Overkill cycle

A sterilisation cycle designed to deliver at least a 12-log reduction of a highly resistant biological indicator, such as Geobacillus stearothermophilus spores, regardless of the actual bioburden. Because real bioburden is usually much lower and less resistant, an overkill cycle gives very high sterility assurance. It is used for heat-stable items like equipment parts, glassware, garments and culture media. Heat-sensitive products use a bioburden-based approach instead.