Pressure Steam steam biological indicator are available for monitoring the efficacy of Steam, H2O2/ Plasma and Ethylene Oxide/ Dry heat sterilization processes. Biological indicators contain bacterial spores on a paper carrier (or tyvek disc for H2O2/plasma) plus a sealed glass ampoule within a vented plastic vial. The glass ampoule contains a proprietary formulation of soybean casein digest culture media with a pH indicator. The pH indicator remains purple when there is no spore growth and yellow when there is spore growth.

This allows quick visual determination of sterilization failures (yellow color).