Liability insurance exception for pollution coverage that is not both sudden and accidental from the insured's standpoint. As a result of the damage suits from such incidents as the chemical pollution at Love Canal, insurance companies began to modify pollution coverage in their liability policies in the 1970s. First, companies changed coverage to apply only if pollution was "sudden and accidental," rather than "gradual." But some courts ruled that "sudden and accidental" could encompass several years of pollution problems. Consequently, the insurance services office (ISO) introduced a new comprehensive general liability insurance (CGL) policy in 1985 (replaced today by the commercial general liability form) that excluded coverage for nearly all types of pollution damage, leaving only limited liability coverage for pollution originating away from an insured's premises.