New Air Monitoring Finds Elevated Levels of Cancer-Causing Ethylene Oxide in Salinas, Puerto Rico
Findings come as EPA and Steri-Tech reached a proposed agreement to address Clean Air Act violations, but local communities will remain vulnerable
Contacts
New monitoring results commissioned by Earthjustice show that levels of ethylene oxide (EtO), a cancer-causing chemical, remain elevated in the air in Salinas, Puerto Rico. The findings come as the U.S. Environmental Protection Agency (EPA) seeks court approval of a settlement with Steri-Tech, Inc., a commercial sterilizer in Salinas that uses EtO gas in its sterilization operations. The proposed settlement provides some additional protections but fails to adequately address past violations or prevent recurrence.
The study sheds light on the ongoing dangers of EtO emissions in Salinas. The July 2026 monitoring detected EtO across La Margarita and Brisas del Mar neighborhoods to the west and northwest of Steri-Tech. EtO concentrations measured downwind of the facility were substantially higher than concentrations measured upwind, indicating that emissions from Steri-Tech are contributing to elevated EtO levels in the surrounding community.
EtO is highly toxic, even at low concentrations. Exposed community members are at an increased risk of health harms from ethylene oxide, including breast and blood cancers, pregnancy loss, developmental challenges, and other impacts.
“The new monitoring underscores the need for stronger, enforceable protections for the Salinas community,” said Deena Tumeh, senior attorney at Earthjustice. “Any final agreement must address all sources of emissions and require transparent, publicly accessible monitoring to demonstrate whether those protections are working.”
Chronic exposure to EtO causes serious health risks at concentrations far below levels measured by Earthjustice in 2026 and EPA in 2022. EPA’s modeling and monitoring in 2022, and Earthjustice’s monitoring in 2025 and 2026, consistently show average airborne ethylene oxide concentrations in the communities surrounding Steri-Tech that are multiples greater than what EPA established as an acceptable risk.
More than 14 million people in the United States and its territories, including Puerto Rico, live near sterilizer facilities that emit ethylene oxide, one of the most toxic air pollutants regulated by EPA. With seven sterilizers on the island, Puerto Rico faces a disproportionate impact from EtO pollution from sterilizers.
“The study is conclusive and confirms what the EPA previously – that we, the residents of Salinas, are exposed to a carcinogenic chemical that has been making us sick for years. We demand an immediate end to the pollution of our air,” said Victor Alvarado of Comité Diálogo Ambiental.
“The agencies and the City of Salinas cannot turn a blind eye. The agreement filed by the EPA is unacceptable. We demand greater controls to protect our communities,” said Ruth Santiago, who also serves as attorney for Comité Diálogo Ambiental.
A proposed deal that falls short
In June 2025, the EPA, represented by the U.S. Department of Justice (DOJ), sued Steri-Tech in federal court, alleging that the company violated federal and Puerto Rico law by failing to operate its air pollution control equipment, leading to unlawful EtO emissions, among other violations. In September 2026, EPA and DOJ announced a proposed settlement with Steri-Tech that would resolve these claims.
The proposed agreement would require a 99.99% ethylene oxide reduction of EtO from sterilization chamber vents, additional reporting, and stipulated penalties. But significant gaps remain. The 99.99% control requirements apply to one part of the sterilization process but leaves others unchecked. Despite the facility’s alleged past violations, the proposal does not require direct monitoring of EtO emissions or ambient air monitoring of EtO around the facility.
“Steri-Tech was mis-operating its air pollution control equipment for years and putting people at serious risk,” said Lillian Zhou, associate attorney with Earthjustice. “The harm to community members’ health cannot be undone. The bare minimum EPA must do to protect people moving forward is to ensure that Steri-Tech controls all of its EtO emissions and publishes all compliance and monitoring reports to allow the public to stay informed.”
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