Latency is defined in the Blakiston's Medical Dictionary, 3rd edition as: the state or quality of being latent. In physiology, the period between the introduction of a stimulus and the response to it, or any stage of an infectious disease in which there are no clinical signs or symptoms of an infection.

Section 35C states that where there is a difference of five years or more between the date of injury (date of exposure) and the INITIAL date on which the injured worker or survivor first became eligible for benefits under MGL c. 152, §§ 31, 34, 34A, or 35, the applicable benefits shall be those in effect on the first date of eligibility for benefits (disability or death).