The infectious agents causing transmissible spongiform encephalopathies (TSEs), sometimes called prions, are notoriously difficult to completely inactivate or destroy. Here we tested a thermal hydrolysis system which combines saturated steam heating to 180 degrees C (10 bar), with stirring. The 301V-TSE strain, which has been derived by passage of BSE in mice, was used since it is the most thermostable TSE strain tested so far. All detectable TSE infectivity was destroyed, with a clearance factor of greater than 10(5) ID(50). The use of this technology for the decontamination of TSE infected tissue waste and the potential uses of the end-products are discussed. (C) 2009 Elsevier Ltd. All rights reserved.