The delay between an exposure or injury-causing event and the first signs of harm.

"Delay" matters because people often assume a claim starts the day a chemical spill, workplace exposure, or contamination happened. That is not always true. A latency period can last days, years, or even decades, especially with toxic exposure, occupational illness, and some cancers. "Exposure" means contact with a harmful substance; it does not guarantee immediate symptoms. "First signs of harm" can mean diagnosable disease, noticeable symptoms, or enough facts that a reasonable person should connect the condition to the exposure.

That distinction affects evidence and deadlines. Bad advice often sounds like this: if you felt fine for years, the old exposure cannot be the cause. That is simply wrong. Many toxic injury claims turn on medical records, work history, testing, and expert proof showing that a long gap between exposure and illness is medically expected, not suspicious. A long latency period can make insurers argue the illness came from something else, so documentation matters.

In South Carolina, the timing issue can be critical because many injury claims are governed by the three-year statute of limitations in S.C. Code Ann. § 15-3-530. For latent injuries, the fight is often over when the harm was discovered, or reasonably should have been discovered, not just when the exposure happened.