Products Liability Law Daily Wrap Up, CAUSATION—CHEMICAL PRODUCTS—Haw. Sup. Ct.: Dow and Del Monte face trial after Hawaii Supreme Court adopts new toxic-exposure causation test, (Sep 24, 2026)

By Pankhuri Bhatnagar, B.A. LL.B.

Evidence that a plantation worker may have been exposed to a pesticide, along with the worker’s expert evidence on specific causation, created genuine disputes that precluded summary judgment.

In an action brought against a pesticide manufacturer and a farm owner by banana plantation workers who allegedly sustained injuries due to exposure to a pesticide, the Hawaii Supreme Court affirmed an intermediate appellate court’s reversal of summary judgment for the companies. The court adopted a new causation framework for toxic-tort cases requiring proof of exposure, general causation, and specific causation. It also held that expert testimony is required to establish causation in toxic-tort cases, but declined to impose a rigid dose or exposure threshold. Circumstantial evidence may establish exposure if it permits reasonable inferences rather than speculation, and no particular form of words is required from an expert addressing causation (Patrickson v. Dow Chemical Co., No. SCWC-22-0000687 (Haw. Sup. Ct. Sept. 21, 2026)).

Background. From 1971 to 1973, a man worked as a quality fruit inspector for Bandeco, a Costa Rican banana company owned by Del Monte Fresh Produce N.A., Inc. He rotated among 18 farms, worked up to seven days a week, occasionally entered fields with farm administrators, and sometimes slept in warehouses where agricultural chemicals were stored. He never applied, handled, or observed the application of dibromochloropropane (DBCP), a pesticide manufactured by Dow Chemical Company. Bandeco applied a 50-percent diluted DBCP solution to approximately 1,400 to 1,800 plants per acre during two application cycles each year. The man and his wife later experienced infertility and repeated miscarriages, prompting them to file suit against Del Monte, Dow, and other entities. The worker’s operative complaint alleged negligence, conspiracy, and intentional torts based on DBCP exposure. He died in 2023 while the litigation was pending.

Prior proceedings. The claimants’ toxicologist opined that “even short-term exposures to relatively low[] concentrations of DBCP in the air could be toxic to the male reproductive system” and that the man’s exposure most likely occurred through inhalation and potential dermal contact while he worked around the plantations and slept near stored chemicals. The expert relied partly on an epidemiological study involving agricultural workers exposed to DBCP, which found increased rates of miscarriages among their wives. A state trial court granted Dow’s motions for summary judgment and in limine and Del Monte’s joinders, finding that the worker failed to establish legal causation and that his expert’s opinions lacked an evidentiary basis. The Intermediate Court of Appeals (ICA) vacated the trial court’s orders, holding that the man’s deposition testimony raised genuine issues regarding his alleged exposure and the resulting adverse health effects. This court granted certiorari.

Exposure and causation. Dow argued that summary judgment was warranted because the man never applied DBCP, never saw it being applied, could not identify a DBCP container, and did not work directly in the application areas. It also challenged the expert’s reliance on the epidemiological study because the study participants had direct DBCP contact. The state supreme court rejected both the traditional substantial-factor approach and the frequency, regularity, and proximity test urged by Dow and Del Monte. The latter test is “merely an articulation of what constitutes a substantial factor for purposes of determining proximate cause in an occupational exposure setting.” Menne v. Celotex Corp., 861 F.2d 1453, 1464 (10th Cir. 1988). In Smith v. Cutter Biological, Inc., 72 Haw. 416, 823 P.2d 717 (1991), the court had recognized that traditional causation rules were inadequate for mass toxic-tort cases.

The court now adopted comment g to section 26 of the Restatement (Third) of Torts: Physical and Emotional Harm, but reordered its framework to require, first, exposure to the toxic agent; second, general causation, meaning the substance is capable of causing the claimed disease; and third, specific causation, meaning exposure to that substance caused the particular disease. The court also rejected a categorical requirement that exposure levels or dosage be quantified. Although a claimant must ultimately prove but-for causation by a preponderance of the evidence, circumstantial evidence may establish exposure and specific causation. Any such evidence must support reasonable inferences rather than speculation. Trial courts must also perform their gatekeeping function to ensure expert testimony is relevant and reliable.

Expert testimony. The state high court held that the toxicologist’s opinions satisfied Hawaii’s expert-evidence requirements. Under State v. Kim, 64 Haw. 598, 645 P.2d 1330 (1982), expert testimony must rest on a sound factual foundation and a reliable analytical method. Here, the expert relied on the worker’s deposition testimony and the epidemiological study, which together provided circumstantial evidence supporting both exposure and specific causation. The trial court therefore abused its discretion by excluding the testimony. Further, pursuant to Dzurik v. Tamura, 44 Haw. 327, 359 P.2d 164 (1960), an expert need not use a particular formulation or state with absolute certainty that the toxic substance caused the injury. Whether the evidence establishes causation remains for the factfinder.

Applying the new framework, the worker’s testimony that he spent substantial time across the farms, frequently entered fields, worked long hours, and slept near stored chemicals, together with Del Monte’s admissions concerning DBCP application, created a genuine dispute over exposure. The expert’s reliance on the epidemiological study also supplied a sufficient scientific basis for specific causation, i.e., that the worker’s DBCP exposure more likely than not caused his infertility and his wife’s miscarriages. The court declined to impose a categorical requirement that epidemiological evidence demonstrate a doubling of risk, although the study here showed that DBCP exposure was associated with more than twice the rate of spontaneous abortions among the relevant workers’ wives. This court therefore affirmed the ICA’s judgment and remanded for further proceedings.

The case is No. SCWC-22-0000687.

Judge: McKenna, S.

Attorneys: Keith M. Kiuchi (Keith M. Kiuchi, ALC) and Scott M. Hendler (Hendler Flores Law, PLLC) for Gerardo Dennis Patrickson, Benigno Torres Hernandez, Fernando Jimenez Arias, Alirio Manuel Mendez and Carlos Humberto Rivera. Steven L. Goto (Chong, Nishimoto, Sia, Nakamura & Goya, LLLP) and Michael L. Brem (Schirrmeister Diaz-Arrastia Brem LLP) for Dow Chemical Co. David W.H. Chee (David W.H. Chee, Attorney at Law) for Del Monte Fresh Produce N.A., Inc.

Companies: Dow Chemical Co.; Del Monte Fresh Produce N.A., Inc.

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