## Facts

- Frank Halloran, an automobile mechanic, was injured when a can of refrigerant (Freon) exploded while he was servicing an automobile air-conditioning system.
- The refrigerant was packaged and sold by Virginia Chemicals, Inc., and distributed by A & E Auto Glass & Service Corporation.
- Halloran testified that he heated the can only by placing it in warm tap water, which he described as his customary safe method.
- The can’s label warned against heating beyond a stated temperature and against certain heating methods, including immersion heating coils.
- Virginia Chemicals sought to introduce coworker testimony that Halloran repeatedly and routinely used an immersion heating coil to heat refrigerant cans during similar work, despite the warnings.
- The trial court excluded the coworker testimony as impermissible evidence of prior carelessness to prove negligence on the occasion in question.
- A jury found for Halloran on liability; the Appellate Division affirmed, over dissent, and the case reached the Court of Appeals on a certified question.

## Issues

1. Whether a products-liability plaintiff must identify a specific defect to establish a prima facie case when the product fails during intended use and other causes are excluded.
2. Whether evidence of a person’s repeated practice of using an immersion heating coil is admissible as habit evidence to show likely conduct on the day of the accident.

## Decision

- The Court of Appeals held that a plaintiff need not prove a specific, identifiable defect if the evidence permits an inference that the product did not perform as intended and other causes not attributable to the defendant are excluded.
- The Court held that testimony about Halloran’s regular, repeated use of an immersion heating coil was admissible as habit (routine practice), not inadmissible character or propensity evidence.
- The Court reversed the Appellate Division and ordered a new trial because excluding the habit evidence was prejudicial to the central liability dispute.

## Legal Principles

- A defect in a product or its packaging may be inferred from circumstantial evidence when the product malfunctions during intended use and nondefendant causes are reasonably excluded.
- Habit evidence concerns a deliberate, repetitive, and regular response to a specific, recurring situation and may be used to show conduct on a particular occasion conformed to that habit.
- Prior conduct offered only to show general carelessness or propensity is character evidence and is generally inadmissible to prove conduct on a specific occasion.
- The proponent of habit evidence must show sufficient regularity, frequency, and situational specificity to support an inference of consistent conduct.
- Erroneous exclusion of admissible habit evidence warrants a new trial when it bears directly on a central disputed issue and affects the jury’s evaluation of fault and credibility.

## Conclusion

The Court of Appeals ordered a new trial, holding that defect may be proven by inference without pinpointing a specific flaw, and that evidence of a consistent, repeated practice in a specific work context is admissible as habit evidence to prove likely conduct on the day of an accident.


Halloran v. Virginia Chems., Inc., 41 N.Y.2d 386 (N.Y. 1977)