In catering, cleaning is defined as the systematic removal of dirt, grease, grime and food particles. Cleaning is the first stage in a food safety regime. Cleaning can also occur in rooms, corridors, etc. Here it is the removal of dirt, dust accumulations and grease. In order to remove grease, in either kitchens or corridors, a chemical must be employed to bring the grease, grime and dirt into solution form. When in solution form it must be held together and subsequently flushed or washed away. The chemical used for cleaning is a detergent. This is the first process in any food safety operation to remove pathogens as well as the dirt build up. If a detergent is polarised it also kills pathogens. The detergent label will state cationic or anionic if it is polarised. The "charged" detergent will rupture the pathogens' membrane and cause it to lyse or die. In many circumstances this will be sufficient to control pathogens in a kitchen and ensure food safety.
Although some detergents will kill pathogens, all disinfectants, by their very definition, will kill all pathogens. Disinfectants include chlorine based products such as bleach, quaternary ammonium compounds, alcohols, biguanides, amphoterics and iodophors. By and far the best and most cost effective method of disinfection is hot water, above 82 degrees Celsius. Hot water does not taint, it is environmentally friendly and does not give pathogens a chance to develop immunity to it, as do the other chemicals.
As with hand washing, we should be using only detergents to remove the bacteria, not disinfectants, unless its hot water, as the bacteria will eventually mutate, as per Darwin's theory, to survival of the fittest. Many television adverts will stipulate that "X Brand" bleach will kill 99% of all germs. What happens to the 1%? They survive, because of mutation, and proliferate. That 1% may be the next 99%, how do we kill them?
A sanitiser is a chemical that removes dirt, grease and grime and kills bacteria. In other words it is a combined detergent and disinfectant. This is a chemical that is used quite extensively in catering establishments such as fast food outlets.
Sterilisation is the destruction of all bacteria and their spores. Disinfection does not kill spores. The only way to achieve sterilisation is by heating to 121 degrees Celsius. This temperature is used in autoclaves and in the canning industry, where it is termed commercial sterilisation or the "Botulinum Cook" (So named because of the destruction of C botulinum spores in canned food).
Food safety, then, begins with a strict cleaning regime, which may or may not include disinfection, depending on the detergent.