The main sources of potential harmful microorganisms in the home are contaminated food (foodborne),
contaminated water (waterborne), infected persons, air, insects or pets. Under favourable circumstances
(temperature, pH, relative humidity), pathogenic microorganisms are able to survive and/or replicate in
large scale. In domestic kitchens, foodborne infection can result from incorrect storage of foods,
particularly with respect to temperature, contamination of raw or cooked foods before consumption, by
contact with other foods or utensils carrying pathogens, and inadequate or poorly controlled cooking
which may allow persistence of pathogens in foods. This transfer of microorganisms from people,
objects or contaminated food to another food or material is known as cross-contamination. People can be
a source of cross-contamination to foods when, for example, handle foods, touch raw meats and prepare
other foods without properly washing hands between tasks. Contamination can also be passed from
kitchen utensils or equipment when contacting food. This happens when utensils or equipment are not
efficiently cleaned and sanitized between each use. Contamination from food to food occurs mainly
when raw foods come into contact with cooked or prepared foods. Safe working practices will reduce or
even avoid this process.