This document establishes the general principle and the technical protocol for the validation of alternative methods in the field of microbiological analysis of food, animal feeding stuff and environmental and veterinary samples (see 5.1.1.2.1) for: — the validation of alternative methods which can be used in particular in the framework of the official control; — the international acceptance of the results obtained by the alternative method. It also establishes the general principles of certification of these alternative methods, based on the validation protocol defined in this document (see 4.2). Where an alternative method is used on a routine basis for internal laboratory use without the requirement to meet (higher) external criteria of quality assurance, a less stringent comparative validation of the alternative method than that set in this standard may be appropriate.