OBJECTIVES: Based on the European Standard EN 1040, the validation guidelinesof the German Federal Institute for Drugs and Medical Devices and CPMP guidelines we tested the antimicrobialeffectiveness of a peracetic acid-ethanol sterilization procedure (PES) in allogenic avital bone transplants.STUDY DESIGN: Delipidated human bone spongiosa cubes (15 x 15 x 15 mm) served as tissue. Three envelopedviruses (human immunodeficiency virus type 2, pseudorabies virus, bovine virus diarrhoea virus) and threenon-enveloped viruses (hepatitis A virus, poliovirus, porcine parvovirus) were used. The reduction ofvirus infectivity was measured as TCID50/ml in neutralized supernatants and bone homogenates. Staphylococcusaureus. Enterococcus faecium, Pseudomonas aeruginosa. Bacillus subtilis. Clostridium sporogenes, Mycobacteriumterrae. Candida albicans, Aspergillus niger as well as spores of Bacillus subtilis were tested additionally.PES led to a reduction of virus titres by more than 4 log10. Only HAV showed a reduction below 4 log10(2.87) with residual infectivity. After including a delipidating step for HAV-infected cells, a reductionof over 7 log10 HAV titre was found. For viable bacteria, fungi and spores a titre reduction below thedetection level (5 log10) was achieved after an incubation time of 2 hours. CONCLUSIONS: The peraceticacid-ethanol procedure proved to be a reliable method for the sterilization of human bone transplants(layer thickness < or = 15 mm). However, additional safety measures (anamnestic informations, infectiousserology, HIV-/HBV-/HCV-PCR in case of multiorgan donors) should be taken.