This document specifies the enumeration of Clostridium (C.) perfringens by colony-count technique. This part of ISO 15213 is applicable to: - products intended for human consumption; - products intended for animal feeding; - environmental samples in the area of food and feed production, handling, and; - samples from the primary production stage. This technique is intended to be used when the number of colonies sought is expected to be more than 10 per ml or per g of the test sample.