TL;DR

• Dow Chemical made the pesticide DBCP, which a Costa Rican banana subsidiary of Del Monte injected into the soil around its plants by the thousands of gallons a year in the early 1970s.
• Fernando Jimenez Arias, a quality inspector who rotated through eighteen of the company’s farms, says he was never told what the chemical was or that it was dangerous, and never applied it himself.
• He and his wife tried for years to have children; she had three miscarriages between 1977 and 1983, and doctors never told her why.
• A trial judge threw the case out, ruling there was no evidence Arias was ever exposed to DBCP and barring his toxicologist from testifying.
• The Hawai‘i Supreme Court disagreed, ruling on September 21, 2026 that circumstantial evidence, including Del Monte’s own admissions about how much DBCP it used, is enough to send the case to a jury.
• The court used the case to adopt a new statewide test for proving cause in toxic exposure lawsuits, rejecting a stricter dosage-based standard the companies wanted.
• The case, filed roughly two decades ago, now returns to trial in circuit court. Arias died in 2023, while the lawsuit was still pending.

The ruling doesn’t decide who’s responsible for what happened to Arias and his family. It decides that a jury, not a judge on paperwork, gets to hear the evidence and make that call.

Transparency Notice

This article is based on the Hawai‘i Supreme Court’s published opinion in Patrickson v. Dow Chemical Co., SCWC-22-0000687, issued September 21, 2026. The opinion draws on deposition testimony, Del Monte’s discovery admissions, a 1980 medical study, and the expert report of toxicologist Michael DiBartolomeis.

Nothing in the underlying lawsuit has been finally decided. The Supreme Court’s ruling reinstates Arias’s claims and sends them back for trial; it does not find Dow or Del Monte liable for anything. Statements attributed to Del Monte are drawn from its own sworn interrogatory answers in the case record. Where this article describes what Arias experienced or believed, it is relying on his deposition testimony as summarized by the court.

The Facts

Fernando Jimenez Arias worked as a quality fruit inspector for Bandeco, a Costa Rican banana company owned by Del Monte, from 1971 to 1973. His job rotated him weekly through eighteen farms, fifteen of them owned outright by Bandeco. He worked up to seven days a week with little to no vacation, sometimes staying on a farm for a week at a stretch when the volume of bananas demanded it.

During those years, Bandeco was treating its banana plants with dibromochloropropane, or DBCP, a nematicide manufactured by Dow Chemical. According to Del Monte’s own answers to written discovery questions, workers injected a 50 percent diluted solution of DBCP directly into the soil around each plant, six to eight injections per plant, across roughly 1,400 to 1,800 plants per acre, in two application cycles a year lasting about two months apiece. By the company’s own math, that comes out to between roughly 3.6 and 7.7 gallons of DBCP per cultivated acre every year.

Arias says he never applied the chemical, never watched anyone apply it, and couldn’t identify a container of it. What he does remember: walking the fields with farm administrators after the day’s cutting was done, and, when rain or a backlog of fruit kept him on-site overnight, sleeping in warehouses on or near sacks of farm chemicals whose contents he was never told.

What DBCP Was, and Why It Mattered

DBCP is a chemical used to kill microscopic worms, called nematodes, that damage plant roots. It was widely applied on banana and pineapple plantations across Central America in the 1960s and 1970s. The court’s opinion doesn’t detail when Dow or plantation operators first learned of the chemical’s risks to human reproduction; that history is not part of the record in this appeal. What the opinion does document is what medical researchers found among the men who worked directly with it, and what happened to Arias’s own attempts to start a family.

Arias married his wife, Vilma Julieta Graham Mastiel, in 1968. The couple tried unsuccessfully to have children until Mastiel’s first pregnancy in 1971, the same year Arias started at Bandeco. That child died in infancy of an unrelated illness. The couple went on to have a biological daughter in 1975 and adopted a second. But between 1977 and 1983, Mastiel had three more pregnancies, each ending in miscarriage within a few months of conception. She never used birth control. Her doctors never explained why the pregnancies kept failing.

The Evidence at the Center of the Case

Plaintiffs’ toxicologist, Michael DiBartolomeis, reviewed Arias’s work history and a body of medical literature on DBCP and concluded, to what he called a reasonable degree of scientific probability, that Arias’s likely exposure to the chemical, through inhalation and skin contact in the fields, packing facilities, and chemical warehouses, was the most plausible explanation for his infertility and his wife’s miscarriages.

DiBartolomeis leaned heavily on a 1980 study of Israeli banana workers by researchers Martin Kharrazi, Gad Potashnik, and John Goldsmith. The study interviewed 62 men, 56 of whom had direct contact with DBCP, and tracked the outcomes of 197 pregnancies among their wives. Pregnancies conceived before the husbands’ DBCP exposure ended in miscarriage 6.6 percent of the time; pregnancies conceived after exposure began ended in miscarriage 19.8 percent of the time. The study’s own authors cautioned that this kind of study can show an association without proving that DBCP caused it, language the court’s opinion quotes directly.

The Trial Court Threw the Case Out

Dow moved for summary judgment on Arias’s claims, arguing there was no evidence he had ever come into contact with DBCP at all, only that he had worked on farms where it was used. Del Monte joined the motion. Dow also moved to exclude DiBartolomeis’s testimony entirely, arguing his opinions were speculative because he assumed Arias spent more time in the fields than his own testimony supported.

The circuit court agreed with Dow on both counts. It excluded DiBartolomeis’s report, finding it rested on no evidence of actual exposure, and then granted summary judgment, ruling there was “no substantial evidence” that Dow’s conduct had caused Arias harm. That combination, no expert testimony and no other evidence of exposure, ended his case before it reached a jury.

What the Supreme Court Actually Decided

The Intermediate Court of Appeals reversed course first, ruling in September 2025 that Arias’s own deposition testimony raised genuine factual disputes about his exposure. Dow and Del Monte then asked the Hawai‘i Supreme Court to overturn that reversal, arguing the ICA had applied the wrong legal standard and that dosage evidence should be required to prove exposure in toxic tort cases.

The Supreme Court sided with the ICA on September 21, 2026, and went further, using the case to settle a question Hawai‘i courts had never squarely answered: what a plaintiff must show to prove a toxic chemical caused their injury.

The court rejected the “frequency, regularity, and proximity” test that Dow and Del Monte wanted, the standard used in many asbestos cases, on the grounds that it’s just another version of a “substantial factor” test the court had already found unworkable for mass toxic exposure cases back in 1991. Instead, the court adopted a three-part framework drawn from the Restatement (Third) of Torts: a plaintiff must show they were exposed to the chemical, that the chemical is capable of causing the type of harm alleged (general causation), and that it did in fact cause their specific injury (specific causation).

Importantly, the court declined to require plaintiffs to quantify their exact dose of exposure, something Dow had pushed for and which, if adopted, would have been difficult or impossible for workers like Arias to satisfy decades after the fact. Circumstantial evidence of exposure, the court held, combined with reliable expert testimony connecting that exposure to the alleged injury, is enough to get a case in front of a jury.

Applying that framework to Arias, the court found that his seven-day work weeks, his time walking fields with farm administrators, his overnight stays in chemical warehouses, and Del Monte’s own admissions about how heavily DBCP was appli