Legal Definitions - last-injurious-exposure rule

The last-injurious-exposure rule is a principle primarily applied in workers' compensation cases, especially when an employee develops an occupational disease or a cumulative trauma injury over time due to exposure to harmful conditions or repetitive stress across multiple employers.

Under this rule, the employer who last exposed the worker to the injurious conditions is typically held responsible for providing workers' compensation benefits. This applies even if previous employers also contributed to the development of the disease or injury. The key is that the final exposure must have been "injurious," meaning it contributed, even minimally, to the worker's condition.

Here are some examples illustrating this rule:

• Example 1: Occupational Lung Disease

  Maria worked for a chemical manufacturing plant, "ChemCorp," for 15 years, where she was regularly exposed to various industrial solvents. She then moved to "PureChem Solutions" for 5 years, where she continued to work with similar chemicals. Shortly after leaving PureChem Solutions, she was diagnosed with a severe occupational lung disease directly linked to solvent exposure. Even though ChemCorp was her employer for a longer period and likely contributed significantly to her exposure, the last-injurious-exposure rule would likely hold PureChem Solutions responsible for her workers' compensation claim because they were her last employer to expose her to the harmful solvents that contributed to her condition.

• Example 2: Cumulative Hearing Loss

  David was a heavy equipment operator for 30 years. He worked for "MegaConstruction Inc." for 18 years, then for "Urban Builders LLC" for 10 years, and finally for "Rapid Excavation Co." for 2 years. All these jobs involved prolonged exposure to extremely loud machinery. David was diagnosed with significant, work-related hearing loss while employed by Rapid Excavation Co. Despite decades of exposure with his previous employers, the last-injurious-exposure rule would typically assign liability for David's hearing loss claim to Rapid Excavation Co., as they were his last employer to expose him to the injurious noise levels that contributed to his cumulative hearing damage.

• Example 3: Repetitive Strain Injury

  Sarah worked as a data entry clerk for "DataFast Services" for 8 years, then for "InfoProcess Solutions" for 6 years, and finally for "QuickType Bureau" for 3 years. All her roles involved intensive, repetitive keyboarding. She developed severe carpal tunnel syndrome in both wrists while working for QuickType Bureau, requiring surgery. Under the last-injurious-exposure rule, QuickType Bureau would generally be responsible for Sarah's workers' compensation claim, as they were the last employer to expose her to the repetitive motions that contributed to the development of her carpal tunnel syndrome, even though her previous employers also contributed to the cumulative strain.