EVERY DAY IN THE BAY AREA and across California, workers step into sterilization facilities, unaware they may be inhaling something that could one day make them gravely ill. The culprit is ethylene oxide (EtO), a colorless, odorless gas used to sterilize nearly half of all medical equipment in the United States. Although the chemical plays a critical role in ensuring hospitals have sterile surgical tools and pharmaceutical supplies, it comes with a steep human cost. Classified by the Environmental Protection Agency (EPA) as a known human carcinogen, EtO has been silently threatening thousands who work in and around the sterilization facilities in California.
It’s time for the Occupational Safety and Health Administration (OSHA) to take responsibility and protect these workers. Without immediate, science-based reforms to current exposure limits, employees and surrounding communities will continue to breathe unsafe air — air that regulators already know can cause cancer.
The silent threat in the Bay Area’s air
Ethylene oxide is highly effective for sterilizing instruments that can’t be cleaned using heat or steam, making it indispensable in the medical industry. However, long-term exposure to this gas has devastating consequences. The EPA and the Centers for Disease Control and Prevention (CDC) have both confirmed that breathing EtO over time can lead to breast cancer, leukemia, lymphoma, and multiple myeloma, among other conditions. Even brief exposures to higher concentrations of EtO can trigger respiratory irritation, dizziness, and neurological symptoms.
According to the Food and Drug Administration (FDA), nearly 50% of all U.S. medical devices are sterilized with EtO each year. This means a vast network of sterilization plants, many located in or near residential areas, releases this chemical into the air as part of their operations.
California is home to 15 sterilization facilities, including three located in the Bay Area. Thousands of residents, as well as hundreds of schools and childcare centers, are situated within a 5-mile radius of these plants. The distribution of risk is inequitable; communities nearest to these facilities are disproportionately composed of people of color, low-income households, and families with limited English proficiency. A similar pattern is observed in Los Angeles, where the Sterigenics facility places nearly 100,000 residents within a 5-mile exposure zone. In Willowbrook, Illinois, and Laredo, Texas, comparable facilities have been documented emitting EtO at concentrations that elevate cancer risks to levels dozens of times above federal safety thresholds. Given these elevated risks to surrounding neighborhoods, the potential danger to workers within these facilities is likely even greater.
Outdated rules are failing workers
Despite mounting scientific evidence, OSHA’s permissible exposure limits (PELs) for EtO haven’t changed since 1984. That was before researchers fully grasped the toxicity and hazards of this gas to human health.
While the EPA now recognizes that EtO is far more carcinogenic than previously believed and plans to gradually lower environmental emissions to 0.1 part per million by 2035, OSHA’s workplace limit remains at 1.0 ppm, which is two to 10 times higher than experts consider unsafe.
This gap between environmental and occupational standards means that while agencies warn about health risks, the workers closest to the pollution’s epicenter remain underprotected by outdated rules. This disconnect is deadly, not just bureaucratic.
California needs stronger OSHA regulations
OSHA must step up to protect workers in California and across the country, necessitating an immediate update to its ethylene oxide safety standards. This includes aligning exposure limits with current scientific understanding and requiring continuous, real-time air monitoring in and around facilities that use EtO. No less important, the organization must mandate high-efficiency ventilation, leak-detection systems, and provide workers with proper protective equipment and regular medical checkups.
Workers deserve clean air, fair treatment, and the peace of mind that comes from knowing that their government values their health as much as their labor.
None of these measures is extreme. They are essential for public health and for workers. The technology exists, and the data are clear. What’s missing from the picture is the political and administrative will to resist industry pressure and prioritize human health over corporate profits. Local efforts can make a significant difference in this matter. Labor unions, environmental justice advocates, and community groups have long fought for cleaner air and safer workplaces. State policy must continue to pressure OSHA and ensure California’s own agencies strengthen oversight and enforcement for plants and facilities that use EtO.
Currently, there is no viable alternative to this deadly chemical in its specific role. However, workers handling EtO, who perform essential jobs, shouldn’t sacrifice their health. They deserve clean air, fair treatment, and the peace of mind that comes from knowing that their government values their health as much as their labor.
OSHA must act now, because every day of delay means more workers inhaling a gas that is slowly poisoning and even killing them. Safety in the workplace is a fundamental human right, not a negotiable term in a contract. The people of the Bay Area, Los Angeles, and every other community living under the shadow of ethylene oxide deserve nothing less.
About the author
Jordan Cade is an attorney with the Environmental Litigation Group, P.C., a Birmingham, Alabama-based firm that provides legal services to victims exposed to toxic chemicals.