This story is a collaboration between Grist and el Centro de Periodismo Investigativo. It was supported by the Fund for Investigative Journalism. Lee esta nota en español.
Henry Morales’ Encounter with Ethylene Oxide
Henry Morales woke up in the emergency room in Salinas, Puerto Rico, not knowing where he was. A doctor appeared beside him and gestured toward a dark-haired woman with a worried expression. “Do you know who this is?” he asked. Morales blinked, but didn’t answer. Words seemed to belong to some faraway place, and he was too tired to reach for them. “Who is this?” the doctor repeated. After a few minutes, Henry heard himself respond. “That is my wife,” he said.
The memory of what led him to the hospital returned in blurry snapshots that he continues to piece together more than 20 years later. He’d been working a regular shift at Steri-Tech, a company that sterilizes medical devices, where he’d been an operator technician for five years. His job was to move boxes of medical supplies in and out of the sterilization chambers and to check the small vials of biological material placed in each box as a way to verify that it had all been successfully sterilized.
In the normal course of Morales’ work, he typically wore a respirator to protect himself from the toxic gas, ethylene oxide, used to sterilize the medical products. On the day of his hospitalization, Morales and several coworkers had just removed a pallet of sterilized equipment from the chamber. Once the door to the chamber was closed, Morales and the others took off their gas masks, as was standard. Morales noticed that one vial of biological material was missing. He identified the box he’d overlooked and to be sure that it was sterilized, he opened it.
One memory that has always remained vivid for Morales is what he smelled when he opened the box. “Dulce,” Morales said to describe the scent; it was sweet, unlike anything he’d smelled before. Steri-Tech uses the gas ethylene oxide — which has a unique ability to penetrate porous surfaces and destroy microorganisms without damaging heat-sensitive materials like heart valves, pacemakers, catheters, and intubation tubes — to fumigate the products it sterilizes. It’s what Morales smelled when he opened the box.
As he arranged the box back on the pallet, Morales began to feel lightheaded, and he stumbled through the rest of his shift. Once he clocked out, anxious to pick up his wife and go home, he made his way to his car. As soon as he opened the door, his “mind went out.”
A coworker found him convulsing with a seizure in the driver’s seat. His arm was lodged between the seat and the center console, his shoulder dislocated. The coworker quickly called an ambulance, and Morales was rushed to the hospital, where medical staff ran MRI and CT scans and found that a portion of the left side of Henry’s brain had died. He was diagnosed with epilepsy and prescribed the anti-seizure drug Dilantin, which he continues to take four times a day.
When they spoke after the accident, Steri-Tech founder and CEO Jorge Vivoni assured Morales that the plant was safe. According to Morales, Vivoni told him that his condition was the result of congenital epilepsy, not workplace exposure. But during his recovery, Morales decided to read about the effects of inhaling ethylene oxide and recognized that he had experienced all the symptoms of acute exposure: headaches, dizziness, twitchiness, and seizures.
“Henry was never sick,” his wife, Jannette, said. “Everything changed that day. Before that, he was a healthy man.”
The Dangers of Ethylene Oxide
Ethylene oxide has the ability to damage DNA structures — what makes it both an effective sterilizer and a carcinogen that’s the second most toxic federally regulated air pollutants.
At the time of his accident in 2003, the dangers of breathing in ethylene oxide were not fully known, so neither Morales nor any of his peers consistently wore protective gear while working. Ethylene oxide is a volatile organic compound, a synthetic gas that breaks down over the course of a few months after it’s released into the atmosphere. Research since Morales’ incident has shown that ethylene oxide can damage DNA structures — an ability that makes it both an effective sterilizer and a carcinogen.
When it is inhaled by humans, it can irritate the respiratory pathways and increase the risk of cancer and negative health effects in unborn children. About 50 percent of the medical equipment in the U.S. and its territories is sterilized this way.
In 2016, the Environmental Protection Agency published its analysis of an epidemiological study of more than 18,000 workers in sterilization facilities that assessed the cancer risk associated with the inhalation of ethylene oxide. The researchers found the chemical to be 30 times more toxic to adults and 60 times more toxic to children than previously known, making it the second most toxic federally regulated air pollutant. The study found links between the exposure to ethylene oxide and multiple types of cancer, including lymphoma and female breast cancer.
In response to the EPA’s analysis, some communities in the continental U.S. began to rally against the sterilizers in their backyards. In 2019, a wealthy suburb of Chicago even managed to shut one down.
Ethylene Oxide Facts
- What is ethylene oxide? Ethylene oxide is a colorless and odorless toxic gas used to sterilize medical products, fumigate spices, and manufacture other industrial chemicals. According to the Food and Drug Administration, approximately half of all sterile medical devices in the U.S. are disinfected with ethylene oxide.
- What are the sources of ethylene oxide exposure? Industrial sources of ethylene oxide emissions fall into three main categories: chemical manufacturing, medical sterilization, and food fumigation.
- What are the health effects of being exposed to ethylene oxide? Ethylene oxide, which the EPA has labeled a carcinogen, is harmful at concentrations above 0.1 parts per trillion if exposed over a lifetime. Numerous studies have linked it to lung and breast cancers as well as diseases of the nervous system and damage to the lungs. Acute exposure to the chemical can cause loss of consciousness or lead to a seizure or coma.
- How is the EPA regulating ethylene oxide? The EPA finalized regulations for ethylene oxide emissions from the sterilization industry earlier this year. The new rule requires companies to install equipment that minimizes the amount of the chemical released into the air. However, it does not address emissions from other parts of the medical device supply chain, such as warehouses and trucks, and it is being challenged in court.
But it wasn’t until 2022 that Puerto Ricans learned about the toxic emissions that they worked with and lived near. That summer, the EPA released a modeling analysis finding the island to be an epicenter for ethylene oxide pollution. Four of Puerto Rico’s seven sterilization plants exceed the agency’s cancer risk threshold. The Steri-Tech facility where Morales worked, which has been in operation since 1986, was determined to be the most dangerous sterilizer in the U.S. and its territories. In contrast, the modeling showed that none of California’s 12 sterilizers violated federal standards.
The EPA scheduled a community meeting to be held that August in Salinas, at which Jose Font, the agency’s deputy director of its Caribbean division, would answer questions about ethylene oxide and the community’s exposures. On the night of the meeting, the community center was packed with people who wanted to know why they were only just finding out about the toxic emissions they had lived next to for three decades. Mistrust of local and federal authorities runs deep in the municipality of 25,000, where more than half the population lives in poverty and families bring home on average $20,000 per year. Instead of apologizing, Font mischaracterized the risks to residents’ long-term health. Referring to the 2016 EPA study, he assured the community members that they could only develop cancer from the emissions if exposed for 70 years.
Air monitoring by the EPA in the vicinity of Steri-Tech showed that nearby residents were being exposed to levels of ethylene oxide more than 1,000 times above the agency’s threshold for acceptable risk.
