The length of time after which no causal relationship can reasonably be established. This length of time is the period from the last exposure to the point of time at which an exposed person has demonstrated the initial signs or symptoms.
Source:
PAC, 2001, 73, 993. 'Risk assessment for occupational exposure to chemicals. A review of current methodology (IUPAC Technical Report)' on page 1023 (https://doi.org/10.1351/pac200173060993)