Minimal or reasonable? Considering the ethical threshold for research risks to nonconsenting bystanders and implications for nonconsenting participants.

When research poses risks to non-participant bystanders, it is not always practicable to obtain their consent. One approach to assessing how much research risk may be imposed on nonconsenting bystanders is to examine analogous circumstances, including risk thresholds deemed acceptable for nonconsenting research participants and for nonconsensual risks imposed outside the research setting. For nonconsenting participants, US research regulations typically limit risks to those deemed to be "minimal." Outside the research context, US tort law tolerates a more flexible "reasonable" risk threshold. This article advances a preliminary case that nonconsenting participants and nonconsenting bystanders exposed to similar research risks may be entitled to the same level of protection, but that risks generated by research may not be special in kind. Thus, limiting research risks to those that are "reasonable," rather than demanding that they be held to the "minimal" standard, may be the best approach for both nonconsenting participants and nonconsenting bystanders. Further work is needed to establish whether the descriptive standards used to support the analogies relied on here are normatively justifiable, as well as the extent to which the minimal risk standard and the reasonable risk standard would lead to meaningfully different outcomes in practice.