There are three major hazards that may be introduced into the food supply any time during harvesting, processing, transporting, preparing, storing and serving food. These hazards may be microbiological, chemical or physical.

Microbiological Hazards

Microbiological hazard occurs when food becomes contaminated by microorganisms found in the air, food, water, soil, animals and the human body. Many microorganisms are helpful and necessary for life itself. However, given the right conditions, some microorganisms may cause a foodborne illness. Microorganisms commonly associated with foodborne illnesses include bacteria, viruses and parasites.

Chemical Hazards

Chemical hazards can occur at any point during harvesting, storage, preparation and service. When toxic chemicals used for pest control or for cleaning and sanitizing food contact surfaces and food preparation equipment come into contact with food, the food may be contaminated by those chemicals.

Toxic metals such as copper, brass, cadmium, lead and zinc can be a source of chemical contamination. Zinc, used in galvanized containers (garbage cans) and in gray enamelware containers which may be plated with anatomy or cadmium, can make acidic foods such as orange juice or tomato sauce and pickles poisonous. Pottery dishes with lead glazes should not be used to prepare or serve food.

Intentionally added chemicals help to maintain a food’s freshness or to enhance flavors in foods. Check the food ingredient label for more information about the additives. Excessive use of some additives has been linked (see Fact Sheets on Food Allergies and Food Additives) to cases of lethal allergic reactions
particularly among sensitive individuals, in particular, asthmatics.

Foodservice establishments are prohibited by law from using sulfites to maintain product freshness. However, they are still approved for use in some food processing operations, for example, processing shrimp and manufacturing wine. If they are used, the product must be clearly labeled.

Physical Hazards

Physical hazards usually result from accidental contamination and /or poor food handling practices. Examples include, slivers of glass, human hair, nails, false nails, nail polish, pieces of jewelry, metal fragments from worn or chipped utensils and containers, dirt, stones, frilled toothpicks.

Pesticides may leave residues on fruits and vegetables. In general, these residues can be removed by scrubbing the surface and washing with water.

Food irradiation is classified as a food additive and is regulated by the Food and Drug Administration (FDA). Irradiation is a process which destroys pathogenic and spoilage microorganisms without compromising safety, nutrition or quality and significantly lengthens storage life. In general, spices are irradiated as a means of controlling bacterial growth and mold. According to Dr. Donald Thayer of the USDA Agricultural Research Service, irradiation looks promising as a treatment for controlling cylospora in fresh produce like raspberries . Contact your local Cooperative Extension office for the latest information on irradiation.

 
Revised 6/00
University of Rhode Island
Cooperative Extension Food Safety Education