Yesterday New York’s Appellate Division, First Department upheld the exclusion of an asbestos plaintiff’s experts, holding their “every exposure counts” theory scientifically unsound. While the case occurred in the context of friction products, its precedent may be useful in non-friction product cases as well.


In a trio of cases over the last decade, the New York Court of Appeals has repeatedly reinforced the principle that plaintiffs’ experts in toxic exposure cases must set forth that the plaintiff was exposed to sufficient levels of the at-issue toxin to cause the claimed illness. It is not enough, said the court in Parker v. Mobil Oil Corp.,[1] Cornell v. 360 West 51st Street Realty,LLC[2] and Sean R. v. BMW of North America[3] to rely solely on the fact that exposure to the toxin can cause the illness (general causation). Nor is it enough to attempt to quantify the exposures using vague generalities like “frequent” exposure to “excessive” amounts of the toxin. Rather, as the court in Cornell stated in 2014:

It is not enough for a plaintiff to show that a certain. . . agent sometimes causes the kind of harm that he or she is complaining of. At a minimum . . . there must be evidence from which the factfinder can conclude that the plaintiff was exposed to levels of that agent that are known to cause the kind of harm that the plaintiff claims to have suffered.”[4]

Though “precise quantification” or “an exact numerical value” are not required, there must be some “scientific expression” of exposure such as mathematical modeling based on work history or comparing the plaintiffs’ work history with those of subjects in peer-reviewed studies.[5]

The asbestos plaintiffs’ bar resisted the application of these principles in the asbestos context. The recent decision in Juni v. A.O. Smith Water Products Co. has decided the issue, for now.

The Juni case

In Juni, an auto mechanic performed maintenance and repair work on automobiles beginning in 1964 and died of mesothelioma in 2014. The plaintiff alleged that his illness was caused by inhalation of airborne asbestos fibers from the brakes, clutches and engine gaskets sold or distributed by the defendant. At trial, the plaintiff’s experts made no attempt to quantify exposures to the asbestos fibers from those components. One expert characterized his exposures as the “regular” use of asbestos-containing products. Another expert testified that exposure to one defendant’s product was part of “cumulative exposures.” The court granted the manufacturer’s post-trial motion to strike the plaintiff’s expert testimony, set aside the plaintiff’s jury verdict and dismissed the case.

On appeal, the First Department affirmed the trial court’s holding that there was no valid line of reasoning that would allow a jury to find causation based on the Juni experts’ “cumulative exposure” theory “that even a single exposure to asbestos can be treated as contributing to an asbestos-related disease.” That theory “is irreconcilable with the rule requiring at least some quantification or means of asserting the amount, duration, and frequency of exposure to determine whether exposure was sufficient to be found a contributing cause of the disease.”

The court explicitly rejected the argument by the one dissenting judge who, echoing the asbestos plaintiffs’ bar, suggested that asbestos plaintiffs should be held to a different standard than plaintiffs alleging other toxic exposures, e.g., benzene. It is not insurmountable, the court held, for an asbestos plaintiff’s expert to employ methods of estimating exposure as suggested in Parker and the other cases.


The practical effect of Juni to the full range of asbestos cases remains to be seen. It certainly applies in cases involving friction products such as brakes, clutches and engine gaskets. As pointed out by the Juni court, the scientific evidence in friction cases is not favorable to plaintiffs. Twenty-one of 22 epidemiological studies involving mechanics working on friction products found no increased incidence of mesothelioma; 99% of the debris from brake wear is not comprised of asbestos fibers. But can it apply outside the context of friction products?

The court, almost as if to assuage those who fret that asbestos plaintiffs will face “insurmountable” obstacles to proving causation, pointed out that Juni’s experts had testified in other cases about non-friction products and did provide sufficient scientific support by citing specific studies quantifying the amount of asbestos fibers released from those products.

But Juni could still apply in non-friction product asbestos cases, even where at-issue products are known to release asbestos fibers and, with sufficient exposure, contribute to mesothelioma causation. Where a plaintiff, for example, had de minimis exposures to such products, say from a sporadic or short work history, Juni’s rejection of “every exposure counts” theory should bolster defense of such cases.

Of course, all depends on the Court of Appeals where Juni may be expected to go next.