How to Prevent the Physical and Biological Contamination of Food

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How to avoid the physical and biological contamination of food.

Food contamination is dangerous and potentially deadly; however there are simple measures that can be taken in every kitchen to minimize the risk of food contamination.

Physical contamination of food occurs when a foreign object mixes with food and becomes either danger for or a nuisance to the consumer. Foreign objects can include bones or hair or jewelry or any number of objects that mixes with the food during the food preparation, creation or delivery. Physical contamination can occur when food is not properly stored.

Biological contamination of food occurs when microorganisms, such as bacteria, viruses, fungi and parasites, enter food from a variety of sources including poor hygiene, refuse and pests. Biological contamination is the most common type of contamination and can have dire consequences.


After food is purchased, take it immediately home and store it in the proper containers and at the proper temperature. Never store food in metallic containers and never put meat or other articles that drip on the top shelf of the refrigerator. All foods that require refrigeration must be stored below 40 degrees Fahrenheit.

Refrigerators should have open shelves and must never be overloaded. Overloaded shelves do not allow for cold air to circulate and raise the temperature of the refrigerator as well as the food inside.

Refrigerators must be cleaned and sanitized regularly to prevent the accumulation of physical contaminants. Foods should be covered to prevent cross-contamination and absorption of other food orders. Never just cover an open can and put it in the refrigerator. Again, food must be stored in plastic.

Preparation and Put Away

Most food is contaminated during the preparation process. Make sure all surfaces are clean and sanitized and make sure that hands are properly washed, with warm soap and water, before handling any food.

Never leave food out for more than two hours as microorganism can multiply rapidly as food warms and/or cools. Immediately prepare food after you remove it from the refrigerator.

After food is consumed, put it away immediately. Package leftovers in plastic covered containers or labeled plastic bags and immediately place in the refrigerator or freezer. Always label leftovers with the name of what you are storing and the date you are storing it so that you will know exactly what it is and when you should use it by. Become familiar with food storage limits and toss any food that has exceeded those limits.

Cleaning and Sanitizing

Hot soapy water is perfect for cleaning. Wash surfaces with clean, hot, soapy water to remove particles of food and wash as many microorganisms as possible from all surfaces. Rinse with clean, clear, hot water. The rinse step is to further remove microorganisms and does not interfere with the effectiveness of sanitizer.

Use an approved sanitizing agent such as bleach. If bleach is being used as the sanitizer, the solution should be about 70 degrees F. Temperatures higher cause the chlorine in the bleach to turn into gas. This sanitizing step will reduce the number of microorganisms and bacteria on surfaces.

More Tips to Staying Food Safe

It is not easy today with all of the food recalls. Currently there is a recall on Romaine lettuce. One way to stay safe is to always keep up with the recalls and food warnings. You can keep up to date at the FDA food recall website.

Another tip is to always clean the cutting board. Whether it is vegetables, fruits or meat, always clean the cutting board before you change foods. For example, if you are preparing chicken and then cutting vegetables, always clean the cutting board before you start preparing another type of food.

Wash every utensil. If you use a knife to cut the chicken or meat, wash that knife thoroughly before you use that knife to cut veggies or fruits.


Elizabeth Chapin-Pinotti
Posted on May 7, 2010
Posted on May 7, 2010
Posted on May 7, 2010