Disinfection, other than by heat, is ineffective unless all surfaces have previously been thoroughly cleaned to remove interfering materials. Cleaning is therefore extremely important as part of a two-stage cleaning and disinfection (sanitation) programme. The author describes the principles of sanitation, the chemicals and equipment involved, and the programme of events to be followed. For food products of 'low risk' (in terms of stable shelf life and safety), traditional sanitation programmes are adequate and in some cases disinfection may not be required. However, disinfection is essential for 'high-risk' food products, but this cannot be effectively undertaken without due consideration of hygienic design and possible cross-contamination. To ensure continued satisfactory performance of a sanitation programme, routine assessments should be undertaken.