21 C.F.R. § 117.160
(b) The validation of the preventive controls:
(1) Must be performed (or overseen) by a preventive controls qualified individual:
(i)
(B) When necessary to demonstrate the control measures can be implemented as designed:
(1) Within 90 calendar days after production of the applicable food first begins; or
(2) Within a reasonable timeframe, provided that the preventive controls qualified individual prepares (or oversees the preparation of) a written justification for a timeframe that exceeds 90 calendar days after production of the applicable food first begins;
(c) You do not need to validate: