The principal issue in this case is whether the negligence of appellant's employer in failing to warn of or protect appellant from respondent's allegedly unsafe product constitutes an intervening act legally sufficient to operate as a superseding cause? Under the facts of this case, we hold that the employer's negligence does not constitute a superseding cause, and that the trial court *809erred in giving a jury instruction on superseding cause.
I
The facts of this case are largely undisputed. On August 29, 1980, appellant Steve Campbell was working as a wire-man with a crew for Snohomish County Public Utility District 1 (PUD) at the 52nd Street substation in Everett. The crew had performed certain maintenance upon the substation over a period of 3 days pursuant to a written switching order, under which certain portions of the substation were de-energized to permit the performance of that maintenance.
The crew completed the scheduled maintenance well in advance of the time expected. Accordingly, the crew contacted Systems Dispatch, a central clearing facility that controls all work being done in the field, to advise Systems Dispatch that the crew had completed the original work, and to secure an additional safety clearance to perform further maintenance on the substation. This additional maintenance included the cleaning of the roof bushings which are situated on top of the metal-clad switchgear.
On the day in question, the cleaning of the roof bushings included: (1) the "main bushings" through which electricity normally is conducted, and (2) the "auxiliary bushings" which normally are not used. Paint overspray and grime had accumulated on the auxiliary bushings, and the crew was instructed to wipe them clean with steel wool.
The substation has certain "feeder lines" which emerge from it to supply power to PUD customers. While the crew performed the scheduled maintenance, electrical power was not flowing through the feeder lines, and PUD customers were being provided power from another substation elsewhere in the district. However, a circuit breaker on one of those feeder lines was closed to allow power to be "backfed" from another substation to the 52nd Street substation for purposes of allowing the crew to use various electrical tools to perform their initial maintenance procedures. This back feeding caused both the main bushings and the auxiliary *810bushings to be energized while the initial maintenance was being performed.
The crew foreman contacted Systems Dispatch to de-energize the back-fed circuit so that the crew could safely clean the roof bushings. Following normal procedures, the foreman—in radio contact with Systems Dispatch—went through the standard procedures to de-energize the substation. This consisted of breaking the particular circuit that supplied the back-fed power to the substation, a procedure performed by Campbell. Following this procedure, Systems Dispatch advised the foreman that the crew could test the lines, install their grounds and proceed with their work.
After the crew tested the lines and installed the grounds, Campbell then proceeded to clean the main bushings. Upon completion of that task, and with the approval of his foreman, Campbell walked down the roof of the metal-clad switchgear to the auxiliary bushings. He reached down with a pad of steel wool in his hand to begin cleaning those bushings, only to be jarred by a high-voltage surge of electricity. Campbell was severely injured.
The auxiliary bushings remained energized after going through the normal shutdown procedures because a design feature connected those bushings to a feeder line at a point beyond the circuit breaker. As a result, the auxiliary bushings remained energized by the "back feeding" from the other substation providing power to customers. Thus, contrary to what the crew—and apparently Systems Dispatch—believed, the opening of the circuit breaker did not de-energize the auxiliary bushings.
The auxiliary bushing connection to the feeder line was obscured from the workmen's view, and the crew had no knowledge that the bushing was connected in this fashion. This unusual wiring configuration was manufactured by the respondent, ITE Imperial, as part of the switchgear equipment, and was installed under its supervision. ITE Imperial failed to provide any warning that the bushings could remain energized from a source outside the substation after normal shut-down procedures were followed. ITE Imperial *811acknowledged, however, that such a warning would not interfere in any manner with the usage or function of the equipment. Immediately after the incident giving rise to Campbell's injuries, the PUD grounded all auxiliary bushings within the system to prevent any such occurrences in the future.
Campbell contends the pertinent switchgear was not reasonably safe without a warning because the auxiliary bushings on which he was injured are wired to the load side of one of the circuit breakers in the switchgear. The PUD, Campbell's employer, allegedly specified this design when it ordered the equipment from respondent. This fact does not appear in the record because the trial court excluded it by order in limine. The court, however, was advised of this fact, and Campbell did not contradict ITE Imperial's representations to this effect until this appeal.
Campbell commenced this action on theories of strict product liability, negligence and breach of warranty. At trial, Campbell elected to proceed solely on the theory of strict liability in tort.1 Campbell testified as to the facts of the accident, injuries sustained and economic loss. The parties stipulated to the amount and reasonableness of the medical expenses.
Campbell's experts testified that ITE Imperial's product, incorporating a design configuration with the auxiliary bushings connected beyond the circuit breaker, was not reasonably safe unless accompanied by a warning. They also testified that a circuit breaker or switch between the auxiliary bushing and the connection would render the equipment safer, because back feeding from a power source outside the substation could not occur with that switch or circuit breaker open. They testified that such a configuration was both advisable and feasible from the manufactur*812er's standpoint. In fact, some of the other PUD switchgear at the time had such a circuit breaker in place. Finally, they testified that the manufacturer should have provided an insulating cap on top of the auxiliary bushing.
At the close of testimony, the trial court instructed the jury that if Campbell's employer, the PUD, was negligent in failing to discover and warn of the defect and take appropriate precautions, and if the PUD's negligence was "so unanticipated that it can be said to fall without the realm of reasonable foreseeability" by the manufacturer, then the PUD's negligence would constitute a superseding cause, thus relieving ITE Imperial of liability. The jury returned a general verdict in favor of respondent.
Thereafter, the trial court denied Campbell's motion for judgment notwithstanding the verdict on the issue of liability and for a new trial on damages only, or, in the alternative, for a new trial. Campbell appealed directly to this court. We reverse and remand for a new trial on liability and damages.
II
Campbell's primary contention is that ITE Imperial cannot avoid liability for failing to provide an adequate warning on the switchgear by claiming that the PUD should have protected him from the equipment. According to Campbell, the failure of the PUD to prevent his injury is not, as a matter of law, an intervening act that is legally sufficient to operate as a superseding cause. In short, Campbell argues that the trial court should not have instructed the jury on superseding causation.
Section 440 of Restatement (Second) of Torts (1965) defines superseding cause as "an act of a third person . . . which by its intervention prevents the actor from being liable for harm to another which his antecedent negligence is a substantial factor in bringing about." In determining whether an intervening act constitutes a superseding cause, the relevant considerations under Restatement (Second) of Torts § 442 (1965) are, inter alia, whether (1) the inter*813vening act created a different type of harm than otherwise would have resulted from the actor's negligence; (2) the intervening act was extraordinary or resulted in extraordinary consequences; (3) the intervening act operated independently of any situation created by the actor's negligence. Accord, Herberg v. Swartz, 89 Wn.2d 916, 927-28, 578 P.2d 17 (1978).
Pursuant to § 447(a) of Restatement (Second) of Torts, even if the intervening act of the third person constitutes negligence, that negligence does not constitute a superseding cause if "the actor at the time of his negligent conduct should have realized that a third person might so act". In fact,
If the likelihood that a third person may act in a particular manner is . . . one of the hazards which makes the actor negligent, such an act whether innocent, negligent, intentionally tortious, or criminal does not prevent the actor from being liable for harm caused thereby.
Restatement (Second) of Torts § 449 (1965). See also Restatement (Second) of Torts § 447, comment on Clause (a) (1965).
In Herberg v. Swartz, supra, the owner of a hotel ridden with numerous fire code violations claimed that the negligence of the local fire department was an intervening act which constituted a superseding cause. This court disagreed, stating that the "theoretical underpinning of an intervening cause which is sufficient to break the original chain of causation [i.e., constitute a superseding cause] is the absence of its foreseeability.” Herberg, at 927 (citing Boeing Co. v. State, 89 Wn.2d 443, 446, 572 P.2d 8 (1978)); Maltman v. Sauer, 84 Wn.2d 975, 982, 530 P.2d 254 (1975); Fosbre v. State, 70 Wn.2d 578, 584, 424 P.2d 901 (1967). The court stated further that "insofar as here applicable the question of whether the intervening act is a superseding cause depends upon [1] whether it brings about a different kind of harm or [2] whether it operates independently of the situation created by the actor's negligence." Herberg, at 928 (citing Restatement (Second) of Torts §§ *814442-45 (1965)). Although this court enunciated these principles in the context of a negligence action, we can think of no reason why they should not apply with equal force to a product liability action.
In this case, Campbell contends that the lack of an adequate warning near the auxiliary bushing was the proximate cause of his injury. ITE Imperial argues that the PUD's negligence in failing to warn and properly de-ener-gize the auxiliary bushing constituted a superseding cause. The question for this court is whether it was reasonably foreseeable that the PUD would either fail to provide an adequate warning or properly de-energize the substation.
The manufacturer bears responsibility for affixing an adequate warning to its product, see Teagle v. Fischer & Porter Co., 89 Wn.2d 149, 155, 570 P.2d 438 (1977), and this duty generally is not delegable. Minert v. Harsco Corp., 26 Wn. App. 867, 874, 614 P.2d 686 (1980). Thus, it would be anomalous to hold that an employer's failure to warn constituted a superseding cause. But see Little v. PPG Indus., Inc., 19 Wn. App. 812, 579 P.2d 940 (1978) (failure of employer who has actual knowledge of hazard to warn employees may constitute a superseding cause), modified, 92 Wn.2d 118, 594 P.2d 911 (1979). Such a rule might improperly shift the duty of warning to product purchasers. Although such a purchaser might be held jointly liable for breach of its duty to warn, its negligence generally should not relieve the manufacturer of liability for failure to warn. Regardless, we believe the PUD's negligence in failing to warn was reasonably foreseeable.
The PUD's failure to de-energize the auxiliary bushing likewise was foreseeable. In the first place, ITE Imperial had to be generally aware of the PUD's complicated power grid and the likelihood of human failure in de-energizing a particular portion of that grid. More importantly, the very design of the pertinent switchgear without a circuit breaker should have led a reasonable manufacturer to conclude that the PUD might fail to de-energize this particular switchgear even after following written shutdown procedures for *815that substation. The potential danger associated with power back feed from an alternate source exists with respect to all pieces of switchgear. Unlike other pieces of switchgear in the PUD's system, however, the item manufactured by ITE Imperial does not contain a circuit breaker. Thus, a workman unfamiliar with this particular design might reasonably conclude that the pertinent switchgear is de-energized after opening the circuit breakers on the other substation circuits.
Viewed differently, the intervening negligence of the PUD did not result in a different kind of harm than otherwise would have resulted from ITE Imperial's failure to warn. The harm caused by the PUD's negligence—electrical shock and burns—is identical to the harm brought about by ITE Imperial's failure to warn. Secondly, the intervening negligence of the PUD did not operate independently of the situation created by ITE Imperial's failure to warn. To use this court's language in Herberg, the PUD's negligence was "activated" by ITE Imperial's failure to affix a warning to its product.
In fact, this case falls directly within the coverage of § 449 of Restatement (Second) of Torts. Under § 449, even criminal conduct of a third party does not constitute a superseding cause ” [i]f the likelihood that a third person may act in a particular manner is.. . . one of the hazards which makes the actor negligent". In this case, the likelihood that the PUD would not properly shut down the auxiliary bushing is the very hazard which makes ITE Imperial's switchgear unreasonably unsafe if unaccompanied by an adequate warning. Accordingly, under § 449 the PUD's negligence does not constitute a superseding cause.
Notwithstanding the foregoing analysis, ITE Imperial argues that Little v. PPG Indus., Inc., supra, the first Washington case addressing the applicability of the doctrine of superseding cause to a products liability action, supports a decision favoring ITE Imperial. In Little, a workman was overcome by and died from a chemical produced by the defendant. The barrels in which the chemical *816was sold contained a warning which the plaintiff alleged was inadequate. Based upon the existence of this warning, together with evidence that the decedent's employer had specific knowledge of the chemical's dangerous propensities and of two prior employee accidents involving the chemical, the court held that the issue of superseding cause based on the employer's negligence should be presented to the jury on retrial. Little, at 825.
ITE Imperial relies heavily upon Little and other cases involving an employer's failure to warn to justify the jury instruction in this case. There are, however, two important factual differences between Little and this case. First, unlike ITE Imperial, the manufacturer in Little had "no effective means of communicating its warnings to the ultimate user." (Footnote omitted.) Little, at 824. The evidence in Little demonstrated that the manufacturer's chemical was pumped out of its barrels into containers belonging to the employer. One could hardly expect the manufacturer to assume responsibility for affixing warnings to every container in which its chemical might be used. In this case, however, ITE Imperial had an effective means of communicating its warning to PUD employees; namely, by affixing an inexpensive warning to the roof of the substation in proximity to the auxiliary bushings.
Furthermore, in Little, the employer had actual, specific knowledge that the product was unreasonably unsafe, and that four employees had been overcome by the chemical on two previous occasions. Little, at 825. In this case, on the other hand, the record is barren of evidence that the PUD actually knew the switchgear was unreasonably unsafe, and no employee accidents involving this switchgear had ever occurred.
Dean Prosser, upon whom the Little court heavily relied, states that "[w]here the buyer is notified of the danger, or discovers it for himself, and delivers the product without warning, it usually has been held that the responsibility is shifted to him, and that his negligence supersedes the liability of the seller." (Footnotes omitted.) W. Prosser, Torts *817§ 102, at 667-68 (4th ed. 1971). Assuming this court were to adopt this principle, it does not apply to this case. In short, we believe Little can and should be distinguished on the grounds that (1) ITE Imperial had an effective means of communicating its warning to PUD employees; and (2) the PUD did not have actual, specific knowledge that the switchgear was unreasonably unsafe.
In sum, we hold that an employer's failure to warn or protect an employee from a product which is unreasonably unsafe, unless accompanied by a warning, does not constitute a superseding cause, unless (1) the employer's intervening negligence created a different type of harm; or (2) the employer's intervening negligence operated independently of the danger created by the manufacturer; or (3) the employer had actual, specific knowledge that the product was unreasonably unsafe and failed to warn or protect. Because there is no such evidence in the record of this case, the trial court erred in giving a superseding cause instruction. Accordingly, we reverse and remand for a new trial. Because we hold that ITE Imperial was not entitled to an instruction on superseding cause, we need not address Campbell's challenge to the superseding cause instruction given at trial.
Ill
After the jury returned its general verdict in favor of respondent, Campbell moved the court for entry of judgment notwithstanding the verdict on the issue of liability, and for a new trial on the issue of damages. In the alternative, Campbell also moved for a new trial on all issues. The trial court denied the motions and Campbell contends this was error.
With regard to entry of judgment notwithstanding the verdict, the test to be applied in ruling on such a motion was succinctly stated by this court in Hojem v. Kelly, 93 Wn.2d 143, 145, 606 P.2d 275 (1980), as follows:
A motion for a judgment n.o.v. should not be granted unless the court can say, as a matter of law, that there is *818neither evidence nor reasonable inference therefrom sufficient to sustain the verdict. All evidence must be viewed in the light most favorable to the party against whom the motion is made. Grange v. Finlay, 58 Wn.2d 528, 364 P.2d 234 (1961). There must be "substantial evidence" as distinguished from a "mere scintilla" of evidence, to support the verdict—i.e., evidence of a character "which would convince an unprejudiced, thinking mind of the truth of the fact to which the evidence is directed." A verdict cannot be founded on mere theory or speculation. Arnold v. Sanstol, 43 Wn.2d 94, 98, 260 P.2d 327 (1953).
The Hojem court affirmed the trial court's entry of judgment n.o.v. for the reason that, "at best", a mere scintilla of evidence had been presented to support the jury verdict. That is, since substantial evidence did not exist, entry of judgment n.o.v. was proper.
In the present case, the evidence adduced at trial conflicted on the issue of whether the switchgear was unreasonably unsafe unless accompanied by a warning. In particular, ITE Imperial's expert witness testified with respect to the switchgear that: "Safety is related to the usage, and not to its configuration"; and, "[t]he switchgear ... by design is very safe." Verbatim Report of Proceedings, at 399. Based upon this evidence, the jury might have concluded that the pertinent switchgear was reasonably safe. In short, we believe the jury was presented with sufficient evidence, such that the trial court could not say, as a matter of law, that ITE Imperial was not entitled to the jury's verdict. Therefore, we affirm the trial court's denial of Campbell's motion for judgment n.o.v.
IV
ITE Imperial cross-appeals the trial court's order in limine rejecting ITE Imperial's proffer of evidence that the pertinent switchgear was manufactured to the PUD's specifications. Interestingly, although ITE Imperial's expert testified that the design was safe, ITE Imperial argues that the fact that the PUD designed the pertinent switchgear is relevant to the issue of the reasonable foreseeability of the PUD's negligence as a superseding cause. Because this evi*819dence was excluded, there is no way for this court to determine whether the PUD actually did design the switchgear.
In any event, participation by the PUD in the design of the product in this case should not relieve ITE Imperial of the duty to warn where a warning is required. A claim for injury resulting from design defect is distinct from a claim of harm resulting from a failure to warn. Should the manufacturer be found liable for the absence or inadequacy of a warning, it may seek contribution from the designer for the defective design. This, however, has nothing to do with a plaintiff's cause of action. In short, because the PUD's failure to warn or protect Campbell is, at best, a concurring rather than a superseding cause, the design origin is irrelevant.
Accordingly, we affirm the trial court's refusal to give ITE Imperial's instruction 16. We hold, under the facts of this case, that admission of design origin was not relevant to the issue of whether ITE Imperial's product is unreasonably unsafe unless accompanied by a warning, and might have confused the jury by intimating that the PUD's fault can relieve ITE Imperial of liability for its failure to warn. We affirm the trial court's refusal to give ITE Imperial's instruction 15 that an employer's knowledge that a product is dangerous relieves a manufacturer from liability for failure to warn because there is no evidence that the PUD had actual, specific knowledge that the switchgear was unreasonably unsafe.
V
ITE Imperial also cross-appeals the trial court's refusal to give ITE Imperial's instruction 14 on assumption of risk. According to ITE Imperial, it is entitled to this instruction on remand because there is evidence in the record that Campbell knew there always was the possibility of unexpected energy in PUD equipment. ITE Imperial's position is untenable.
In a strict liability case, assumption of the risk operates as a damage-reducing factor rather than a complete *820bar to recovery. Davis v. Globe Mach. Mfg. Co., 102 Wn.2d 68, 75, 684 P.2d 692 (1984) (citing South v. A.B. Chance Co., 96 Wn.2d 439, 635 P.2d 728 (1981)). An assumption of risk instruction is proper when there is substantial evidence that the plaintiff knew of the specific defect causing his injury. Davis, at 75-76 (citing Klein v. R.D. Werner Co., 98 Wn.2d 316, 318, 654 P.2d 94 (1982)).
In this case, it is uncontroverted that Campbell was not aware of either the configuration of the 52nd Street substation, or the fact that the auxiliary bushing was energized. As an experienced wireman, working with high voltage on a daily basis, Campbell surely was aware of the general dangers, but obviously was unaware that the auxiliary bushing would remain energized after opening the circuit breakers. To conclude that Campbell was aware of the specific defect in this configuration would be tantamount to believing that he intended to commit suicide. See Pearson v. Hevi-Duty Elec., 618 S.W.2d 784, 790 (Tex. Civ. App. 1981). Thus, we hold the trial court properly refused ITE Imperial's instruction 14 because there is not substantial evidence that Campbell touched the auxiliary bushing with specific knowledge that the bushing was energized.
Utter, Brachtenbach, Dolliver, Dore, Andersen, and Durham, JJ., concur.Because Campbell commenced this action prior to the effective date of the pertinent provisions of the tort reform act, Laws of 1981, ch. 27, codified at RCW 7.72, we express no opinion on the effect of the act on any aspect of Campbell's case, but note that the act would have no effect on our discussion of superseding cause.