Last injurious exposure rule is a judicially-created doctrine whereby full liability for an occupational disease resulting from the claimant's exposure to injurious stimuli during more than one period of employment or insurance coverage is assigned to a single employer or insurer. Therefore according to this rule, liability for an occupational injury or illness falls to the employer that exposed the worker to the injurious substance just before the first onset of the disease or injury. Last injurious exposure rule is also known as last employer rule.
The following is an example of a case law on last injurious exposure rule:
Under the "last injurious exposure rule," any exposure to harmful stimuli during an insurer's coverage period will lead to liability if the employee becomes disabled during that period by an exposure-caused injury, even if the most recent exposure was not the primary or triggering cause for the disability. [Bath Iron Works Corp. v. Dir., OWCP, 244 F.3d 222, 228-229 (1st Cir. Mass. 2001)]