Self-adhesive, nontoxic, chemical process indicators change from yellow to blue when exposed to 3–6mg/L vapor hydrogen peroxide in a complete STERRAD® 100 or 100 S Sterilization System cycle.

When the label is exposed, the imprint reads “BLUE IS H2O2 EXPOSED.” Indicators are stable for at least 18 months from date of manufacture when they are stored at room temperature.