14 CFR § 145.206

Each repair station must acknowledge receipt of the part 121 or part 135 operator notification required under §§ 121.1005(e) and 135.505(e) of this chapter prior to performing work for, or on behalf of that certificate holder.

Prior to performing work for or on behalf of a part 121 or part 135 operator, each repair station must notify its employees, contractors, or subcontractors that handle or replace aircraft components or other items regulated by 49 CFR parts 171 through 180 of each certificate holder's operations specifications authorization permitting, or prohibition against, carrying hazardous materials. This notification must be provided subsequent to the notification by the part 121 or part 135 operator of such operations specifications authorization/designation.