The Eighth Circuit has sided with an insurer, ruling that a pollution exclusion clause bars coverage for carbon monoxide injuries from a portable heater.
The decision, handed down on April 7, 2026, came in a case between North Star Mutual Insurance Company and two North Dakota farm operators, Lyle and Darin Rodin. At issue was whether the insurer owed a duty to defend or indemnify the Rodins after Larry Alber, who alleged he was injured while working on their farm, claimed that a portable heater in their farm shop emitted dangerous levels of carbon monoxide and caused him life-altering cardiovascular and neurological injuries.
North Star had issued the Rodins a liability policy covering bodily injuries sustained on their property. But the policy also contained a pollution exclusion – a provision that barred coverage for bodily injury or property damage resulting from the actual, alleged, or threatened discharge, dispersal, seepage, migration, spill, release, or escape of pollutants. The policy defined a pollutant as any solid, liquid, gaseous, thermal, or radioactive irritant or contaminant, and included acids, alkalis, chemicals, fumes, smoke, soot, vapor, and waste in that definition.
About a month after Alber sued the Rodins, North Star filed a declaratory judgment action, arguing that carbon monoxide fell within the policy's definition of a pollutant and that the exclusion applied. The district court agreed, granting summary judgment in North Star's favor.
On appeal, the Rodins made two arguments. They asked the court to send the question to the North Dakota Supreme Court, which had never interpreted a pollution exclusion provision. They also argued that the exclusion was never meant to cover something like carbon monoxide emitted from a heater in a farm shop.
The Eighth Circuit was not persuaded on either front.
On the certification request, the court noted that the Rodins had waited until after losing at the district court level to raise the idea, and had never raised it before the lower court at all. The court found that North Dakota had provided enough guidance on how to interpret insurance contracts to allow federal courts to reach a determination without certification.
On the merits, the court walked through the two main schools of thought on pollution exclusions. Some courts read them narrowly, treating them as applying only to traditional environmental pollution events. Others treat them as absolute exclusions that apply whenever a substance meeting the policy definition of pollutant causes injury through the specified means. The outcome often depends on which state's law applies.
Applying North Dakota law, the Eighth Circuit followed the absolute approach. The court pointed out that North Dakota does not apply the reasonable expectation doctrine when interpreting insurance policies, which removed one of the key tools courts in other states have used to limit pollution exclusions. Instead, the court relied on plain-language dictionary definitions. Carbon monoxide is gaseous. A contaminant is something that makes something unfit for use by introducing unwholesome or undesirable elements. The court found that carbon monoxide, particularly at high levels, can render air unfit for use, and therefore met the policy's definition of a pollutant without ambiguity.
The Rodins raised a few additional arguments. They suggested that the court's reading made a separate lead exclusion in the policy unnecessary, since lead would already be caught by the pollution exclusion. The court disagreed, noting that the pollution exclusion only applies to injuries from the discharge, dispersal, seepage, migration, spill, release, or escape of a pollutant, while the lead exclusion covers injuries from lead exposure through any means, including ingestion, inhalation, or absorption.
The Rodins also warned that the interpretation could lead to absurd results, with virtually any harmful substance being classified as a pollutant. The court acknowledged the concern but noted that the exclusion is not limitless – it only applies when injury results from a specific set of listed events. If a substance causes harm in a way not covered by those terms, the exclusion does not kick in.
The case is worth watching for insurance professionals because it adds to a growing body of appellate authority supporting the broad enforceability of pollution exclusion clauses, even in scenarios far removed from what most people think of as pollution. A portable heater in a farm shop is not an industrial discharge or a chemical spill, but the policy language, as written, does not draw that distinction – and the Eighth Circuit held that courts applying North Dakota law should not draw it either.
