Colorado Ethylene Oxide Lawsuit: Defense Verdict and $5.18M Order

The Colorado ethylene oxide lawsuit against Terumo Blood and Cell Technologies has, so far, gone badly for the residents who sued. In March 2025, a Jefferson County jury returned a complete defense verdict in the first case to reach trial, and in September 2025 the judge ordered the four losing plaintiffs to pay Terumo $5.18 million in costs. A related class action was dismissed on appeal in October 2025. Hundreds of individual cancer cases remain pending, but the ground has shifted sharply in the company’s favor.1CMBG3. Ethylene Oxide Verdict2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose

Who Is Being Sued and Why

Terumo BCT has operated a medical device sterilization facility in Lakewood, Colorado, for roughly 60 years. The plant uses ethylene oxide to sterilize catheters, resuscitation bags, anesthesia masks, and other devices that can’t withstand heat or moisture. It sits in a residential area, near homes, schools, and day care centers.2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose3Terumo BCT. EtO FAQ

Ethylene oxide is classified as a known human carcinogen by both the International Agency for Research on Cancer and the National Toxicology Program. The chemical damages DNA, which is what makes it useful as a sterilizer and what makes it dangerous. Lymphoma, leukemia, and breast cancer are the cancers most commonly linked to occupational exposure in the scientific literature.4OSHA. Ethylene Oxide Hazards5National Cancer Institute. Ethylene Oxide

In 2018, the EPA identified the Lakewood plant as one of 26 U.S. facilities where ethylene oxide use could pose elevated cancer risks. Updated modeling in 2022 estimated that residents closest to the facility faced a lifetime cancer risk of 600 in a million, with about 9,450 people living within a mile, including 1,900 children.6CBS News Colorado. Thousands of Lakewood Residents Have Heightened Cancer Risk Hundreds of Jefferson County residents sued, represented primarily by Edelson PC and Zaner Harden Law. They alleged Terumo and its predecessors had known since at least 1994 that emissions would have a toxic effect on the surrounding community.7Colorado Sun. Did Toxins From a Colorado Manufacturer Cost a Young Man His Leg

What the First Trial Decided

The first case to reach a jury was Isaacks et al. v. Terumo BCT Sterilization Services Inc. et al., tried over six weeks in Jefferson County District Court in early 2025. It was the first multi-plaintiff ethylene oxide case tried in the country and only the fifth EtO trial of any kind since this wave of litigation began in 2018.8King & Spalding. King & Spalding Secures Complete Defense Verdict for Terumo in Bellwether Ethylene Oxide Case

Four women were the plaintiffs. Two alleged breast cancer after 23 and 35 years of exposure. One alleged multiple myeloma; one alleged Hodgkin’s lymphoma. They sought more than $217 million for physical impairment and $7.5 million in medical expenses, plus punitive damages, with their attorneys framing the total ask at $444 million.1CMBG3. Ethylene Oxide Verdict2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose

Terumo argued it had managed ethylene oxide in compliance with EPA and Colorado law, including filtration systems that went beyond regulatory requirements. It also pointed to a Colorado Department of Public Health and Environment epidemiological study that found no statistically significant increase in EtO-linked cancers in the ZIP codes around the facility, arguing that the actual cancer data did not match the EPA’s risk modeling.2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose9Terumo BCT. Status Report – Terumo Lakewood CO

On March 14, 2025, after roughly one day of deliberations, the six-person jury returned a complete defense verdict, finding Terumo not negligent in its handling of emissions. Because the case turned on the negligence question, the jury never reached causation or damages.1CMBG3. Ethylene Oxide Verdict

The $5.18 Million Cost Order

In May 2025, the plaintiffs’ attorneys moved for a new trial, alleging Terumo had engaged in “a systematic pattern of misconduct” by attacking plaintiffs for hiring lawyers instead of addressing whether emissions caused harm, and that these tactics “inflamed the jury.” Terumo’s team had subpoenaed Meta for records related to the plaintiff firms’ digital advertising, which plaintiffs fought as irrelevant. The motion was denied.10Rocky Mountain Voice. Colorado Judge Orders Losing Plaintiffs to Pay Terumo $5.2 Million11Law360. Law Firm’s Ads Irrelevant to Toxic Tort Case, Plaintiffs Say2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose

Then, on September 22, 2025, Jefferson County District Judge Andrew Poland ordered the four plaintiffs to pay Terumo $5,180,000 in legal costs. Nearly $4.2 million of that was expert witness fees alone. Judge Poland relied on Colorado’s standard that the prevailing party is entitled to reimbursement of reasonable costs.2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose

Plaintiffs’ attorney Kurt Zaner called the reimbursement request “merely an attempt to discourage other plaintiffs from pursuing their cases” and said the plaintiffs will appeal. Terumo characterized the order as a “routine result of the jury’s verdict” and said it expected the law firms that recruited plaintiffs, rather than the individual plaintiffs themselves, to cover the costs.10Rocky Mountain Voice. Colorado Judge Orders Losing Plaintiffs to Pay Terumo $5.2 Million2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose

Why the Class Action Was Dismissed

A separate case tried to open a route for residents who had been exposed but not yet diagnosed. In Smith v. Terumo BCT, Inc., a Lakewood resident filed a putative class action seeking medical monitoring for people exposed to the plant’s emissions. On October 30, 2025, the Colorado Court of Appeals affirmed the dismissal of that suit.12Colorado Judicial Branch. Smith v. Terumo BCT, Inc., No. 24CA1393

The court held that a plaintiff cannot establish standing based only on allegations that a defendant’s conduct increased the risk of future illness. Mere exposure to a toxic chemical, without an accompanying adverse physical impact, is not enough to support a toxic tort claim in Colorado. The court also held that no Colorado state court has recognized medical monitoring as a standalone cause of action, meaning plaintiffs cannot recover the cost of diagnostic testing without first showing a present physical injury.12Colorado Judicial Branch. Smith v. Terumo BCT, Inc., No. 24CA139313Law360. Injury Risk Can’t Support Toxic Tort Claims, Colo. Court Finds

The practical effect: in Colorado, only residents already diagnosed with a qualifying cancer have a viable claim against Terumo. Exposure alone, no matter how prolonged, will not get a case past a motion to dismiss.

Where the Remaining Cases Stand

Hundreds of individual claims are still pending against Terumo in Colorado, and all involve plaintiffs who allege they have already been diagnosed with cancer. Nearly 25 additional cases were filed while the bellwether trial was still underway. Plaintiffs’ counsel has said further trials are scheduled.1CMBG3. Ethylene Oxide Verdict2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose

The trend since the verdict has not been encouraging for those plaintiffs. In January 2026, one of two plaintiffs set for the next trial against Terumo stipulated to dismiss his case before the trial began.14Law360. Terumo Plaintiff Settles, Drops Cancer Case Before Trial The threat of another multi-million-dollar cost order hanging over the bellwether plaintiffs is likely to influence how aggressively the remaining cases are litigated and how many settle before verdict.

Why the EPA Numbers Didn’t Win the Case

Reading news coverage of the EPA’s cancer-risk estimates, the plaintiffs’ loss can look surprising. The gap that mattered at trial was between two different kinds of evidence. The EPA’s figures were risk projections, modeling what elevated exposure could do over a lifetime. The Colorado Department of Public Health and Environment ran air monitoring and an epidemiological study of actual cancer cases in the ZIP codes around the plant, and found no statistically significant elevation in the cancers associated with ethylene oxide inhalation.9Terumo BCT. Status Report – Terumo Lakewood CO

Terumo pointed the jury to the state study and to the fact that it operated within its EPA and Colorado permits, along with voluntary emission controls the company said reduced EtO releases by 50 to 75 percent starting in 2018 and later a $22 million system it says destroys more than 99 percent of the ethylene oxide used at the plant.2Colorado Sun. Terumo Court Costs $5.2 Million in Plaintiffs Lose9Terumo BCT. Status Report – Terumo Lakewood CO3Terumo BCT. EtO FAQ The jury never reached whether ethylene oxide caused any specific plaintiff’s cancer. It found Terumo not negligent in how it handled emissions, and that ended the case.

How Colorado Compares to Ethylene Oxide Cases Elsewhere

Ethylene oxide litigation has produced very different outcomes in different states, mostly involving Sterigenics rather than Terumo:

The Colorado result fits a pattern of recent defense wins involving facilities that operated within their regulatory permits. The Illinois cases that produced the largest plaintiff outcomes involved a Sterigenics plant that ultimately closed in 2019, with a factual record different in key respects from Terumo’s Lakewood operations. For Colorado plaintiffs still in the queue, the combination of the Isaacks defense verdict, the $5.18 million cost order, and the Smith appellate ruling has narrowed the path to recovery considerably, even before their cases reach a jury.