Reducing the exposure to allogenic blood products has important clinical, ethical and cost implications. Serious hazards of transfusion (SHOT) continue to be reported (Figure 1), of which the most important are incompatible reactions due to human error and acute transfusion reactions, followed by transfusion-related graft-versus-host reaction and acute lung injuries. The National Blood Service (NBS) for England and North Wales issues about 2.9 million units of blood annually of which 50% are used perioperatively. The theoretical potential for blood transmission of new variant Creutzfeldt-Jacob disease (nvCJD) has recently placed new demands on the NBS: • in 1998 the NBS introduced leucodepletion of all donor blood • plasma for children born after 1996 is imported • the donor pool may be reduced by 10-50% when the nvCJD blood screening test is introduced, further jeopardizing the national blood supply • the total costs are over £150,000,000.