The Sudden and Accidental Exception to the Contamination and Pollution Exclusion

In 1970 the ISO introduced the contamination and pollution exclusion, which became universal on primary and excess liability policies. When policyholders ran out of coverage on pre-1970 policies or needed coverage for post-1970 pollution losses which were gradual in nature, the sudden and accidental limitation came under attack in litigation trying to circumvent insurers’ claim denials.

I was involved in the introduction of this exclusion and know firsthand what coverage existed under policies with such exclusions. So far I have been involved in several environmental cases and can opine on what brokers were explaining to clients on what losses were or were not covered under liability policies with contamination and pollution exclusions.