Experimental work with HIV and HBV has established the stability of these viruses under various conditions. HBV has the potential to remain viable for prolonged periods in dried blood at ambient temperature, but because of the nature of a dried blood residue this is likely to pose a considerably lower risk than fresh, infected blood.
HCV has been found to survive and remain infective for up to 16 hours when dried down in chimpanzee plasma. Although the risk of transmitting infection is therefore reduced as the concentration of infectious virus drops over time, no assumptions about safety should be made when blood-soiled surfaces, equipment and clothing have not been decontaminated. The scale of any blood or body fluid contamination is important when considering how best to clean contaminated materials, and various approaches to cleaning, disinfection and sterilisation are described below.