Key Takeaways

  • 48 million Americans get foodborne illness annually (CDC)
  • FAT TOM: Food, Acidity, Temperature, Time, Oxygen, Moisture
  • Biological hazards (bacteria/viruses) cause most foodborne illness
  • High-risk groups: elderly, children under 5, pregnant women, immunocompromised
  • Three types of contamination: biological, chemical, physical
Last updated: January 2026

7.1 Understanding Foodborne Illness

Foodborne illness (food poisoning) is caused by eating food contaminated with harmful microorganisms or their toxins.

Foodborne Illness Statistics

According to the CDC:

  • 48 million Americans get sick from foodborne illness each year
  • 128,000 are hospitalized
  • 3,000 die

Types of Contaminants

1. Biological Hazards (most common):

  • Bacteria
  • Viruses
  • Parasites
  • Fungi (molds, yeasts)

2. Chemical Hazards:

  • Cleaning chemicals
  • Pesticides
  • Toxic metals (lead, copper)
  • Food additives

3. Physical Hazards:

  • Glass fragments
  • Metal shavings
  • Jewelry
  • Stones, pits
  • Bones
  • Hair

Conditions Bacteria Need to Grow: FAT TOM

Bacteria need six conditions to grow, remembered by the acronym FAT TOM:

LetterFactorIdeal Conditions
FFoodHigh protein, high carbohydrate
AAcidity (pH)Neutral: pH 4.6-7.5
TTemperatureDanger zone: 41°F-135°F
TTime4+ hours in danger zone
OOxygenVaries by bacteria type
MMoistureWater activity above 0.85

High-Risk Populations

Some people are more vulnerable to severe foodborne illness:

  1. Elderly (65+) - Weakened immune systems
  2. Young children (under 5) - Immune systems still developing
  3. Pregnant women - Immune changes during pregnancy
  4. Immunocompromised - HIV/AIDS, cancer, diabetes, organ transplant patients

For the Exam: Remember FAT TOM and the four high-risk populations. These are frequently tested topics.

Annual Foodborne Illness in the US (CDC Data)
Test Your Knowledge

What does FAT TOM stand for?

A
B
C
D
Test Your Knowledge

Which group is NOT considered a high-risk population for foodborne illness?

A
B
C
D
Test Your Knowledge

Which type of contamination is the most common cause of foodborne illness?

A
B
C
D