Cross-contamination occurs when a food product receives harmful
microorganisms from contact with other food items, personnel, utensils, equipment, and
surfaces. Cross-contamination is not specifically related to temperature but to all
phases of food handling, including storage and personnel control. It will be discussed
here since it frequently occurs during food preparation and intensifies the problems
caused by inadequate temperature control. For example, chicken could be
contaminated if it is mixed with other contaminated foods; if it is cut by a knife used on
another contaminated chicken; or if touched by the contaminated hands of a food
service employee or by contaminated surfaces. During an inspection, check that the
food service employees are taking steps to minimize cross-contamination. These steps
include cleaning and sanitizing equipment, utensils, and surfaces after use; requiring
employees to wash their hands after handling raw foods; covering foods; and not using
the same utensils and equipment for raw and cooked foods.
a. Failure to maintain safe temperatures during food handling is the leading
cause of foodborne disease.
b. Failure to maintain adequate temperature also causes significant waste due
c. Safe temperatures mean 45 F or below and 140 F or above. The
temperature range between 45 F and 140 F is called the temperature danger zone.
d. Three hours is the maximum time that a potentially hazardous food can be in
the danger zone without becoming dangerously contaminated. A food does not have to
be in the danger zone for 3 consecutive hours for contamination to occur. Each
separate period of time that exposes the food to danger zone temperatures counts
toward the 3 hours.
e. There are certain basic facts about food cooling that form the basis of food
cooling techniques. These are:
(1) Solid foods cool more slowly than liquids.
(2) Foods with a high fat or starch content cool slowly.
(3) Foods with a small surface area cool more slowly than foods with a large
(4) Large, deep portions of food cool more slowly than small, shallow