Plaintiff-appellee can hardly be deemed a professional or skilled artisan; she was an unskilled worker who had worked in Mennen's electrode department for only ten months. The knowledgeable user exception has not been applied to lay persons, even those with some familiarity with the product. See, e. g., Young v. Elmira Transit Mix, Inc., 52 A.D.2d at 204, 383 N.Y.S.2d at 730 (do-it-yourself builder with some experience with cement); Haberly v. Reardon Co., 319 S.W.2d at 867-68 (do-it-yourself painter with knowledge that paint could injure eyes).

Assuming that appellee could fall within the knowledgeable user exception, however, we must decide whether the district court should have held her knowledgeable as a matter of law, or whether the question of her knowledge was properly submitted to the jury as a question of fact.

To support their contention that plaintiff should have been deemed a knowing user as a matter of law, appellants rely on plaintiff's testimony that she had read the warning label on the Scotchcast container and that her supervisor had warned her not to get the product on her skin, as well as on evidence that plaintiff had experienced the toxic effects of the resin on prior occasions and had received medical attention for it.

Appellants apparently argue that as long as Billiar knew the product was dangerous, she was sufficiently knowledgeable to fall within the exception; the fact that she was ignorant of the severity of the danger is immaterial. As we read the cases, appellants are mistaken.

Plaintiff argues that the Scotchcast label did not inform her of the severity of the injury she could receive from skin contact with Scotchcast. The evidence showed that she had never been similarly injured before, and that her prior reaction was limited to tiny blisters on her fingers, which her doctor had treated only with a glycerine salve. Thus while she testified that she knew the product was harmful to skin, she also stated that she did not know how extremely harmful it could be.

The extent of plaintiff's knowledge of the danger was thus in dispute. In such a case, New York courts have left the question whether there was a duty to warn to the trier of fact. See Rosebrock v. General Electric Co., 236 N.Y. at 237, 140 N.E. at 574; Young v. Elmira Transit Mix, Inc., 52 A.D.2d at 205, 383 N.Y.S.2d at 731; see also Haberly v. Reardon Co., 319 S.W.2d at 867-68 (applying New York law).

In Haberly v. Reardon Co., 319 S.W.2d 859 (Mo.1958) (applying New York law), plaintiff, a 12-year old boy, was blinded when a small quantity of cement-based paint accidentally got in his eye while he was helping his father. The father, who was not a professional painter, had read the warning on the box stating that the paint contained Portland cement, that the product's alkalinity could be irritating to tender or sensitive skin, and that prolonged contact with the skin should be avoided. In addition the father testified that he knew that paint of any kind would hurt the eye. Nevertheless, the court held that New York law would permit the jury to find that the defendant had breached its duty to warn of the danger. Id. at 867-68.

More recently, in Young v. Elmira Transit Mix, Inc., 52 A.D.2d 202, 383 N.Y.S.2d 729 (4th Dep't 1976), a do-it-yourself home builder sued the supplier of Portland cement to recover for burns suffered from contact with the cement. The supplier had provided no warning at all, although he knew that wet cement could cause severe caustic burns. Plaintiff testified at trial that he had worked with cement for over 30 years on odd jobs, but had never been burned before; that he knew that cement contained lime, but did not know that contact with it could burn his skin; that he knew that an open cut exposed to wet cement would get sore and take longer to heal. The trial court instructed the jury that evidence of plaintiff's knowledge of cement was to be given whatever weight they considered appropriate and charged them as follows:(T)he manufacturer of a product which is reasonably certain to be dangerous if used in a way in which he should reasonably foresee it would be used is under a duty to exercise reasonable care, to give reasonable and adequate warning of any dangers known to him or which, in the exercise of reasonable care, he should have known and which the user of the product ordinarily would not discover. Reasonable care means that degree of care which a reasonably prudent concrete manufacturer would exercise under the same circumstances.

Id. at 205, 383 N.Y.S.2d at 731. This instruction closely tracks the language of Section 388 of the Restatement of Torts, 2d edition,1 and served as the model for Judge Curtin's charge in the instant case.

On appeal, the defendant in Young argued, inter alia, that he had no duty to warn plaintiff of the danger because the dangerous properties of cement are well known and because plaintiff had testified to his own knowledge of the harmful effects of wet cement on the skin. The Appellate Division, while noting that "(c)ement is an ancient product" and that "dangers of irritations and burns from (lime) have been known for centuries," id., 383 N.Y.S.2d at 730, held that Restatement § 388 controls and that the question of whether defendant had a duty to warn was properly submitted to the jury. Id. at 731.

Young does not discuss the knowledgeable user doctrine, but the extent of the plaintiff's knowledge of the dangers of cement was vigorously argued by the supplier on appeal. As Restatement § 388 does not focus on the plaintiff's actual knowledge, but on the supplier's reasonable expectations, the Appellate Division may have concluded that a supplier should not be freed of liability merely because, despite negligent failure to warn, the plaintiff happened to have actual knowledge. Alternatively, the Appellate Division may have thought that the user's partial knowledge in Young could not be held sufficient as a matter of law to exempt the supplier from its duty to warn, but was one fact to be considered by the jury. In approving the submission of the question of duty to warn to the jury, the court, at a minimum, held that it was for the trier of fact to decide whether a duty existed in the circumstances. Id. at 731. Young seems to us to be strong authority for the submission of the question of duty to warn to the jury when the user is a nonprofessional with some knowledge of the harmful propensities of the product.

We do not agree with appellants that Young is inapplicable because the defendant in that case supplied no warning whatsoever. Where, as here, the supplier has provided some warning, plaintiff's knowledge of that warning could be dispositive only if the warning was clearly adequate. Cf. Rosebrock v. General Electric Co., 236 N.Y. at 235, 140 N.E. at 573; Butler v. L. Sonneborn Sons, Inc., 296 F.2d 623, 624, 626 (2d Cir. 1961) (applying general tort principles). The duty is not merely to warn, but to warn adequately. It would be anomalous to hold that providing an inadequate warning could exempt the supplier of a dangerous product from this duty. Thus, on the facts of the instant case, determining the adequacy of the warning was essential to determining plaintiff's knowledge of the danger.

Unless we could hold as a matter of law that plaintiff's knowledge, aside from or in combination with knowledge derived from reading the label, was sufficient to apprise her fully of the danger, the question of the adequacy of the warning was correctly submitted to the jury. We cannot so hold. Here, plaintiff had read the warning and knew, in addition, that contact with Scotchcast could cause blisters on her fingers. This is not necessarily equivalent to knowledge that contact with the product could cause severe chemical burns.

We conclude that New York law would allow the jury to decide whether plaintiff was sufficiently aware of the danger to exempt the supplier from its duty to warn. The district court instructed the jury that they were to consider the extent of plaintiff's knowledge of the danger in determining whether defendant had fulfilled its duty to warn adequately. We find that charge correct on the facts of this case.

Mennen, citing Hafner v. Guerlain, Inc., 34 A.D.2d 162, 310 N.Y.S.2d 141 (1st Dep't 1970), argues that New York law places no duty on a manufacturer to foresee and warn against the remote possibility that a small number of users will experience a severe reaction. The Hafner case turned on a finding that the manufacturer could not have reasonably foreseen the likelihood that its widely-sold perfume would cause plaintiff's highly abnormal allergic reaction. If the injury is reasonably foreseeable, however, even if rare, the seller cannot rely on its history of good fortune to exempt itself from liability. See Butler v. L. Sonneborn Sons, Inc., 296 F.2d at 626. Here, the evidence showed that 3M had reason to foresee that chemical burns such as Billiar's could result from skin contact with Scotchcast. Indeed, the warning label provided by 3M evinces its awareness that contact with skin could be harmful. The fact that Mennen had never experienced a similar injury among its workers is irrelevant to 3M's duty to warn.

The appellants argue, Mennen explicitly and 3M implicitly, that the trial court should have found the warning adequate as a matter of law because the label mentioned Scotchcast's toxic and caustic components. To our knowledge, no case applying New York law has held a warning adequate as a matter of law.2 Moreover, we could overturn the verdict only if we concluded that no rational jury could have decided on the evidence that a clearer, stronger, or more explicit warning was called for under the circumstances. See Simblest v. Maynard, 427 F.2d 1, 4 (2d Cir. 1970); Stief v. J.A. Sexauer Manufacturing Co., 380 F.2d 453, 462 (2d Cir.), cert. denied, 389 U.S. 897, 88 S. Ct. 220, 19 L. Ed. 2d 216 (1967). In light of the recommendations of the Manufacturing Chemists Association and testimony that the potency of diethylenetriamine was not diminished when mixed with the other components of Scotchcast, there was clearly evidence from which a jury could conclude that 3M failed to warn adequately of the dangers of the product.

Mennen also contends that in the absence of expert evidence on what a more adequate label should have provided, the jury could have found the warning inadequate only by engaging in speculation. This argument is meritless. Under New York law, the jury does not need expert testimony to find a warning inadequate, but may use its own judgment considering all the circumstances. See Young v. Elmira Transit Mix, Inc., 52 A.D.2d at 205, 383 N.Y.S.2d at 731; Rainbow v. Elia Building Co., 49 A.D.2d 250, 253, 373 N.Y.S.2d 928, 931 (4th Dep't 1975).

Next, Mennen argues that even if the warning was inadequate, this inadequacy was not shown to be the proximate cause of the plaintiff's injury. Since plaintiff testified that she brushed her face with her hand "inadvertently," Mennen claims that she would have behaved the same way even if a more adequate warning had been provided.

This ingenious argument rests not on proven fact, but on the dubious premise that a person will be equally careless whether the harm risked is great or slight. We cannot hold as a matter of law that a clear warning that severe chemical burns might result would not cause a reasonably prudent person to be more careful than she would be if the only known risk were slight blistering. See Haberly v. Reardon Co., 319 S.W.2d at 867.

The New York rule, cited by Mennen itself, is clear:

The negligence of the defendant cannot be excluded as one of the actual causes of the accident, unless it can be said with certainty that, even if the defendant had not been negligent, the accident would nevertheless have happened. It is not enough to speculate "that the same harm might possibly have been sustained had the actor not been negligent." Restatement of Torts, § 432, comment "c". The negligent act must be regarded as one of the actual causes of the injury if it was a substantial factor in bringing the injury about.

Rugg v. State, 284 A.D. 179, 131 N.Y.S.2d 2, 6 (3d Dep't 1954) (emphasis added). The district judge correctly instructed the jury that proximate causation requires finding that defendant's negligence was a material and significant factor contributing to plaintiff's injury. The jury's finding of such causation was not against the weight of the evidence.

The final issue is whether the allocation by the jury of 68% of the fault to Mennen was against the weight of the evidence.

We agree with the district court that there was ample evidence in the record to support the jury's determination. The only protective clothing Mennen supplied to plaintiff were smocks and rubber gloves with cut-off fingers. Moreover, Mennen did not require, instruct or even encourage plaintiff to wear such protective clothing, but merely made it available. There was some evidence from which a jury could find that Mennen did not attempt to impress upon plaintiff the extreme hazard posed by Scotchcast.

Further, plaintiff's supervisor testified that she did not require plaintiff to read the warnings printed on the Scotchcast cans; that she gave no safety instructions to plaintiff aside from telling her to wash her hands and not to touch her face; that she did not instruct plaintiff to use soap and water, although these were provided; and that she gave no safety warnings after the first day, at which time plaintiff was also instructed on how to perform the complex procedural steps of making electrodes. In addition, there was undisputed evidence that Mennen decided what implements to provide. The choice of tongue depressors and small paper cups for mixing these caustic chemicals was further evidence of Mennen's cavalier attitude toward plaintiff's safety.

When a jury's determination is based on an interpretation of facts within their sphere, New York law does not permit a reviewing court to set aside the verdict unless the evidence so preponderates in favor of the party against whom the verdict was rendered that it is clear that the jury did not reach its conclusion on a fair interpretation of the evidence, Calabrese v. Ontario County, 58 A.D.2d 1008, 1009-10, 397 N.Y.S.2d 493, 495 (4th Dep't 1977); Marshall v. Mastodon, Inc., 51 A.D.2d 21, 23, 379 N.Y.S.2d 177, 180 (3d Dep't 1976), or if a contrary conclusion is the only reasonable inference that can be made from the proven facts. Zipay v. Benson, 47 A.D.2d 233, 235, 365 N.Y.S.2d 920, 922 (3d Dep't 1975). The federal standard in this circuit is virtually identical. See Mattivi v. South African Marine Corp., "Huguenot," 618 F.2d 163, 167-68 (2d Cir. 1980); Simblest v. Maynard, 427 F.2d at 4.

We find that there was sufficient evidence from which a jury could reasonably determine that Mennen failed to caution, instruct and supervise plaintiff adequately and that it did not fulfill its duty as charged by the trial judge to provide plaintiff with a safe place to work in regard to use of Scotchcast.

If there was ever an English word whose meaning is crystal clear, that word is "caustic". The Century Dictionary of 1895 said that it meant "capable of burning, corroding, or destroying the tissue of animal substances." The New Century Dictionary (1931) defines it as "capable of burning, corroding, or destroying animal tissue." In Webster's Third New International Dictionary (1971) "caustic" is defined as "capable of destroying the texture of anything or eating away its substance by chemical action" and "capable of destroying animal or other organic tissue." Webster's New Elementary Dictionary, intended for use by school children in the elementary grades, says that "caustic" means "capable of destroying or eating away by chemical action." It is the "caustic" action of chemical drain cleaners that destroys the organic matter in clogged drains and that can be equally injurious to human tissue.

When the label on a product urges "CAUTION", stating that the product contains caustic components and that contact with the skin should be avoided, preferably by use of protective clothing, I suggest that no reasonable person can be in doubt as to what she is being warned against. When, as in the instant case, the plaintiff has been using the product for 10 months, has been warned orally that it could be harmful to her skin, and on several occasions has burned her hands seriously enough to require medical treatment, I can see no basis whatever for a finding that she is the innocent victim of inadequate warning. I would reverse. See Verdiglione v. Ridge Lumber, Inc., 23 A.D.2d 817, 258 N.Y.S.2d 471 (1965), aff'd, 17 N.Y.2d 740, 270 N.Y.S.2d 208, 217 N.E.2d 33 (1966); Stief v. J. A. Sexauer Manufacturing Co., 380 F.2d 453 (2d Cir.), cert. denied, 389 U.S. 897, 88 S. Ct. 220, 19 L. Ed. 2d 216 (1967); Moschkau v. Sears, Roebuck and Co., 282 F.2d 878 (7th Cir. 1960); Hunter v. E. I. du Pont de Nemours & Co., 170 F. Supp. 352 (W.D.Mo.1958).