ZEOSS Ethylene Oxide biological indicators have been developed to control the Ethylene Oxide sterilization process. The biological indicator contains bacterial spores embedded in filter paper in a plastic tube. The specially formulated culture medium is contained in a sealed glass ampoule. When the spores germinate, the liquid color changes in the tube. ZEOSS Ethylene Oxide biological indicators give results in 48 hours at 37±2 °C.