Sanitization
Where dishes are to be shared among many, such as in restaurants, sanitization is necessary and desirable in order to prevent spread of microorganisms.
Most institutions have a dish-washing machine which sanitizes dishes by a final rinse in either very hot water or a chemical sanitizing solution such as dilute bleach solution (50-100 parts per million chlorine; about 2ml of 5% bleach per litre of water, approximately one capful bleach per gallon water). Dishes are placed on large trays and fed onto rollers through the machine.
While not environmentally friendly, the use of bleach is critical to sanitation when large groups are involved: it evaporates completely, it is cheap, and it kills most germs. Cabinets, refrigerators, countertops, and anything else touched by people in a large group setting should be periodically wiped or sprayed with a dilute bleach solution after being washed with soapy water and rinsed in clean water.
However, bleach is less effective in the presence of organic debris, so a small amount of food residue can be enough to permit survival of e.g. Salmonella bacteria. Scrubbing followed by soaking in bleach is effective at reducing Salmonella contamination, but even this method doesn't completely eliminate Salmonella bacteria.
In hand-washing, plastic brushes are recommended rather than washclothes or sponges, which can spread microorganisms. Use of soap or sanitizer is mandatory in hand-washing in public food facilities.
Read more about this topic: Dishwashing