Marketing claims are a subset of product liability claims. With a marketing defect claim, the plaintiff claims that the manufacturer failed to adequately warn about the dangerous propensities of its product or has failed to provide adequate instructions for the safe use of the product. Courts have held, “A defendant's failure to warn of a product's potential dangers when warnings are required is a type of marketing defect." Grinnell, 951 S.W.2d at 426 (citing Caterpillar, Inc., 911 S.W.2d at 382; Lucas, 696 S.W.2d at 377). “The existence of a duty to warn of dangers or instruct as to the proper use of a product is a question of law." Id. (citing Firestone Steel, 927 S.W.2d at 613; General Motors Corp. v. Saenz, 873 S.W.2d 353, 356 (Tex. 1993)). “Generally, a manufacturer has a duty to warn if it knows or should know of the potential harm to a user because of the nature of its product." Id. (citing Bristol-Myers Co. v. Gonzales, 561 S.W.2d 801, 804 (Tex. 1978)).

“Nevertheless, [Texas courts have] recognized that there is no duty to warn when the risks associated with a particular product are matters ‘within the ordinary knowledge common to the community.’" Id. (quoting Joseph E. Seagram & Sons, Inc. v. McGuire, 814 S.W.2d 385, 388 (Tex. 1991)); Roland v. DaimlerChrysler Corp., 33 S.W.3d 468, 470 (Tex.App.—Austin 2000, pet. denied) (truck manufacturer had no duty to warn passenger of open and obvious danger from riding in the bed of a pickup truck); Allen v. W.A. Virnau & Sons, Inc., 28 S.W.3d 226, 234 (Tex.App.—Beaumont 2000, pet. denied) (retailer had no duty to warn of dangers in operating tractor without seat belt and rollover protection system); Keene v. Strum, Ruger & Co., 121 F.Supp.2d 1063, 1069 (E.D. Tex. 2000) (no duty to warn about dangers of firearms). However, this is an “extraordinary defense," and “the standard for finding common knowledge as a matter of law is a strict one." Grinnell, 951 S.W.2d at 427. Common knowledge encompasses only those things “so patently obvious and so well known to the community generally, that there can be no question or dispute concerning their existence." Id. To establish the common knowledge defense to a failure to warn or marketing defect case, “[t]he party asserting the common-knowledge defense must establish that the dangers attributable [to the] products were a matter of common knowledge when the consumer began using the product." Id. at 428.

A recent case discussing the common knowledge defense is Humble Sand & Gravel, Inc. v. Gomez, 146 S.W.3d 170 (Tex. 2004). The primary issue in that case was whether the suppliers of flint used for abrasive blasting had a duty to warn its customers of the risks of inhaling silica dust and that an air-fed hood should be worn when working around silica dust. The Court found that the danger of inhaling silica dust and not wearing air-fed hoods had been known to flint suppliers and abrasive blasting operators for decades. Id. at 184. Consequently, the Court held the suppliers had not duty to warn the abrasive blasting operators to whom they were supplying the flint. Id. at 185. The Court then held that even though the employees did not know about the risks, this particular defendant might not have a duty to warn because of other considerations in imposing common law duties on defendants. Id. at 194.

In addition to common law exclusions of the duty to warn, statutes may also limit this duty. See, e.g., Tex. Civ. Prac. & Rem. Code Ann. § 82.004 (inherently unsafe products). In a marketing defect case, a plaintiff does not need to prove proximate cause, but only producing cause. Coleman, 40 S.W.3d at 549; General Motors Corp. v. Castaneda, 980 S.W.2d 777, 781 (Tex.App.—San Antonio 1998, pet. denied).