Sterility assurance level (SAL)

A device labeled sterile is typically expected to meet a SAL of 10^-6, a one in a million chance of a surviving microorganism. The SAL claimed has to be supported by the sterilization validation.

The probability of a single viable microorganism occurring on an item after sterilization.

FDA guidance: Deciding When to Submit a 510(k) for a Change to an Existing Device (October 2017), Appendix C, Significant Terminology