ISO 8086|IDF 121:2004 gives general guidelines for inspection and sampling procedures to be used to check the effectiveness of cleaning and disinfection methods used in dairy plants and receiving stations, including milk-collection tankers.

It deals with visual inspection, sampling from plant surfaces (product line, bottle washing equipment, containers, etc.), re-usable product containers, air, sampling of water and aqueous solutions other than those added to the product, and sampling of raw materials and products.

ISO 8086|IDF 121:2004 does not cover equipment normally installed in farms (e.g. milking machinery or refrigerated bulk milk tanks), nor does it deal with the equally important areas of health and hygiene of personnel, factory environment, internal arrangement of the factory, methods of cleaning, packaging materials brought in new from outside (paper, cardboard, plastic, new bottles, etc.), food ingredients and additives, selection of number of units and treatment of the sample in the laboratory.