- STEAMPlus is an immediate readout integrator for use in gravity, prevacuum and flash cycles. This product is tested to ST-60 and ISO 11140-1:2005 performance claims of Class 5 integrating integrators. Four inch strip has distinct pass/fail criteria and allows for easy removal from packs. The STEAMPlus is FDA cleared as, equivalent in performance to a biological indicator, and offers the highest level of sterility assurance from a chemical indicator. The STEAMPlus does not replace the routine use of a biological indicator.