For exposure to toxic substances, when does the 3-year statute of limitations begin?

• A. 3 years from discovery of injury
• B. 3 years from date of injury
• C. 3 years from the later of discovery of injury or the date the injury should have been discovered
• D. 3 years from earlier of discovery of injury, or the date the injury should have been discovered with reasonable diligence

Answer: (D)

For latent injuries from toxic exposure, the statute of limitations uses a discovery-oriented start. You don’t begin counting from the date of exposure; you begin when the injury is discovered, or when it should have been discovered through reasonable diligence, whichever date comes first. The idea is to prevent unfairly cutting off a claim when the injury isn’t apparent yet, but also to avoid indefinite tolling if the injured person could have discovered it earlier with reasonable care.

So the 3-year period runs from the earlier of the date you actually discover the injury or the date the injury should have been discovered with reasonable diligence. For example, if you discover the injury in year two, but with reasonable diligence you should have discovered it by year one, the clock starts at year one and you must sue by year four. If you discover in year three but should have discovered by year four, the clock starts in year three, and you must sue by year six, because you take the earlier date between discovery and should-have-discovered.

This is why that option—calculating from the earlier of discovery or the date the injury should have been discovered with reasonable diligence—best fits how the law handles exposure to toxic substances.