” when evaluating and managing chemical risks—a major improvement made to the law when it was amended in 2016. The law defines potentially exposed or susceptible subpopulations as:

“a group of individuals within the general population identified by [EPA] who, due to either greater susceptibility or greater exposure, may be at greater risk than the general population of adverse health effects from exposure to a chemical substance or mixture, such as infants, children, pregnant women, workers, or the elderly.”

However, despite the new law’s explicit language, vulnerable subpopulations – including fenceline communities located near emitting facilities – were not adequately considered in the first ten risk evaluations conducted by the Trump administration. Additionally, scoping documents released during the previous administration for 1,3-butadiene, formaldehyde, and most of the phthalates failed to adequately identify specific potentially exposed or susceptible subpopulations the agency would consider in its risk evaluations.

1,3-Butadiene is an industrial chemical used primarily in the production of synthetic rubber; it is also used to make plastics and is present in petroleum-based fuels and cigarette smoke. People may be exposed to 1,3-butadiene from industrial releases into the environment and the workplace, as well as from automobile exhaust, cooking emissions, and the burning of wood, plastics, and rubber.

Formaldehyde is emitted directly into the air from industrial activity at sites such as power plants, manufacturing facilities, and incinerators. Significant exposure to formaldehyde occurs indoors, primarily because of its use in and subsequent release from various commercial and consumer products, including wood and particleboard-based furniture, carpeting, medicines, cosmetics, dishwashing liquids, carpet cleaners, and preservatives. Additionally, people are exposed to secondary formaldehyde formed through atmospheric reactions of other chemicals in the environment, including 1,3-butadiene.

Phthalates are a structurally similar class of multi-functional chemicals produced at high volumes. The seven phthalates currently undergoing TSCA risk evaluation include di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBzP), di-(2-ethylhexyl phthalate (DEHP), diisobutyl phthalate (DiBP), dicyclohexyl phthalate (DCPH), diisononyl phthalate (DiNP), and diisodecyl phthalate (DiDP). These chemicals are used in a wide variety of applications including PVC-based materials, food production and packaging, paints and coatings, medical devices, and personal care products. Given concerns for developmental toxicity, pregnant women and children are particularly susceptible to the effects of phthalate exposure. Additionally, research has shown that Black people are disproportionately exposed to phthalates via certain foods and personal care products.

Based on our review of the literature we recommend that EPA include the following potentially exposed or susceptible subpopulations in its ongoing risk evaluations:

• 1,3-Butadiene – Smokers, children exposed to secondhand tobacco smoke, persons with genetic differences that affect how their bodies metabolize 1,3-butadiene, workers in certain occupations, and fenceline communities.
• Formaldehyde – Smokers, e-cigarette users, persons with asthma, workers in certain occupations, and fenceline communities.
• Phthalates – Pregnant women, premature infants and young children, and Black people. Importantly, our review of the literature found limited information regarding fenceline exposures to phthalates. We urge EPA to fully assess potential risks resulting from such exposures.

TSCA requires that EPA comprehensively identify and consider groups at greater risk from exposure to chemicals undergoing TSCA risk evaluation. The Biden-Harris administration has also said it is committed to environmental justice. The agency has an important opportunity to help meet this commitment under TSCA by using its information authorities to identify and address groups at greater risk, including those at the fenceline.