A Cobb State Court judge on Friday will consider whether the landlord of a medical device sterilization facility near Smyrna can be sued by hundreds of people who allege that the plant’s emissions of a known carcinogen caused them to get cancer.

The hearing marks a rare sign of movement in the ongoing legal and political campaign against Sterigenics, the facility’s operator.

The company had operated the facility since the 1970s with little fanfare — until 2019 when the company’s emissions were highlighted by a federal report on cancer risks.

Today, Sterigenics is battling legal challenges from nearby residents and workers. It faces an ongoing state review of its environmental permit and proposed federal rule-making that could place tighter controls on the release of ethylene oxide, the gas used to sterilize medical equipment.

The public disputes have stalled for much of the last year as court cases and regulatory reviews proceed.

And the company brought a federal lawsuit of its own against Cobb County, which is attempting to subject the facility to stricter permitting requirements. Meanwhile, Sterigenics has continued to operate under a federal consent order because of a nationwide shortage of protective equipment during the Coronavirus pandemic.

The stakes are high for the company and for the country’s medical supply chain.

As much as 50% of all sterile medical devices in the U.S. are treated with the gas, according to the federal government, which categorized the colorless gas as a cancer-causing agent in 2016. Since then, the company has installed new pollution controls that it says exceed state safety standards.

In November, close to 300 more people who say they developed cancer after living or working near the plant filed lawsuits against the company along with its landlord Prologis, a logistics real estate firm. Both companies have denied wrongdoing.

In response to the latest lawsuits, Sterigenics issued a statement to the AJC saying company officials sympathize with anyone battling cancer.

“However, our Atlanta facility operates safely as it sterilizes vital medical products, and we are confident that the facility’s operations have not caused any illness alleged in these lawsuits,” the statement says.

Oral arguments are scheduled Friday over whether Prologis can be held responsible for any harm done by the facility’s emissions, said Rob Hammers, one of the attorneys for the residents. The lawsuits allege that Prologis neglected its responsibility to maintain the roof and walls at the building at 2971 Olympic Industrial Drive.

The sterilization process involves applying ethylene oxide to equipment in a sealed chamber, where the air is scrubbed to eliminate gas emissions. The complaints against Prologis hinge on what are called “fugitive” emissions that remain after the scrubbing process.

Citing several roof leaks in the last decade, the suits allege Prologis enabled fugitive emissions present in the building to escape freely into the outside air.

Prologis argues that it is not liable for the activities of its tenant. The lease terms make Sterigenics responsible for complying with environmental requirements in its handling of hazardous materials, according to documents filed in court.

“With respect to the property at issue, Sterigenics has exclusive possession of the premises pursuant to a lease agreement and is solely responsible for its operations,” a company spokeswoman said in a statement to the AJC. “We have maintained the property as agreed upon under the lease.”

Hammers told the AJC that his clients are grouped into separate lawsuits by the type of cancer they have. The cases could proceed to trial in 2023, at the earliest.