
Vol. 78, No. 3, March 
2005
The Sophisticated User Doctrine Arrives
The sophisticated user doctrine may insulate a manufacturer from a 
negligence claim when a person or company that purchases a product as 
knowledgeable as the manufacturer about the product's hazards. The 
doctrine may have arrived, but questions remain about its scope, among 
other issues.
 
Sidebars:
 by 
Kevin D. Trost
by 
Kevin D. Trost
Last summer the Wisconsin Supreme Court tacitly gave manufacturers in 
Wisconsin another defense against lawsuits that allege a manufacturer 
negligently failed to provide adequate warnings with its products. In 
Haase v. Badger Mining Corp.,1 the 
court let stand without comment a published court of appeals decision 
that borrowed the sophisticated user doctrine from Iowa law. The supreme 
court declined to address the lower court's importation of the 
sophisticated user doctrine, citing the appellant's failure to appeal 
the negligence claim that was dismissed under that doctrine. This 
silence has solidified the lower court's published ruling, and a 
subsequent court of appeals decision that invokes this ruling, and it 
has opened the door to the introduction of the sophisticated user 
doctrine in Wisconsin jurisprudence.
What is the Sophisticated User Doctrine?
The sophisticated user doctrine insulates a manufacturer from 
negligence claims that are based on the failure to warn. When the person 
or entity purchasing a product is as knowledgeable about the product's 
hazards as the manufacturer is, the manufacturer bears no duty to warn 
the purchaser of the hazards. In such a situation the purchaser is 
considered to be more knowledgeable about the end use of the product and 
is therefore in a better position than the manufacturer to provide 
meaningful warnings and instructions to anyone actually using the 
product.2 For example, a foundry that 
purchases sand for use in its casting operations is in a better position 
than the sand manufacturer to communicate to foundry employees the 
dangers of the product and to instruct in proper protective 
measures.
 Kevin D. Trost, U.W. 1998, is a senior associate at 
Axley Brynelson LLP, Madison. His practice is concentrated in the areas 
of products liability, personal injury, and environmental litigation. He 
has both defended and prosecuted failure to warn claims affected by the 
sophisticated user doctrine.
Kevin D. Trost, U.W. 1998, is a senior associate at 
Axley Brynelson LLP, Madison. His practice is concentrated in the areas 
of products liability, personal injury, and environmental litigation. He 
has both defended and prosecuted failure to warn claims affected by the 
sophisticated user doctrine.
 
This doctrine is rooted in Restatement (Second) of Torts § 388 
(1965), a specific section that Wisconsin has adopted.3 This section of the Restatement states:
"Chattel Known to be Dangerous for Intended Use.
"One who supplies directly or through a third person a chattel for 
another to use is subject to liability to those whom the supplier should 
expect to use the chattel with the consent of the other or to be 
endangered by its probable use, for physical harm caused by the use of 
the chattel in the manner for which and by a person for whose use it is 
supplied, if the supplier
"(a) knows or has reason to know that the chattel is likely to be 
dangerous for the use for which it is supplied, and
"(b) has no reason to believe that those for whose use the chattel is 
supplied will realize its dangerous condition, and
"(c) fails to exercise reasonable care to inform them of its 
dangerous condition or of the facts which make it likely to be 
dangerous."
Subsection (b) has been widely interpreted to embody the 
sophisticated user doctrine and to establish that there is "no duty to 
warn if the user knows or should know of the potential danger, 
especially when the user is a professional who should be aware of the 
characteristics of the product."4
The Emergence of the Doctrine in Wisconsin
The Wisconsin Court of Appeals first explicitly raised the doctrine 
and Restatement (Second) of Torts § 388(b) as its grounds for 
dismissing a plaintiff's claim in Haase v. Badger Mining 
Corp.5 Haase, a long-term employee of 
the Neenah Foundry, was diagnosed with silicosis. He then sued Badger 
Mining, the company that provided the foundry with silica sand.6 The foundry casting process pulverizes the silica 
sand, creating clouds of visible silica dust and silica particles so 
minute that they can become lodged in the lungs of exposed 
workers.7 The particles cannot be expunged 
from the lungs and can cause the progressive respiratory disease 
silicosis. Haase argued that the seller of the sand knew that foundries 
were one of the prime consumers of its sand, knew that silica sand broke 
down into minute respirable particles during the foundry casting 
process, and failed to warn workers how to adequately protect themselves 
from respiratory harm.8 Both the trial court 
and the court of appeals agreed with Badger Mining that the Neenah 
Foundry was as sophisticated and knowledgeable as Badger Mining about 
the dangers of silicosis and how to protect workers from respirable 
silica.9 As a result, the sophisticated user 
doctrine relieved Badger Mining of its duty to provide a specific 
warning to the foundry workers.
After Haase, the Wisconsin Court of Appeals quickly extended 
the reach of the sophisticated user doctrine beyond the 
employer/employee context. In Mohr v. St. Paul Fire & Marine 
Insurance Co., a high school swim team member was injured while 
diving from a diving board into a shallow portion of the high school's 
swimming pool.10 The swimmer sued the 
diving board manufacturer, claiming the manufacturer was negligent for 
failing to warn him of the dangers of locating the platform at a shallow 
depth.11 The manufacturer contended it bore 
no duty to warn because the high school was a sophisticated user that 
belonged to the Wisconsin Interscholastic Athletic Association (WIAA), 
an organization that monitors national standards and provides its member 
high schools with information on the safe practice of sports 
activities.12 The Wisconsin Court of 
Appeals found that the sophisticated user doctrine was applicable, but 
determined there was insufficient factual information about the extent 
of the manufacturer's knowledge about the high school to uphold the 
manufacturer's motion for summary judgment.13
Rather than exclusively examining the purchaser's level of knowledge, 
as the Haase court did, the Mohr court 
focused on the manufacturer's level of knowledge about the purchaser. 
Mohr explicitly stated that "the issue under Restatement 
(Second) of Torts § 388(b), correctly framed, is whether KDI 
had reason to believe that the high school had knowledge the 
platforms were likely to be dangerous if used in less than five feet of 
water."14 The court of appeals explained 
that while the purchaser's "actual knowledge is not dispositive under 
§ 388(b)," it is "relevant if KDI knew of it or if the knowledge of 
this high school may be reasonably inferred to be the knowledge of high 
schools in general who purchase the product...."15
The Future Application of the Doctrine in Wisconsin
In Mohr, the Wisconsin Court of Appeals clearly centered the 
spotlight of the sophisticated user inquiry on the manufacturer's level 
of knowledge. What remains unclear is what level of knowledge a 
manufacturer must possess in order to be granted refuge under the 
doctrine. It is not known whether a manufacturer is protected if it knew 
that the purchaser's industry had knowledge about a hazard, or if a 
manufacturer must be aware that the specific purchaser knew of the 
hazard. How future courts interpret the level of knowledge required by 
manufacturers for protection under the doctrine will likely determine 
the potency of this defense in Wisconsin.
Future judicial consideration of at least two other issues also will 
affect the ultimate scope of this doctrine in Wisconsin. To date the 
Wisconsin Court of Appeals has only applied this doctrine to warnings 
claims rooted in negligence, failing to move further because the courts 
in Haase and Mohr only addressed claims rooted in 
negligence.16 Other states that have 
adopted the doctrine have blurred any distinction between a warnings 
claim based in negligence and a warnings claim based in strict 
liability.17 There is reason to believe 
that Wisconsin courts will apply the sophisticated user doctrine to both 
types of warnings claims. The court of appeals in Mohr 
explicitly refused to further expand the scope of this doctrine without 
guidance from the Wisconsin Supreme Court; however, it questioned 
outright whether there was any "practical significance" between a strict 
liability warnings claim and a warnings claim rooted in 
negligence.18 This stance is consistent 
with the court of appeals' previous statement that the proof 
requirements for warnings claims in negligence and in strict liability 
are essentially the same.19
Additionally, future courts may be asked to consider the policy 
argument that the sophisticated user doctrine burdens employees with 
bearing too great a share of the costs of their injuries. Plaintiffs' 
attorneys are concerned that adopting this doctrine will unjustly 
foreclose an avenue of recovery for innocently injured plaintiffs. The 
Wisconsin Court of Appeals explained that the adoption of the doctrine 
"places the duty to warn on the party arguably in the best position to 
ensure workplace safety, the purchaser-employer."20 However, the doctrine effectively allows a 
manufacturer to transfer responsibility and liability to employers for 
warning workers who ultimately use a manufacturer's product. While in 
some states this shift of liability may not affect a worker's ability to 
pursue an action against the employer, Wisconsin has strict civil 
immunity for employers under its worker's compensation laws. If the 
sophisticated user doctrine allows the transfer of liability to the 
employer, and the employer is protected by worker's compensation 
immunity, the injured employee will be left with only the limited 
recovery available through worker's compensation.
National Trend
Over the last two decades a number of states have incorporated the 
sophisticated user doctrine into law as a protection for manufacturers, 
with few states rejecting the doctrine outright.21 Wisconsin is one of several states to recently 
consider adopting this doctrine. In the most recent decision in which a 
state court adopted the doctrine, the Texas Supreme Court set out a 
series of factors for its courts to consider when determining whether 
the manufacturer bears a duty to warn.22 
The Minnesota Court of Appeals, relying on the same case that the 
Haase court relied on, invoked the doctrine to dismiss a claim 
against the same silica sand supplier that was sued in 
Haase.23 However, the Minnesota 
Supreme Court recently overruled the decision, finding an insufficiency 
of evidence on key issues.24 In doing so, 
the court distinguished between what it termed a sophisticated user 
defense and a sophisticated intermediary defense.25 The court acknowledged that a manufacturer has 
no duty to warn under a sophisticated user defense when the actual user 
is as knowledgeable about the product and its dangers as is the 
manufacturer.26 In contrast, the court 
refused to decide whether it would relieve a manufacturer of its duty 
when the product's purchaser (the sophisticated intermediary) is as 
knowledgeable as the manufacturer but the actual user may not be 
knowledgeable.27
Conclusion
The adoption of the sophisticated user doctrine in Wisconsin is in 
itself a boon for manufacturers who are plagued with claims that they 
inadequately warned of the dangers posed by their products. The doctrine 
likely will be expanded to apply to strict liability claims. However, 
future interpretation of how this doctrine will be applied in Wisconsin 
may serve to limit its use. Under Mohr, whether the doctrine 
applies in a particular case turns on the manufacturer's level of 
knowledge about the purchaser and the purchaser's industry. Questions 
remain about how much a manufacturer must know before it is relieved of 
a responsibility to warn. Must the manufacturer know that the purchaser 
is aware of the general dangers posed by the product, or must the 
manufacturer know that the purchaser is aware of dangers associated with 
the purchaser's specific use of the product? Alternatively, perhaps it 
is sufficient that a manufacturer know that a purchaser is an active 
member of a knowledgeable professional or industry group. Courts' 
guidance on these issues will provide counsel with a better 
understanding of the potency of the sophisticated user defense and its 
effect on the landscape of failure to warn claims in Wisconsin.
Endnotes
12004 WI 97, 274 Wis. 2d 143, 682 
N.W.2d 389, affirming 2003 WI App 192, 266 Wis. 2d 970, 669 
N.W.2d 737 (adopting and applying rationale of Bergfeld v. Unimin 
Corp., 319 F.3d 850 (8th Cir. 2003)).
2Haase, 2003 WI App 192, 
¶ 21, 266 Wis. 2d 970.
3Strasser v. Transtech Mobile 
Fleet Serv. Inc., 2000 WI 87, ¶ 58, 236 Wis. 2d 435, 613 
N.W.2d 142.
4Bergfeld v. Unimin Corp., 
319 F.3d 350, 353 (8th Cir. 2003).
5Haase, 2003 WI App 192, 
¶ 21, 266 Wis. 2d 970. Wisconsin courts have previously recognized 
that "there is no duty to warn members of a trade or profession about 
dangers generally known to the trade or profession." Shawver v. 
Roberts Corp., 90 Wis. 2d 672, 686, 280 N.W.2d 226 (1979). However, 
the Shawver court did not refer to this principle as the 
sophisticated user doctrine.
6Haase, 2003 WI App 192, ¶ 1, 
266 Wis. 2d 970.
7Id. ¶ 3.
8Id. ¶ 1.
9Id.
10Mohr v. St. Paul Fire & 
Marine Ins. Co., 2004 WI App 5, 269 Wis. 2d 302, 674 N.W.2d 
576.
11Id. ¶ 6.
12Id. ¶ 14.
13Id. ¶ 21.
14Id. ¶ 20.
15Id.
16Id. ¶ 34.
17See, e.g., Phillips v. A.P. 
Green Refractories Co., 630 A.2d 874 (Pa. Super. Ct. 1993), 
aff'd sub nom. Phillips v. A-Best Prods. Co., 665 A.2d 1167 
(Pa. 1994); Donahue v. Phillips Petroleum Co., 866 F.2d 1008 
(8th Cir. 1989) (applying Missouri law).
18Mohr, 2004 WI App 5, 
¶ 32 n.10, 269 Wis. 2d 302; see also Nigh v. Dow Chemical 
Co., 634 F. Supp. 1513, 1517 (W.D. Wis. 1986) ("The Court will 
leave the task of distinguishing between negligence and strict liability 
in the duty to warn to those who count angels on the heads of 
pins.").
19Mohr, 2004 WI App 5, 
¶ 32 n.10, 269 Wis. 2d 302. (citing Tanner v. Shoupe, 228 
Wis. 2d 357, 365 n.3, 596 N.W.2d 805 (Ct. App. 1999); Krueger v. 
Tappan Co., 104 Wis. 2d 199, 207 n.3, 311 N.W.2d 219 (Ct. App. 
1981)).
20Haase, 2003 WI App 
192, ¶ 21, 266 Wis. 2d 970; contrast with Gray v. Badger Mining 
Corp., 664 N.W.2d 881, 885 (Minn. Ct. App. 2003) ("in the 
industrial setting ... the employer is not motivated to warn 
employees because the employer's liability is limited by the worker's 
compensation laws."), rev'd, 676 N.W.2d 268 (Minn. 2004), 
and Humble Sand & Gravel Inc. v. Gomez, 146 S.W.3d 170, 
184-85 (Tex. 2004) ("disregard [by employers] of the risks to their 
employees of inhaling silica dust was not for want of additional 
information that flint suppliers should have furnished, but for want of 
care.").
21See Phillips v. A.P. Green 
Refractories Co., 630 A.2d 874 (Pa. Super. Ct. 1993), 
aff'd, 665 A.2d 1167 (Pa. 1994); Jodway v. Kennametal 
Inc., 525 N.W.2d 883 (Mich. Ct. App. 1994); Groll v. Shell Oil 
Co., 196 Cal. Rptr. 2d 52, 54 (Cal. Ct. App. 1983); Smith v. 
Walter C. Best Inc., 927 F.2d 736, 741 (3d Cir. 1990); Goodbar 
v. Whitehead Bros., 591 F. Supp. 552, 561 (W.D. Va. 1984), 
aff'd sub nom. Beale v. Hardy, 769 F.2d 213 (4th Cir. 1985); 
Damond v. Avondale Indus. Inc., 718 So. 2d 551, (La. Ct. App. 
1998), writ denied, 735 So. 2d 637 (La. Ct. App. 1999). But 
see Sharp v. Wyatt Inc., 627 A.2d 1347 (Conn. App. Ct. 1993) 
(sophisticated user doctrine is not affirmative defense but rather part 
of user awareness issue to be considered by trier of fact).
22Humble Sand & Gravel 
Inc., 146 S.W.3d at 192-94. Those factors, applied to a situation 
involving abrasive blasting, are: 1) the likelihood of serious injury 
from a supplier's failure to warn; 2) the burden on a supplier of giving 
a warning; 3) the feasibility and effectiveness of a supplier's warning; 
4) the reliability of operators to warn their own employees; 5) the 
existence and efficacy of other protections; and 6) the social utility 
of requiring, or not requiring, suppliers to warn. Id.
23Gray, 664 N.W.2d at 
887.
24Gray v. Badger Mining 
Corp., 676 N.W.2d 268, 277 (Minn. 2004).
25Id. at 276-77.
26Id.
27Id. at 277.
28See Moore ex. rel. Moore v. 
Memorial Hosp. of Gulfport, 825 So. 2d 658, 664-65 (Miss. 2002) 
(listing states that have adopted learned intermediary doctrine). 
See also Kevin L. Colbert & John Gray, Recent 
Developments in Toxic Tort and Environmental Litigation, 38 Tort 
Trial & Ins. Prac. L.J. 691 (Winter 2003).
29Vitanza v. The Upjohn 
Co., 778 A.2d 829, 844-47 (Conn. 2001).
30Kurer v. Parke, Davis & 
Co., 2004 WI App 74, 274 Wis. 2d 390, 679 N.W.2d 867.
31Id. ¶ 31 n.7.
Wisconsin Lawyer