With Ireland's blood supply compromised in the 1980s, the impact upon its haemophiliac community was unprecedented. Thus far, academic attention has focused on apportioning blame and identifying administrative failure: what the government knew about Human Immunodeficiency Virus (HIV), Acquired Immune Deficiency Syndrome (AIDS) and Hepatitis C; and when the blood supply was compromised. Our task is to explain why the crisis emerged. We maintain it was not an issue of risk management, but risk assessment. Prior to the 1970s, decisions about risk were refracted through government channels (ministers, civil servants and medico-scientific experts, i.e. the realm of the political/legal). By the 1980s, risk assessment/management were separated and Government was predisposed to accept market decisions (the realm of the economic/legal). Here intervention is recognised as legitimate only if a risk is established and, even then, it must be proportionate. A balance must be struck between competing objectives: safety, innovation, cost, competitiveness and free trade. Crucially, this reform precluded a precautionary approach.