## Facts

- Wallace C. Halverson worked as a plumber from 1948 until 1979 and was repeatedly exposed to asbestos at each place of employment.
- From 1948 through 1960, Halverson worked for multiple plumbing and heating employers (including A. G. O’Brien Plumbing & Heating Co. (O’Brien)) and encountered asbestos insulation and dust.
- From 1962 to 1970, Halverson worked solely for Sher Plumbing & Heating and experienced daily asbestos exposure.
- From 1970 to 1975, Halverson worked solely for Larrivy Plumbing & Heating Co. (Larrivy).
- From 1976 to February 1977, Halverson worked for both Larrivy and O’Brien on separate projects and was exposed to asbestos at each job site.
- From February 1977 to September 1977, Halverson worked only for O’Brien.
- From September 1977 to January 1978, Halverson did not work; he then returned to work for O’Brien (at reduced capacity) until May or June 1979, when he quit working completely.
- In 1975, Halverson first noticed breathing trouble while swimming; an X-ray taken that year showed signs consistent with asbestosis, but he was not formally diagnosed then.
- In August 1977, Halverson sought medical care for shortness of breath, reporting symptoms over the prior two years.
- In September 1977, Dr. Terrance Clark, a pulmonary specialist, diagnosed Halverson with asbestosis.
- At a 1980 workers’ compensation hearing, Dr. Clark testified that Halverson’s asbestosis resulted from asbestos exposure from 1952 to August 1977, but clarified that asbestosis has a latency period of roughly 5 to 40 years; accordingly, Halverson’s then-present symptoms were attributable to exposures occurring at least five years earlier (1975 or before). Dr. Clark also testified that exposures after 1975 might contribute to the disease later.
- The compensation judge found Halverson had a 40% permanent partial disability due to asbestosis and imposed liability on O’Brien under a “last exposure” theory.
- The Workers’ Compensation Court of Appeals (WCCA) vacated that allocation and held Larrivy liable because Halverson’s compensable disease, as shown by the medical testimony and symptom timing, was tied to exposures during Larrivy’s employment period (including 1975), while O’Brien’s later exposure was not a substantial contributing factor to the disability being compensated.
- Larrivy sought review in the Minnesota Supreme Court.

## Issues

1. Whether the record supported the WCCA’s finding that Larrivy (the second-to-last employer) was liable for the full workers’ compensation award because Halverson’s asbestos exposure while working for O’Brien (the last employer) was not a substantial contributing factor to the disability at issue.

## Decision

- The Minnesota Supreme Court affirmed the WCCA.
- The Court held that the “last employer” rule does not impose liability on the last employer in time unless there is a causal connection between that employment and the occupational disease/disability.
- Based on Dr. Clark’s latency testimony and the timing of Halverson’s symptoms, the Court concluded the record supported the WCCA’s determination that Halverson’s post-1975 exposure at O’Brien was not a substantial contributing factor to the existing disability.
- The Court therefore left full liability with Larrivy and did not apportion liability among employers.

## Legal Principles

- In Minnesota occupational disease cases, liability generally falls on the employer and insurer on the risk when the employee becomes disabled.
- An employer is not liable merely because it is the last employer in time; there must be a causal connection between the work for that employer and the occupational disease, commonly framed as whether the employment was a substantial contributing factor to the disability.
- Apportionment among multiple employers is permitted only in rare cases where medical evidence allows a reasonably precise allocation of causation.
- On review, the Supreme Court will sustain the WCCA’s factual determinations when supported by evidence in the record, including credited medical testimony.

## Conclusion

The Minnesota Supreme Court upheld the WCCA’s reassignment of liability from the last employer, O’Brien, to the earlier employer, Larrivy, because the medical evidence supported a finding that exposures after 1975 could contribute only later and were not a substantial contributing factor to Halverson’s then-compensable asbestosis disability, making Larrivy responsible for the full award.


Halverson v. Larrivy Plumbing & Heating Co., 322 N.W.2d 203 (1982)