Coffman Does Not Create a Per Se Bar to Failure-to-Warn Claims Involving Combined Use of Two Sound Products

1. Introduction

In Sarah Elizabeth Woodruff ex rel. Ethan Woodruff v. Ford Motor Company (the “Dorel” companion appeal), the Supreme Court of Tennessee revisited the reach of its 2021 decision in Coffman v. Armstrong International, Inc., 615 S.W.3d 888 (Tenn. 2021) in the context of failure-to-warn claims under the Tennessee Products Liability Act (TPLA).

The case arose from a catastrophic Knoxville automobile collision in which six-year-old Ethan Woodruff sustained severe injuries. Ethan was seated in a Dorel “Pronto” high-backed booster seat and was restrained using a Ford seatbelt extender that had been purchased aftermarket. The plaintiff (Ethan’s mother, Sarah Woodruff) alleged that Dorel’s booster-seat manual effectively encouraged use of a seatbelt extender (“contact your vehicle dealer for a seat belt extender” if the belt is too short) without adequate warnings, despite the risk that extenders could undermine restraint performance when used with child seats.

The legal issue presented on Tennessee Rule of Appellate Procedure 11 review was narrow but consequential: whether Coffman defeats, as a matter of law, a failure-to-warn claim against a manufacturer when the alleged danger arises from using the manufacturer’s product in combination with another manufacturer’s product.

2. Summary of the Opinion

The Court reversed the Court of Appeals and held that Coffman does not mandate dismissal as a matter of law of the plaintiff’s failure-to-warn claim against Dorel. The Court clarified that Coffman’s holding is limited to its factual setting—post-sale integration of asbestos-containing materials manufactured and sold by others into otherwise non-asbestos equipment—and should not be read as a bright-line rule barring all failure-to-warn claims whenever another manufacturer’s product is involved.

Importantly, the Court did not decide that Dorel owed a duty to warn on these facts. It held only that Coffman is not dispositive, and remanded for the Court of Appeals to address issues it had pretermitted (such as abnormal use and proximate cause).

3. Analysis

3.1. Precedents Cited

Coffman v. Armstrong International, Inc., 615 S.W.3d 888 (Tenn. 2021)

Role in this case: Coffman was the central authority relied upon by Dorel and the Court of Appeals to argue that manufacturers have “no duty to warn with respect to products manufactured and sold by others.” The Supreme Court rejected that broad reading.

How it influenced (and limited) the Court’s decision: The Woodruff Court treated Coffman as a case about post-sale integration of a hazardous third-party product (asbestos-containing materials) into a defendant’s otherwise non-defective product, producing an “end-product” that the defendant did not make or sell. Coffman interpreted TPLA language tying liability to whether “the product” was defective or unreasonably dangerous when it left the defendant’s control, and emphasized that statutory terms like “it” refer to the defendant’s own product.

The Woodruff Court took Coffman’s own caveats seriously—Coffman repeatedly stated it dealt “strictly” with post-sale integration of asbestos parts manufactured and sold by others—and held that Coffman does not automatically govern a different combined-use scenario: two independently sound end-products used together, where the alleged defect is an inadequate warning about a foreseeable misuse involving that combined use.

Rye v. Women’s Care Ctr. of Memphis, MPLLC, 477 S.W.3d 235 (Tenn. 2015)

Role: Provided the standard of review for summary judgment (de novo, no presumption of correctness). While not substantive products-liability guidance, Rye frames the appellate posture: the Court was evaluating whether summary judgment was proper based on an asserted legal bar, not weighing disputed facts.

Davis v. Komatsu Am. Indus. Corp., 42 S.W.3d 34 (Tenn. 2001)

Role: The Court used Davis as an example that TPLA duty/liability questions can differ materially by product configuration: component-part liability for a defective final integrated product is a distinct doctrinal space from Coffman’s post-sale integration scenario.

How it influenced reasoning: The Woodruff Court rejected Dorel’s attempt to use Davis to support a broad “no duty to anticipate combinations” rule. Davis addressed component-part principles (including Restatement (Third) of Torts: Products Liability § 5) and did not resolve the combined-use warnings issue presented here.

Out-of-jurisdiction “combined product” authorities used as comparative context

The Court cited several decisions to illustrate that jurisdictions distinguish among categories of combined-product cases, including:

  • O'Neil v. Crane Co., 266 P.3d 987 (Cal. 2012) (no duty for post-sale asbestos integration; distinguished scenarios where two sound products together create danger).
  • Tellez-Cordova v. Campbell-Hausfeld/Scott Fetzger Co., 28 Cal. Rptr. 3d 744 (Cal. Ct. App. 2004) (example of liability reasoning where two sound products’ combined use creates danger).
  • Rastelli v. Goodyear Tire & Rubber Co., 591 N.E.2d 222 (N.Y. 1992) (discussed the concept that some cases involve two sound products whose combination creates danger, though it found no duty on its facts).
  • Ilosky v. Michelin Tire Corp., 307 S.E.2d 603 (W. Va. 1983) (cited within Rastelli; used to illustrate the “two sound products” framing).
  • Macias v. Saberhagen Holdings, 282 P.3d 1069 (Wash. 2012) and Braaten v. Saberhagen Holdings, 198 P.3d 493 (Wash. 2008) (discussed recognized exceptions where two sound products together create an unreasonably unsafe condition and may support a duty to warn).

Why these mattered: The Court did not adopt these jurisdictions’ tests, but used them to validate a core point: “combined use” is not monolithic, and Coffman’s asbestos-integration rule cannot simply be pasted onto a different combined-use fact pattern.

Authorities referenced in connection with foreseeability/misuse concepts

  • Goins v. Clorox Co., 926 F.2d 559 (6th Cir. 1991) (applying Tennessee law; discussed in the opinion as part of the plaintiff’s foreseeability/misuse framing).

3.2. Legal Reasoning

The Court’s reasoning is best understood as a scope-and-category clarification rather than a full-duty holding. It proceeds in four moves:

  1. Identify the precise Coffman question and holding. Coffman decided whether equipment manufacturers had a duty to warn about dangers associated with post-sale integration of asbestos-containing materials made and sold by others.
  2. Compare Coffman’s product configuration to this case’s configuration. Coffman involved turning a sound product into an asbestos-exposure hazard by adding a third-party hazardous material later. Here, by contrast, the allegation is that two independently sound end-products (a booster seat and a seatbelt extender) used together create a danger that is not present when either is used alone as intended.
  3. Return to the TPLA text without overreading Coffman. The Court emphasized the TPLA’s focus on whether the defendant’s product is defective/unreasonably dangerous when it leaves the defendant’s control (Tenn. Code Ann. § 29-28-105(a)) and on whether the product is unsafe for “normal or anticipatable handling” (Tenn. Code Ann. § 29-28-102(2)), as well as the carve-out for “subsequent unforeseeable alteration…or abnormal use” (Tenn. Code Ann. § 29-28-108). The key point: nothing in Coffman or the TPLA text creates a categorical exemption whenever a foreseeable misuse involves another manufacturer’s product.
  4. Limit the Court’s own holding to the Rule 11 issue. The Court repeatedly states what it is not deciding: whether Dorel in fact owed a duty on these facts, whether warnings were adequate, whether Nissan’s manual breaks causation, and other merits questions. It holds only that summary judgment cannot be affirmed solely on the premise that Coffman bars the claim as a matter of law.

3.3. Impact

This decision materially narrows the way litigants may deploy Coffman at the pleading/summary judgment stage. Its practical impacts likely include:

  • No automatic Coffman dismissal in “combined use” warning cases. Defendants cannot treat Coffman as a universal rule that ends any case involving another manufacturer’s product. Courts must examine the product configuration (post-sale integration of a hazardous item vs. combined use of sound products vs. component parts vs. replacements).
  • Renewed importance of “anticipatable handling” and foreseeability under TPLA text. The opinion signals that claims framed as foreseeable misuse of the defendant’s own product may remain viable even when the misuse involves another product. Whether the misuse is “anticipatable” and whether later use is “unforeseeable” under § 29-28-108 become fact- and context-sensitive battlegrounds.
  • More litigation on duty and causation rather than categorical bars. On remand, defendants will likely press alternative defenses (abnormal use, proximate cause, warning adequacy, superseding cause, reliance on vehicle-manual warnings). The Supreme Court’s restraint—remanding without deciding duty—invites development of a Tennessee-specific framework through future appellate decisions.

4. Complex Concepts Simplified

Failure to warn (under the TPLA)

A “failure to warn” claim alleges that a product is defective or unreasonably dangerous because the manufacturer/seller did not provide adequate warnings or instructions about risks of use (including, in some circumstances, foreseeable misuse). Under the TPLA, liability is tied to the condition of the product when it left the defendant’s control.

“Defective condition” and “unreasonably dangerous”

  • Defective condition (Tenn. Code Ann. § 29-28-102(2)): the product is unsafe for “normal or anticipatable handling and consumption.” “Anticipatable” is key—it leaves room for risks that arise from predictable real-world use, not just idealized intended use.
  • Unreasonably dangerous (Tenn. Code Ann. § 29-28-102(8)): dangerous beyond what an ordinary consumer would expect, or so dangerous that a prudent manufacturer would not market it assuming knowledge of the danger.

“Post-sale integration” vs. “combined use”

  • Post-sale integration (Coffman): after the defendant sells its product, someone later adds a different product (e.g., asbestos materials), creating a new hazardous end-product. Coffman held the defendant equipment makers were not responsible for warning about hazards from those later-added third-party products.
  • Combined use of two sound products (this case): each product is generally safe for its intended use, but using them together may create a new risk. The Court held Coffman does not automatically resolve whether a duty to warn exists in that different setting.

Summary judgment

Summary judgment ends a case without trial only when there is no genuine dispute of material fact and the moving party is entitled to judgment as a matter of law. The Supreme Court held Dorel was not entitled to summary judgment solely based on Coffman.

5. Conclusion

The Supreme Court of Tennessee’s core clarification is doctrinally significant: Coffman is not a broad “no duty” rule for any case involving another manufacturer’s product. Coffman addresses a particular category—post-sale integration of hazardous third-party products—and does not mandate dismissal of failure-to-warn claims alleging that a manufacturer failed to warn about foreseeable combined use or misuse that renders its own product unsafe.

By reversing the Court of Appeals and remanding, the Court reopened the analytical space for Tennessee courts to evaluate combined-use warning claims under the TPLA’s text (including “anticipatable handling” and the “unforeseeable…abnormal use” limitation) rather than treating Coffman as a categorical bar.