Re: EO Indicators on Pouch and/or Carton
The relevant statement regarding chemical indicators within ANSI.AAMI/ISO 11135-1:2007 is Section 8.8, second sentence.
EO sterilization per that standard of course is never performed on a verified-by-indicator basis. It always is performed in a validated-consistent manner to a process specification that is established by standardized means. Thus no indicators are used to verify sterilization of production loads because all of the work to establish the standardized cycle parameters to consistently achieve a 10-to-the-minus-sixth reduction under worst case conditions has already been done during process validation.
The indicators that are used during establishment of the validity of the sterilization process, i.e. biological indicators, are required in Section 8.6 to be placed "within the product at location(s) where sterilizing conditions are most difficult to achieve or be placed within a PCD", and the PCD at its specified location must be separately validated to be more difficult to sterilize than the most-difficult-to-sterilize part of the product. Thus putting such an indicator on the outside of a pouch, or anywhere else on the outside of packaging, probably would be unacceptable because it would not be the most-difficult-to-sterilize part of the product.
But, any indicator can be used for anything else, including providing evidence to customers that the claimed exposure to EO actually occurred, as long as that indicator isn't the basis for a product-is-sterile claim.