This Standard sets out a method for estimating the number of colony-forming units (CFUs) in suitable liquids using a membrane filtration technique.

The method is applicable only to liquids that can be efficiently filtered without causing a build-up on the filter.

NOTE: The membrane filtration method is most suitable when the microorganisms are in low concentration, e.g. in rinse waters collected from cleaned and sanitized pipelines or tanks. The method is suitable for microbiological assessment of water supplies to processing plants.