The organizations Earthjustice and the Comité Diálogo Ambiental reported that an air quality monitoring study conducted in Salinas between July and September found high concentrations of ethylene oxide (EtO), a chemical with carcinogenic effects. The results emerged at the same time that the U.S. Environmental Protection Agency (EPA) filed a proposed settlement in federal court to resolve alleged Clean Air Act violations by the company Steri-Tech, Inc. Earthjustice, which provides legal support to communities, commissioned the study from scientist Rick Peltier of Dirigo Innovations, who is also a professor at the University of Massachusetts Amherst.
Samples were taken in the communities of La Margarita and Brisas del Mar, west and northwest of Steri-Tech. Peltier said EtO concentrations measured downwind of the facility, toward the community, were substantially higher than those measured upwind, indicating that Steri-Tech's emissions contribute to elevated EtO levels in the surrounding community. He explained that EtO concentrations in Salinas averaged 2.2 parts per billion (ppb).
Chronic exposure to EtO carries serious health risks at concentrations even lower than those detected by Earthjustice in 2025 and 2026 and by the EPA in 2022. The EPA's 2016 IRIS assessment sets 0.011 ppb as the average concentration a person can breathe over 70 years without exceeding a 1-in-10,000 cancer risk.