Back in August 2022 Cal/OSHA opened an investigation, and later issued 18 citations, including six citations for willful-serious violations, to Parter Medical Products, Inc. in Carson California for failing to protect its employees from overexposure to ethylene oxide (EtO), a toxic chemical. The proposed penalties totaled $838,800. It’s inspection showed “this was not an isolated incident of chemical overexposure to workers. Parter Medical Products, Inc. dba Parter Sterilization Services was founded in 1984, and uses ethylene oxide gas to sterilize medical devices.

The Carson City Council unanimously voted in early 2022 to request air monitors be placed in various locations of the city to monitor air quality. South Coast AQMD was further investigating EtO emissions in the nearby residential communities and the agency was working with the City of Carson to identify additional locations to collect 24-hour samples in the nearest community and school. So far, data from residential monitors show EtO levels to be within typical background levels.

On March 14, 2024 the U.S. Environmental Protection Agency announced a rule that will reduce lifetime cancer risks for people living near commercial sterilization facilities across the country. The final amendments to the air toxics standards for ethylene oxide commercial sterilization facilities put in place the strongest measures in U.S. history to reduce emissions of EtO, one of the most potent cancer-causing chemicals. Through the installation of proven and achievable air pollution controls, commercial sterilizers will reduce emissions by more than 90%.

However, it appears that now in 2025, Parter continues to be under close scrutiny since the Los Angeles County District Attorney Nathan J. Hochman announced this week that members of his Bureau of Investigation executed a search warrant as part of an ongoing criminal investigation into allegations that Parter Medical Products, Inc., doing business as Parter Sterilization Services, failed to protect its employees from prolonged exposure to ethylene oxide, a known toxic chemical.

“No employer should risk the safety of their workers by exposing them to toxic substances and then turn a blind eye,” District Attorney Hochman said. “Ethylene oxide can silently poison people over time — causing cancer, damaging organs, and cutting lives short. We remain steadfast in our commitment to follow the evidence wherever it leads and will not hesitate to hold accountable any individual or organization that puts profits over public health.”

More than 20 members of the District Attorney’s Bureau of Investigation, in coordination with the Los Angeles County Fire Department and the California Department of Toxic Substances Control, executed the search warrant on July 17 at Parter Medical Products Inc., in the city of Carson.

Ethylene oxide is a hazardous gas linked to cancer, reproductive harm, and neurological damage. It is colorless and its odor is undetectable to the human nose until it reaches harmful concentrations. Despite being aware that some employees were exposed to elevated levels of the chemical, the company is accused of failing to take adequate steps to mitigate the danger.

The matter is being investigated by Assistant Head Deputy Daniel Wright of Environmental Crimes and the District Attorney’s Bureau of Investigation. Anyone with information related to this matter may call AHD Wright at (213) 257-3001.