The term “trigger of coverage” means “what event must occur for potential coverage to commence under the terms of the insurance policy” and “what must take place within the policy’s effective dates for the potential of coverage to be ‘triggered.’“ [In Re Feature Realty Litig., 468 F. Supp.2d 1287, 1295, n.2 (E.D. Wash. 2006)]
After the California Supreme Court adopted a continuous trigger in Montrose Chemical Corp. v. Admiral Ins. Co. (1995) 10 Cal.4th 645, 685, 42 Cal.Rptr.2d 324, 913 P.2d 878 (Montrose) in the case of successive policies, property damage that is continuous or progressively deteriorating throughout several policy periods is potentially covered by all policies in effect during those periods, so that the insurer’s duty to defend arose under those policies. Insurers, trying to limit their coverage, revised the policy wording.
Therefore, the precise question is what result follows under the language of the policies of insurance to which the parties agreed. The “continuous injury” trigger has been applied mostly in cases involving gradual release of pollutants and other environmental harms. After Montrose, the insurer revised its policies to use the language for the very purpose of “obviat[ing] the application of the ‘progressive damage-continuous trigger’ articulated in Montrose.” As a result, the defendant’s policies state that property damage “which commenced prior to the effective date of this insurance will be deemed to have happened in its entirety prior to, and not during, the term of this insurance.” [Ins. Co. of Pa. v. Am. Safety Indem. Co., 32 Cal.App.5th 898, 244 Cal.Rptr.3d 310 (Cal. App., 2019)]