Standards of cleanliness in the National Health Service are measured against The National Specifications for Cleanliness in the NHS: A Framework for Setting and Measuring Performance Outcomes, first published in 2001 (a copy of which has already been placed in the Library) and the Patient Environment Action Team (PEAT) annual inspection programme introduced in 2000. This latter programme includes an assessment of ward kitchens. The Healthcare Commission monitors cleanliness by means of its national in-patient surveys and annual health check. It also carries out specialist inspections against the Health Act 2006 code of practice which include an assessment of cleanliness. By all these measures, hospital cleanliness has improved in every year since measurements began in 2000.
No specific assessment has been made of the relative standards of cleanliness as detailed in the question. Production kitchens will be the subject of separate requirements under local environmental provisions.