A hydrogen peroxide vapor biological indicator and growth medium for testing, validation,and routine monitoring of applications with VHP Biodecontamination Units using patented STERIS VHP process technology. Spordex VH2O2 Biological Indicators contain a known population of Geobacillus stearothermophilus spores. During a typical biodecontamination cycle, the biological indicator is inactivated with hydrogen peroxide vapor. Inactivation is verified using biological indicator media.