Report on Heat Inactivation of viruses in Antihemophilic Factor Concentrates. by M. M. Mozen et al. States the outcome of a 5 - 6 year research into the heat treatment of plasma and concluded that heating antihemophilic factor concentrates in their lyophilised state at 68 degrees C for 72 hours affects significant viral inactivation. It also stated that the heating process has demonstrated the inactivation of a known quantity of NANB hepatitis.