To help you understand your role in keeping food safe, there are four lessons. These lessons teach you the relationship between germs and foodborne illness, critical control points--from purchasing through handling leftovers--when foods may become contaminated, and the importance of handwashing and personal cleanliness. These lessons will help you understand that handwashing is a critical control point for reducing their chance for foodborne illness.
Topics in this lesson include:
- What is foodborne illness?
- Who is at risk?
- How does food become hazardous?
- Why are microorganisms important?
- What is the greatest threat to food safety?
- What conditions encourage bacteria to grow?
- What are the most common foodborne pathogens?
- How can I handle food safely?
- Wash your hands!
Introduction
Many people get sick each year from the food they eat. They may have diarrhea, vomiting, an upset stomach, fever, or cramps. They often think they have the flu, but the real problem is foodborne illness caused by bacteria in the food or viruses transmitted to food eaten a few hours or several days earlier.
Even though we have one of the safest food supplies in the world, there are an estimated two million cases of foodborne illness each year.
Reported cases of foodborne illness
are just the tip of the iceberg
Most foodborne illness can be avoided if food is handled properly. Statistics from the Centers for Disease Control show that the most commonly reported food preparation practice that contributed to foodborne disease was improper holding temperatures, followed by poor personal hygiene, inadequate cooking, contaminated equipment, and food from an unsafe source, as shown on this pie chart (click on the chart for a larger view).
What is foodborne illness?
A foodborne illness is a disease that is transmitted to humans by food. Recent developments in diagnosing and tracking reported illnesses have helped the public become more aware that certain types of illness may be related to the food they ate prior to becoming sick.
The U.S. Public Health Service classifies moist, high-protein, and/or low acid foods as potentially hazardous. High protein foods consist, in whole or in part, of milk or milk products, shell eggs, meats, poultry, fish, shellfish, edible crustacea (shrimp, lobster, crab). Baked or boiled potatoes, tofu and other soy protein foods, plant foods that have been heat-treated, and raw seed sprouts (such as alfalfa or bean sprouts) also pose a hazard. These foods can support rapid growth of infectious or disease-causing microorganisms.
These high-protein foods are classified
as potentially hazardous
Who is at risk?
Infants, young children, pregnant women, the elderly, and people who are chronically ill have a greater risk of developing a foodborne illness because their immune systems may not be able to fight off the bacteria and viruses that cause the illness. Those at greater risk should avoid consuming potentially hazardous foods that are raw or not fully cooked.
 | Infants and children are more vulnerable because their stomachs produce less acid, making it easier for bacteria and viruses to multiply. |
 | Pregnant women are at risk because a fetus does not have a fully developed immune system. |
 | The elderly are more susceptible to foodborne illness because of inadequate nutrition, lack of protein in their diets, or poor blood circulation.
|
 | People who are chronically ill or who take medication that affects their immune system are also at greater risk of becoming sick from a foodborne illness. This could include people with cancer, diabetes, AIDS patients or people who take antibiotics. |
How does food become hazardous?
Food becomes hazardous by contamination. Contamination is the unintended presence of harmful substances or microorganisms in food. Food can become contaminated from
chemical,
physical or
biological sources.
Chemical hazards: Chemical hazards include substances such as cleaning solutions and sanitizers.
Physical hazards: Physical hazards are foreign particles, like glass or metal.
Biological hazards: Biological hazards come mainly from microorganisms including bacteria, viruses and parasites.
What is Cross-contamination?

Keep it straight...
Don't cross-contaminate! Cross-contamination is the transportation of harmful substances to food by:
Hands that touch raw foods, such as chicken, then touch food that will not be cooked, like salad ingredients.
Surfaces, like cutting boards or cleaning cloths, that touch raw foods, are not cleaned and sanitized, then touch ready-to-eat food.
Raw or contaminated foods that touch or drip fluids on cooked or ready-to-eat foods.