Link to an amendment published at 82 FR 52245, Nov. 13, 2017.

You can find more information concerning the role of MROs in several sections of this part:

§ 40.3 - Definition. §§ 40.47-40.49 - Correction of form and kit errors. § 40.67 - Role in direct observation and other atypical test situations. § 40.83 - Laboratory handling of fatal and correctable flaws. § 40.97 - Laboratory handling of test results and quantitative values. § 40.99 - Authorization of longer laboratory retention of specimens. § 40.101 - Relationship with laboratories; avoidance of conflicts of interest. § 40.105 - Notification of discrepancies in blind specimen results. § 40.171 - Request for test of split specimen. § 40.187 - Action concerning split specimen test results. § 40.193 - Role in “shy bladder” situations. § 40.195 - Role in cancelling tests. §§ 40.199-40.203 - Documenting errors in tests. § 40.327 - Confidentiality and release of information. § 40.347 - Transfer of records. § 40.353 - Relationships with service agents.