Plaintiff Robert Rose sued Highway Equipment Company (HECO), the manufacturer of a broadcast spreader, after Rose severely injured his hand while oiling the spreader’s chain.3 Rose’s suit asserted causes of action for negligence and breach of the implied warranty of merchantability. On the negligence count, the jury found Rose seventy-three percent negligent and HECO twenty-seven percent negligent, which foreclosed recovery. See G. L. c. 231, § 85. On the breach of warranty claim, the jury answered “yes” to the special question whether Rose’s use of the spreader was unreasonable, barring Rose from recovery on that claim. See Correia v. Firestone Tire & Rubber Co., 388 Mass. 342, 355 (1983) (Correia). On appeal, Rose claims that certain jury instructions created reversible error. We affirm.4
The jury heard various accounts of how Rose’s hand became caught in the spreader. It was uncontested that the spreader needed to be running in order for its chain to be effectively oiled. Rose explained that, before the accident, he was kneeling or crouching between the cab of the truck and the spreader, using something akin to a Windex bottle to spray oil on the chain. Rose testified that he suddenly felt a tug at the sleeve of his sweatshirt and was unable to extricate himself from the grip of the spreader before his right hand and forearm were pulled into the mechanism.5 After the accident, Rose told his boss, who is also his father-in-law, that he was injured when reaching backwards for the bottle of oil. In contrast, it was HECO’s theory that Rose, after drinking beer earlier that afternoon, lost his balance while on a ladder on the operator’s side of the truck and fell into the spreader.
Unlike an action in negligence, a breach of warranty claim primarily concerns the nature of the product, not the actions of the user. Colter v. Barber-Greene Co., 403 Mass. 50, 61-62 (1988). See Correia, supra. While a factfinder in a warranty claim must focus on the characteristics of the product, the duty “to act rea*206sonably” is imposed on the product’s user. Ibid. “When a user unreasonably proceeds to use a product which he knows to be defective and dangerous, he violates that duty and relinquishes the protection of the law.” Ibid. The apportionment principles used in negligence claims, which permit a plaintiff to recover as long as his negligence equates to less than the negligence attributed to the defendant, are not applicable to warranty cases. The defense of unreasonable use provides a complete bar to recovery. Ibid.
Contrary to Rose’s claim, the evidence at trial was sufficient to support the judge’s submission of the unreasonable use defense to the jury, in both the form of a jury instruction and a special verdict question. Rose testified that he oiled the spreader’s chain multiple times, from the back of the unit and the front. Rose’s boss testified that he instructed Rose to stay away from the front of the spreader when he was oiling it.6 Rose’s boss also testified that Rose understood that oiling the chain was potentially dangerous. Rose admitted that although he was instructed to oil the chain from the back of the truck, he chose to oil the chain from the front because he thought that it would be easier. On cross-examination, Rose also admitted that he saw the spreader’s warning label, but never read it. Similarly, Rose testified that he was familiar with the spreader’s safety manual, but had not read it. Rose testified that he never thought about whether it was dangerous to oil the chain, but he was impeached with his deposition testimony that he understood that “[i]f you put your hand in [the spreader], you could get hurt.”
While there was conflicting evidence about the amount of alcohol he consumed on the day of the accident, Rose’s decision to drink beer before oiling the spreader also supported the judge’s decision to instruct the jury on unreasonable use. Both parties presented toxicology experts, and the jury were permitted to credit HECO’s expert, who testified that, based on blood test results taken at two area hospitals, Rose’s blood alcohol level *207would have been 0.13 or higher at the time of the accident. This would have been possible, HECO’s expert explained, only if Rose consumed many more than the two beers he testified about drinking before the accident.
Rose claims that HECO failed to prove that he subjectively knew that the spreader was defective and that he subjectively knew of the danger and the magnitude of the risk of injury. In order to prevail on the Correia defense, a defendant must “demonstrate that the plaintiff ‘subjectively knew that the product was defective and dangerous, [and] that, despite that subjective belief, the plaintiff’s use of the product was objectively unreasonable, and that the plaintiff’s conduct was a cause of the injury.’ ” Haglund v. Philip Morris Inc., 446 Mass. 741, 749 (2006), quoting from Cigna Ins. Co. v. Oy Saunatec, Ltd., 241 F.3d 1, 17 (1st Cir. 2001). While the burden was on HECO to show Rose’s subjective knowledge, HECO was not required to prove this solely through a direct admission by Rose. Rose’s testimony about his familiarity with operating the spreader and other types of heavy machinery, his inconsistent statements about his understanding of the spreader’s danger, the fact that Rose’s boss instructed him to oil the chain from the back and testified that he believed Rose understood the dangers that oiling the spreader presented, along with evidence that Rose consumed alcohol before the accident, taken together, provided the judge with a suitable basis to present the unreasonable use defense to the jury.7
Rose also claims that the judge improperly explained the subjective knowledge requirement to the jury. We disagree. When a *208defendant asserts the Correia defense, proof of the “plaintiff’s subjective knowledge of a product’s defect need not be technically specific; ‘it is enough to show that the plaintiff knew the product was defective in some way, rather than showing that it knew the technical elements of the defect.’ ” Haglund v. Philip Morris Inc., supra, quoting from Cigna Ins. Co. v. Oy Saunatec, Ltd., supra at 19. Here, the judge instructed the jury that “HECO alleges the affirmative defense that the plaintiff knowingly, voluntarily and unreasonably used a product which he knew to be defective and dangerous, and as a result that he was injured.” The judge also stated that it was the defendant’s burden of proof to show that the plaintiff “knew of the product’s defect and its danger” and explained furthermore that “prior to the accident, the plaintiff must have had knowledge of the product’s defect, and the danger present, and must have proceeded to use the product with an appreciation of this known danger.” This was a sufficient explanation of HECO’s duty to show Rose’s subjective understanding of the defect and danger.
Finally, Rose challenges the judge’s use of the phrase “the implied warranty version in effect of the contributory negligence defense described earlier” to segue between describing the implied warranty claim and its affirmative defense of unreasonable use. When read in context, “the implied warranty version in effect” language was likely meant to serve as an introductory signal to the jury, one that indicated that the unreasonable use defense was an affirmative defense, similar in general nature to the affirmative defense of comparative negligence that the judge had just explained following the negligence charge. Rose claims that the phrase should be read as one that improperly harmonized the absolute defense of warranty liability with the apportionment *209liability principles of negligence. We disagree. Indeed, the jury were never instructed to weigh Rose’s conduct in relation to HECO’s on the warranty claim. Instead, the judge described to the jury what it must find in order to characterize Rose’s use of the spreader as unreasonable. A thorough and proper explanation of the elements of the unreasonable use defense followed the challenged remarks, minimizing the risk that the jury conflated the two defenses. Also relevant is the fact that the judge, multiple times in his instructions, underscored for the jury that the two claims, negligence and warranty liability, were distinct.
Finally, the judge described the unreasonable use defense as the “version in effect of the contributory negligence defense described earlier,” instead of the comparative negligence defense. The judge gave a thorough comparative negligence instruction, but he also referenced Rose’s “contributory negligence.” While the judge misspoke, the jury were not likely to improperly rely on contributory negligence principles to reach its verdict, because the judge never explained the concept of contributory negligence to the jury. In this context, the judge’s use of the word “contributory” instead of “comparative,” which neither party objected to, was unlikely to hinder the jury’s understanding of the unreasonable use defense.
When considering the approximately fifty pages of jury instructions given in this case, including elaborate and repetitive descriptions of the elements of the two claims and their affirmative defenses, we conclude that the inclusion of the challenged phrase does not require reversal of the jury’s verdict. When read as a whole, we are satisfied that the judge “clearly, adequately, and correctly explained to the jury the principles that ought to guide and control” their deliberations. Torre v. Harris-Seybold Co., 9 Mass. App. Ct. 660, 678 (1980).
Judgment affirmed.