Monitoring for conditions sufficient for steam sterilization is generally carried out by placing an appropriate sterilization indicator along with the product and/or article to be sterilized within a sterilization chamber. A variety of sterilization indicators, including chemical and biological indicators, are known and used for this purpose. Chemical indicators offer an advantage in that they can be read immediately at the end of a sterilization process. For example, internal chemical indicators are placed within an instrument tray prior to steam exposure. These indicators are read in the operating room upon opening the steam-exposed tray, prior to instrument removal. Process indicators such as labels and autoclave tapes have been used to indicate that a wrapped instrument tray or other wrapped article or articles have been exposed to steam.