Food Poisoning: How Does Food Become Contaminated?

Most people are familiar with the symptoms of food poisoning, such as nausea and diarrhea, but how does food become contaminated in the first place? It depends. Microbes, more commonly known as just germs, can infect food on the farm, in the kitchen, or anywhere in between if adequate safety precautions aren’t observed. See FindLaw's Dangerous Foods section for related articles and resources.

The following sources of food poisoning illustrate the different ways food can become contaminated:

Animals

Many germs that cause illness in humans live in the intestines of healthy animals raised for food, including E. coli or its longer scientific name - Escherichia coli. They typically remain in the discarded portions and thus never make it to the dinner plate. However, meat and poultry can become contaminated during slaughter if it comes into contact with just small amounts of the animal's intestinal contents.

Additionally, fresh fruits and vegetables, even those labeled "organic," can be contaminated if washed or irrigated with water contaminated by animal manure or human sewage. All fresh produce should be washed prior to eating.

Food Handling

Food can be contaminated by farm workers, cooks, waiters, and others who handle it. This is often the result of people touching food after failing to wash their hands when using the bathroom, particularly shigella (a foodborne bacteria that causes diarrhea, fever, and stomach cramps) and norovirus (often called "stomach flu" which also causes nausea, vomiting, stomach cramps, fever, and fatigue). Cross-contamination with other raw food products can also spread germs that cause illness.

Food Preparation

In the kitchen, germs can be transferred from one food to another by using the same knife, cutting board, or other utensil without washing it properly in between. Fully cooked foods can become re-contaminated if they touch other raw foods that contain certain germs.

Food Storage

Many bacterial microbes need to multiply to larger numbers in food in order to cause disease. Under warm and moist conditions, for instance, slightly contaminated food left out overnight can become highly infectious as the germs multiply. Prompt refrigeration or freezing typically prevents this growth. High salt, sugar, or acid levels also inhibit bacteria growth.

Heating Food

Germs and other things that cause foodborne illness usually can be killed when heated. Heating food to an internal temperature above 160 degrees Fahrenheit or 78 degrees Celsius, even for a few seconds, is enough to kill most bacteria, viruses, or parasites. Toxins produced by bacteria vary in their sensitivity to heat. For instance, the toxin that causes botulism is inactivated by boiling, whereas the staphylococcal toxin isn’t. Botulism is a potentially fatal form of food poisoning that usually causes illness within 18-36 hours of exposure. Staphylococcal usually causes no illness in healthy people.

Additional Resources

For more information on food poisoning and food safety, see the resources listed in this FindLaw article.

Get a Free Food Poisoning Claim Review 

If you eat contaminated food at a restaurant and get sick as a result, you need medical help and then legal help. Talk to an experienced personal injury attorney in your area who will review your case for free and can help you decide what to do next.

Next Steps

Contact a qualified product liability attorney to make sure your rights are protected.

Help Me Find a Do-It-Yourself Solution