By Alfredo Santana
Contributing Writer
VERNON — Sterigenics U.S., an industrial plant that released high quantities of a carcinogenic chemical used to sterilize medical equipment, will remain open amid a probe conducted by the South Coast Air Quality Management District to identify the leak and its causes.
The decision made by South Coast AQMD Executive Director Wayne Nastri comes on the heels of a letter written by county Supervisor Janice Hahn asking the regulatory agency to shut down operations at Sterigenics that contributed to high emissions of ethylene oxide.
In her letter, Hahn said that Maywood residents live 500 feet away from two Sterigenics plants, a community that has long been punished by lead contamination from the shuttered Exide Technologies battery plant, in addition to metal pollution from a magnesium chemical fire.
“I am gravely concerned that two Sterigenics facilities continue to operate next to people working, living and going to school nearby,” Hahn said in the letter.
The nearest school in Maywood from the Sterigenics locations is about 1,700 feet away.
The supervisor’s request followed an AQMD notice of violation issued against Sterigenics on May 5 for its failure to maintain its equipment in good operation condition.
Following a March 2022 reconsideration from the Environmental Protection Agency of the potential toxicity from ethylene oxide, or EtO, the AQMD conducted impromptu air quality tests outside the facilities at 4900 Gifford Ave., detecting elevated levels of the flammable gas.
The results triggered further investigations into air monitoring, resulting in violations including equipment not listed in the permits and storage tanks with lax maintenance.
“Facilities are required to properly maintain their air pollution control equipment and to comply with all permit conditions in order to avoid excess emissions,” Nastri said in a statement. “We will continue to conduct air sampling in the area and near the community, and we will do everything in our power to reduce emissions from the facility.”
The agency said that preliminary data showed EtO levels in the community to be within background levels and below dangerous levels permitted by the California Office of Environmental Health Hazard Assessment.
Air samples were taken at three community locations.
As part of its ongoing investigation, the AQMD announced that two air monitors were installed outside the Sterigenics’ premises to gauge air quality every 24 hours and said it is evaluating risks of cancer among off-site workers and validating it with the state Office of Environmental Health Hazard Assessment.
On May 22, an AQMD van was parked on the curbside steps away from the main entrance of the Sterigenics offices.
“The monitoring data collected to date has confirmed the initial elevated readings of EtO surrounding the Sterigenics facilities pose an elevated cancer risk for nearby off-site workers,” Nastri told Hahn in a letter he sent May 19.
Nastri said that his agency has not logged any public complaints in the last five years concerning elevated toxic emissions at the two Sterigenics locations in Vernon.
“If any air quality complaints for these facilities are received, South Coast AQMD inspectors will respond promply,” Nastri said.
Following the ethylene oxide release, the agency made a series of notifications to the county health officer, the Board of Supervisors, and to the city of Vernon health director as directed by Proposition 65, a law that requires businesses to warn state residents about significant exposures to chemicals that cause cancer, birth defects or reproductive harms.
Proposition 65 is also known as the Safe Drinking Water and Toxic Enforcement Act of 1986.
The EtO fumes also prompted the air quality agency to notify the California Division of Occupational Safety and Health of the hazardous chemical that may have exposed staff at Sterigenics and neighboring facilities.
As part of the onsite investigation, the air quality agency indicated a series of measures that include identification and mitigation of sources that contributed to the elevated emissions, and testing with focus on a wet scrubber.
Another legal action the agency can carry is the issuance of an order of abatement, to require the facility to stop incurring violations of air quality rules and regulations, or cease its operations.
“South Coast AQMD is committed to doing everything within our authority, and working closely with our partners agencies, to protect the health and safety of community members and workers who may be impacted by Sterigenics,” Nastri said.
State Sen. Lena Gonzalez, D-Long Beach, who represents Maywood, and Vernon City Administrator Carlos R. Fandino also received similar letters.
Hahn said she is not satisfied with the AQMD response.
“They say they are working with this company to lower the emissions of ethylene oxide, but I think they need to cease operations until they can prove they can operate safely and not put workers and local residents at risk,” the supervisor said.
In 2017, Sotera Health LLC became the umbrella parent company of Sterigenics International, adding it to Nelson Labs and Nordion.
Sotera Health Co. trades on the technology-ladden Nasdaq stock exchange, with shares valued at $20.35 on May 24 and a trading volume of 344,175 units.
On its website, Sterigenics indicates that ethylene oxide sterilization occurs when gas molecules react with and destroy microbial DNA, and that the process depends on its ability to diffuse through a product being packaged.
In a video posted on its website, the company indicates it helps sterilize material used in the manufacture of COVID-19 vaccine containers and syringes.
Colorless and flammable, EtO can cause lymphoid and breast cancer if exposed for long periods of time, but short-term exposures can provoke headaches, nausea, diarrhea, eye and skin burns and problems on reproduction.
EtO is also used in the production of antifreeze, textiles, solvents, detergents and adhesives.
Sterigenics spokesperson Kristin Gibbs said in an email the company is committed to its mission of safeguarding global health, and is confident in the safety of its employees and communities they operate.
She said the company is implementing additional, voluntary enhancements at the facilities to further reduce emissions, in addition to cooperating with the AQMD to address the concerns raised at the Vernon plants.
“The Vernon facilities play a critical role in safeguarding public health by providing FDA-mandated sterilizations for over 45 million essential medical devices and supplies each year, including surgical kits, catheters, cardiac implants, stents, IV sets and more, that are supplied to nearly 100 healthcare manufacturers, including dozens in the Los Angeles area, as well as local hospitals,” Gibbs said.
