The use of validated methods is an important requirement for obtaining reliable results with a specific method. It also facilitates the comparability of results obtained with the same method in different laboratories. Validation procedures covered by ISO 16140 involve various aspects of validation, such as validation of alternative (proprietary) methods, single laboratory validation, validation of (alternative) methods using a limited number of laboratories, and verification of methods (demonstration of a laboratory to correctly apply a validated method). In addition, there is a close link to ISO 17468 describing the procedure for the validation of the standard methods themselves. This Part 1 of ISO 16140 defines general terms and definitions relating to method validation of microbiology in the food chain. This part of ISO 16140 is applicable to the validation of methods for the analysis (detection or quantification) of microorganisms in: - 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 document has been prepared by Technical Committee ISO/TC 34 "Food products", Subcommittee SC 9 "Microbiology" in collaboration with Technical Committee CEN/TC 275 "Food analysis - Horizontal methods", Working Group 6 "Microbiology of the food chain" the secretariat of which is held by AFNOR (France). Regarding the German collaboration Working Committee NA 057-01-12 AA "Validierung mikrobiologischer Verfahren" ("Validation of microbiological methods") at DIN Standards Committee Food and Agricultural Products (NAL) is responsible.