14 CFR §120.123

1. (a)Except for those testing processes applicable to persons testing pursuant to § 120.1(d), no part of the testing process (including specimen collection, laboratory processing, and MRO actions) shall be conducted outside the territory of the United States.
   1. (1)Except for those persons testing pursuant to § 120.1(d), each employee who is assigned to perform safety-sensitive functions solely outside the territory of the United States shall be removed from the random testing pool upon the inception of such assignment.
   2. (2)Each covered employee who is removed from the random testing pool under this section shall be returned to the random testing pool when the employee resumes the performance of safety-sensitive functions wholly or partially within the territory of the United States.
2. (b)Except for those persons testing pursuant to § 120.1(d), the provisions of this subpart shall not apply to any individual who performs a function listed in § 120.105 by contract for an employer outside the territory of the United States.