Much of the liability discourse takes into account the perceptions and roles of other stakeholders, both inside and outside the blood supply system. The third discourse -risk as precaution -does that too but also seems to treat problems on a case-by-case basis as uncertainty cannot be fully removed or explained. It is a view of risk often held and articulated by system administrators. A precautionary approach has been based on a changed perspective toward patients and institutional/ professional partners. And precaution -taking care -is necessary as interests and ways to achieve them may be dissimilar. The blood supplier sees precaution as necessary because of these dissimilarities.