This part of ISO 16140 describes the protocols for single-laboratory validation of methods for microbiology in the food chain. The protocols in this part of ISO 16140 only validate the method for the laboratory conducting the study. This part of ISO 16140 is applicable to single-laboratory validation of methods used in the analysis (detection or quantification) of microorganisms in ¾ð products intended for human consumption, ¾ð products intended for animal feeding, ¾ð environmental samples in the area of food and feed production, handling, and ¾ð samples from the primary production stage. This part of ISO 16140 is in particular applicable to bacteria and fungi. Some clauses can be applicable to other (micro)organisms or their metabolites, to be determined on a case-by-case-basis. Single-laboratory validation is required if an interlaboratory validation according to ISO 16140-2 is not appropriate, e.g. for in-house methods. Possible applications are: ¾ð validation of new in-house method; ¾ð the first step in the validation process according to ISO 17468[2]; ¾ð extension of the scope of an ISO 16140-2 validated method: e.g. category extension or test portion size; ¾ð modifications of existing methods. Within ISO 17468[2], single-laboratory validation is the first step in the standardization of a method. It can be applied only for methods that are fully specified with regard to all relevant parameters (including tolerances on temperatures and specifications on culture media) and which have already been optimised.