21 C.F.R. § 50.52
Any clinical investigation within the scope described in §§ 50.1 and 56.101 of this chapter in which more than minimal risk to children is presented by an intervention or procedure that holds out the prospect of direct benefit for the individual subject, or by a monitoring procedure that is likely to contribute to the subject's well-being, may involve children as subjects only if the IRB finds that:
[66 FR 20598, Apr. 24, 2001, as amended at 78 FR 12951, Feb. 26, 2013]