Research risks have to meet minimal risk requirements in order for the research to qualify for expedited ethics review, to be exempted from ethics review, or to be granted consent waivers. The definition of “minimal risk” in the Common Rule (45 CFR 46) relies on the risks-of-daily-life and risks-of-routine-tests as comparators against which research activities are assessed to meet minimal risk requirements. While either or both comparators have been adopted by major ethics codes, they have also been criticized. In response (...) to criticisms, elaborations, and alternative comparators have been proposed. In this paper, I approach the search for workable comparators from the point of view that ethical reasoning about minimal risk involves analogical reasoning using comparators. In this regard, I develop two necessary conditions for an adequate minimal risk conception, which I use to assess three comparators. I conclude that the risks-of-routine-tests best fits the analogical reasoning operating in minimal risk assessments. (shrink)