Children's Risk Level. CRL 1 (45 CFR 46.404)—Research not involving greater than minimal risk. CRL 2 (45 CFR 46.405)—Research involving greater than minimal risk but of possible direct benefit to the child, in which the risk is at least as favorable to the subject as that presented by available alternative approaches. CRL 3 (45 CFR 46.406)—Research involving greater than minimal risk and no prospect of direct benefit to the individual child, but likely to yield generalizable knowledge about the disorder or condition, in which the risk is minor relative to the potential improvement in knowledge to be applied to general understanding. CRL 4 (45 CFR 46.407)—Research not meeting the specifications above, but which presents an opportunity to understand, prevent or alleviate a serious problem affecting the health and welfare of children. For further information, see the form for Special Population Review – Children/Minors in Section 10, "Forms," of the UAB IRB Guidebook.