## Facts

- Inga Kaempfe used “Etiquet” spray deodorant manufactured by Lehn & Fink Products Corp.
- The deodorant contained aluminum sulfate, a common antiperspirant ingredient used in most comparable deodorants.
- After use, Kaempfe developed severe underarm dermatitis (burning, blistering, itching) that persisted for a time but caused no permanent injury.
- Kaempfe had no prior history of similar allergic reactions or skin conditions.
- Kaempfe’s medical expert attributed the condition to an allergic reaction to aluminum sulfate and testified the product was safe for most people.
- The manufacturer showed it sold about 600,000 units and received only four complaints of adverse reactions (about 1 in 150,000).
- Kaempfe sued for negligent failure to warn consumers of possible allergic reactions to aluminum sulfate.
- A jury found for Kaempfe and awarded damages; the manufacturer appealed.

## Issues

1. Whether a manufacturer of a widely used consumer product that is generally safe has a duty to warn of possible allergic or idiosyncratic reactions affecting only a minute fraction of users.
2. Whether the evidence supported a finding that the manufacturer was negligent for failing to provide a general warning about such rare reactions.

## Decision

- The Appellate Division reversed the judgment for Kaempfe and set aside the jury’s liability finding.
- The court held that, on this record, Lehn & Fink was not negligent in failing to warn generally of the possibility of an allergic reaction to aluminum sulfate.
- The court treated the extremely low complaint rate, the ingredient’s widespread use, and the product’s general safety as defeating the asserted duty to warn.
- The Court of Appeals later affirmed the disposition without extended discussion.

## Legal Principles

- A manufacturer is not required to warn of every remote possibility of harm from a consumer product.
- No general duty to warn ordinarily arises for allergic or idiosyncratic reactions where the product is safe for most users and only a minute fraction is susceptible.
- In assessing a failure-to-warn negligence claim, courts consider whether the risk is sufficiently foreseeable and material to an appreciable segment of users, not merely whether harm is possible.
- Where an ingredient is commonly used in comparable products and reported adverse reactions are exceedingly rare, a general warning may be beyond what reasonable care requires.

## Conclusion

The court relieved the manufacturer of liability for failing to warn of a statistically remote allergic reaction to a commonly used deodorant ingredient, holding that reasonable care did not require a general allergy warning where the product was safe for most people and adverse reactions were extremely uncommon.


Kaempfe v. Lehn & Fink Prods. Corp., 21 A.D.2d 197, 249 N.Y.S.2d 840 (1st Dep’t 1964), aff’d, 20 N.Y.2d 818, 231 N.E.2d 294, 284 N.Y.S.2d 708 (1967)