The latest in the series of standards for method validation has just been published.

Testing for microorganisms in food is an essential step in the food safety process to determine there are no organisms or pathogens present that are likely to cause harm.

But methods abound, validating and verifying that a method is robust enough to meet strict food safety regulations and keep consumers safe is equally important.

ISO has a series of standards developed by international experts to do just that, the latest of which has just been published.

ISO 16140-3, Microbiology of the food chain – Method validation – Part 3: Protocol for the verification of reference methods and validated alternative methods in a single laboratory, provides the procedures and acceptance criteria for implementing test methods in a laboratory. It is designed to help food and feed testing laboratories, test kit manufacturers, competent authorities, and food and feed business operators to implement microbiological methods in their laboratories.

ISO 16140-3 includes two phases, the implementation verification study and the (food) item verification study, with separate protocols for the verification of qualitative and quantitative microbiological methods, and confirmation and typing methods. It also provides an informative protocol for the verification of reference methods not yet fully validated.

The standard joins other parts in the ISO 16140 series, which provide protocols for the validation of new and alternative methods. This new standard specifically focuses on the procedure for laboratories to follow, allowing them to verify their use of validated methods.

Other parts in the series are:

• ISO 16140-1, Microbiology of the food chain – Method validation – Part 1: Vocabulary


• ISO 16140-2, Microbiology of the food chain – Method validation – Part 2: Protocol for the validation of alternative (proprietary) methods against a reference method


• ISO 16140-4, Microbiology of the food chain – Method validation – Part 4: Protocol for method validation in a single laboratory


• ISO 16140-5, Microbiology of the food chain – Method validation – Part 5: Protocol for factorial interlaboratory validation for non-proprietary methods


• ISO 16140-6, Microbiology of the food chain – Method validation – Part 6: Protocol for the validation of alternative (proprietary) methods for microbiological confirmation and typing procedures

The ISO 16140 series of standards was developed by ISO technical committee ISO/TC 34, Food products, subcommittee SC 9, Microbiology, whose secretariat is held by AFNOR, ISO’s member for France. It can be purchased from your national ISO member or the ISO Store.