Abstract
As a policy instrument that is deeply rooted in technology assessment, the precautionary principle examines the effects of a given object on humans and the environment. In practice the principle is rarely used to analyze the effects of our safety measures on the object itself or the way it is produced. Yet it is exactly in the effect on the blood procurement system that blood safety regulations based on the precautionary principle have to be particularly careful, as the vast majority of blood products in the Global North are obtained through donations.