August 11, 2009
By: David K. Jaffe
Many people suffer product-related injuries because they are allergic to ingredients in the products they use. Where the product or an ingredient in the product would not cause injury to most normal people, the manufacturer, middleman, or retailer being sued may raise as a defense that the user's peculiar susceptibility to the product or one of its ingredients was the cause of the user's injury, and that the product itself cannot properly be characterized as having caused the injury. The success of this defense may depend on the circumstances surrounding the product's manufacturing, marketing, and use.
Strict Liability in Tort
The Rule of the Restatement (Second) of Torts, § 402A governing strict liability to allergic users is phrased in terms of a duty to warn. Comment j to § 402A states in pertinent part:
The seller may reasonably assume that those with common allergies, as for example to eggs or strawberries, will be aware of them, and he is not required to warn against them. Where, however, the product contains an ingredient to which a substantial number of the population are allergic, and the ingredient is one whose danger is not generally known, or if known is one which the consumer would reasonably not expect to find in the product, the seller is required to give warnings against it, if he has knowledge, or by the application of reasonable, developed human skill and foresight should have knowledge, of the presence of the ingredient and the danger.
If the seller has no knowledge of the kind specified in this comment, then there apparently would be no liability, even to the substantial number of allergic persons who have not been warned. Analytically, in requiring knowledge or unreasonable failure to have knowledge, § 402A is not as generous to plaintiffs as some warranty cases which do not require knowledge on the part of the manufacturer if the product causes harm to a specified group of persons.
In Oakes v. Geigy Agricultural Chemicals, the rule of § 402A, requiring warning only when the manufacturer knows or should know of a special danger, was applied to deny liability where the use of a weed killer by the plaintiff resulted in a severe systemic skin condition due to an allergic reaction to one of the weed killer's ingredients. The Oakes court noted that the rationale for the doctrine of strict liability is to place the burden of injuries caused by defective products on the producers of those products, particularly in instances in which a defenseless individual is the victim of injury. It further noted that the same rationale would apply to the marketing of a product which contains an ingredient which the manufacturer knows or should know by the application of reasonable, developed skill and foresight, is dangerous. But the Oakes court felt that to extend an obligation to warn the user of unknown and unknowable allergies, sensitivities and idiosyncrasies would be for the courts to recast the manufacturer in the role of insurer beyond any reasonable application of the rationale for the doctrine of strict liability in tort.
The trend of decisions has broadened the narrowly drawn scope of § 402A in allergic reaction cases. For example, although the Restatement rule requires a warning only "where a substantial number of the population are allergic," the Connecticut Supreme Court, in Tomer v. American Home Products Corp., held that strict liability could be a basis of recovery against a seller whose product produces allergic reactions in only a small number of users. Tomer involved a hypersensitive reaction to anesthesia. There was evidence that the plaintiff's decedent died from liver damage resulting from the administration of the defendant's anesthesia product during surgery. The trial court entered judgment on a jury verdict in favor of the defendant manufacturer and defendant doctors who were involved in the operation. On appeal, the Connecticut Supreme Court held that the trial court had erred in instructing the jury that the manufacturer had a duty to warn users of substances or ingredients which it knew or reasonably should have known had a tendency to affect injuriously "an appreciable number of people." The Court held that if a manufacturer knows or should know that a product may cause serious injury to others, but does not warn of the potentially injurious effects through negligence or through a decision to be silent out of concern that information would decrease sales of the product, the seller cannot be insulated from the imposition of strict liability in tort just because an appreciable number of users would not be affected. The Court noted, however, that if the number of allergic individuals is very small, that fact would be relevant to the issue of the manufacturer's knowledge.
As a general matter, however, there is still wide acceptance of the notion that strict liability for allergic reactions to products should not be made available to plaintiffs who are unable to show that more than a few users of the product were liable to be injured or that the manufacturer was aware or should have been aware of that significant risk.
 Oakes v. Geigy Agricultural Chemicals, 272 Cal. App. 2d 645, 77 Cal. Rpt. 709 (1969). See also Thomas v. Gillette Co., 230 So. 2d 870 (La. Ct. App. 1970). The plaintiff sustained injuries from an acute allergic reaction to a hair relaxer product. The court held no liability could be imposed since no defects were found in the product. In the absence of any defects, no warnings would be required.
 Restatement (Second) of Torts, § 402A cmt. j.
 Tomer v. American Home Products Corp.,170 Conn. 681, 368 A.2d 35 (1976).
 See, e.g., Gordon v. Proctor & Gamble Distrib. Co., 789 F. Supp. 1384 (W.D. Ky. 1992).