ISO 4831:1991

This second edition cancels and replaces the first edition (ISO 4831:1978). It is intended to provide general guidance for the examination of products not dealt with by existing International Standards. These guidelines may not be appropriate for some products in every detail, and for some other products it may be necessary to use different methods. The technique described here is less precise than that described in ISO 4832. Gives references, and the definition of the term coliforms. Specifies principle, culture media and dilution fluid, apparatus and glassware, sampling, preparation of the test sample, procedure, expression of results and test report.