The invention relates to a chemical indicating composition, an autoclave tape utilizing the chemical indicating composition, and a method of preparing the autoclave tape. The chemical indicating composition of the invention comprises an indicator, an organic silicone modified polymer and a solvent wherein, the indicator comprises a bismuth compound, a sulfur source, and a compound capable of generating alkaline conditions when exposed to steam at a high temperature. The chemical indicating composition can be coated directly onto the non-adhesive surface of the adhesive tape, so as to accomplish the preparation of the autoclave tape in one step.
