## Facts

- John Potter and other Electric Boat shipyard employees worked as “grinders,” using defendants’ pneumatic hand tools for many years, often for about twenty-five years.
- Plaintiffs alleged prolonged exposure to tool vibration caused permanent vascular and neurological injuries in their hands consistent with hand-arm vibration syndrome.
- Reported symptoms included finger blanching, pain, numbness, tingling, reduced grip strength, intolerance to cold, and clumsiness associated with restricted blood flow.
- An industrial hygienist tested tools at the worksite and found many exceeded vibration exposure limits set by ANSI and threshold limits set by the American Conference of Governmental and Industrial Hygienists.
- Plaintiffs sued the manufacturers under strict products liability, alleging defective design due to excessive vibration and failure to provide adequate warnings about vibration risks.
- Electric Boat intervened to seek reimbursement of workers’ compensation payments.

## Issues

1. Whether a design-defect plaintiff must prove a feasible alternative design as part of the prima facie case, or whether defectiveness may be determined by ordinary consumer expectations.
2. How defectiveness should be evaluated for complex product designs where ordinary consumers may lack clear safety expectations.
3. Whether the trial court’s alteration/modification instruction improperly shifted to defendants the burden concerning substantial change in the product’s condition.
4. Whether the evidence and jury instructions (including treatment of “state of the art”) were sufficient and legally proper.

## Decision

- The Supreme Court of Connecticut affirmed in part and reversed in part.
- The court held a feasible alternative design is not a mandatory element of a design-defect prima facie case under Connecticut products liability law.
- The court adopted a consumer-expectation standard as the core design-defect test, with additional risk-utility considerations available in cases involving complex designs.
- The court found sufficient evidence to support the jury’s design-defect findings under the consumer-expectation framework despite no proof of a specific alternative design.
- The court held the trial court erred by instructing on alteration/modification in a way that shifted to defendants the burden to disprove that the product reached users without substantial change.
- The court ordered corrective relief consistent with these instructional errors.

## Legal Principles

- A product is defectively designed if it is more dangerous than an ordinary consumer would expect, given ordinary community knowledge about the product’s characteristics.
- Proof of a feasible alternative design is not required in every design-defect case; it may be relevant evidence but is not a per se prerequisite to reach the jury.
- For complex product designs where consumer safety expectations may be indeterminate, the factfinder may consider risk-utility type factors, including:
  - the product’s usefulness;
  - the likelihood and severity of harm from the design;
  - the feasibility and cost of safer alternative designs;
  - the ability to reduce danger without impairing utility or making the product excessively expensive; and
  - the feasibility of spreading loss through pricing.
- In strict liability, the plaintiff bears the burden to prove the product reached the user without substantial change in condition; jury instructions may not reallocate that burden to defendants through alteration/modification formulations.
- Evidence bearing on technological feasibility and related “state of the art” considerations may be relevant to design-defect evaluation, but does not create a categorical bar to recovery in the absence of proof of a better design.

## Conclusion

The court rejected a rigid alternative-design requirement for design-defect claims, retained consumer expectations as the primary standard, permitted risk-utility factor analysis for complex designs, and reversed in part because the alteration/modification instruction improperly shifted the plaintiff’s burden regarding substantial change.


Potter v. Chi. Pneumatic Tool Co., 241 Conn. 199, 694 A.2d 1319 (Conn. 1997)