3.1 How Food Handlers Can Contaminate Food

Food handlers are the first line of defense in food safety—but they can also be the primary source of contamination. Studies show that poor personal hygiene and improper food handling practices account for a significant percentage of foodborne illness outbreaks.

The good news? Contamination from food handlers is almost entirely preventable through proper training, monitoring, and enforcement of personal hygiene policies.

Routes of Contamination

Food handlers can contaminate food through several pathways:

1. Hands - The #1 Contamination Vehicle

Your hands are covered with microorganisms—both beneficial and harmful. A single gram of feces (about the size of a grain of rice) can contain:

• 1 billion bacteria
• 10 million viruses
• 1,000 parasite cysts

When food handlers touch their face, hair, or other body parts, these pathogens transfer to their hands. Without proper handwashing, those pathogens transfer directly to food, utensils, and equipment.

Common hand-related contamination scenarios:

• Using the restroom and not washing hands properly
• Touching your face, hair, or nose
• Handling raw meat, then touching ready-to-eat food
• Touching dirty surfaces (trash cans, cleaning cloths, money)
• Scratching a wound or touching a bandage

2. Clothing and Aprons

Dirty work clothes harbor pathogens from food spills, splash, and contact with contaminated surfaces.

Contamination risks:

• Aprons used for raw food preparation, then worn while handling ready-to-eat foods
• Wiping hands on aprons instead of washing them
• Storing dirty aprons near clean uniforms
• Wearing the same apron multiple days without laundering

Best practice: Change aprons when switching between raw and ready-to-eat food tasks. Store dirty aprons separately from clean ones.

3. Hair and Facial Hair

A single human head has 80,000-120,000 hair follicles, and we naturally shed 50-100 hairs per day. Hair can carry Staphylococcus aureus bacteria, which causes staph food poisoning.

The risks:

• Hair falling directly into food
• Touching hair, then touching food without handwashing
• Not restraining beards or mustaches near food

Food Code requirement: Food handlers must wear effective hair restraints (hats, hairnets, beard nets) when working with exposed food.

4. Saliva and Respiratory Secretions

Every cough or sneeze releases thousands of droplets containing bacteria and viruses into the air. These droplets can travel 6 feet or more and contaminate food, surfaces, and equipment.

Contamination pathways:

• Coughing or sneezing near food
• Not covering mouth properly when coughing
• Touching mouth or nose, then handling food
• Tasting food with fingers or utensils that return to food

Bare-Hand Contact with Ready-to-Eat Foods

One of the most tested topics on the ServSafe exam is the prohibition of bare-hand contact with ready-to-eat (RTE) foods.

What Are Ready-to-Eat (RTE) Foods?

Ready-to-eat foods are foods that will be served without additional cooking or washing to remove microorganisms. These foods are particularly vulnerable to contamination because there's no "kill step" before they reach the customer.

Examples of RTE foods:

• Salads (tossed salads, potato salad, coleslaw)
• Sandwiches and deli meats
• Fresh fruits and vegetables for immediate service
• Bread and baked goods
• Cheese and cold cuts
• Sushi and raw seafood
• Ice for beverages
• Garnishes (lemon wedges, parsley)

The Rule: No Bare-Hand Contact

FDA Food Code requirement: Food handlers may NOT touch ready-to-eat foods with bare hands. Instead, they must use:

For the Exam: Memorize this rule. Many questions test scenarios where food handlers touch RTE foods. The answer is almost always that bare-hand contact is prohibited.

Exception: High-Temperature Cooking

Bare-hand contact is acceptable if the food will be cooked to at least 145°F or higher immediately after handling. This "kill step" destroys pathogens.

Examples where bare-hand contact is OK:

• Forming raw hamburger patties (cooked to 155°F)
• Breading raw chicken (cooked to 165°F)
• Preparing pizza dough that will be baked
• Shaping raw meatballs for cooking

Not OK:

• Shaping ready-to-eat sushi rice
• Assembling cold sandwiches
• Tossing salad ingredients

Behaviors That Cause Contamination

Certain behaviors make contamination almost inevitable:

Contamination Through Bodily Fluids

Food handlers can contaminate food through:

Infected wounds or boils:

• Open cuts, burns, and sores shed Staphylococcus aureus
• Must be covered with waterproof bandage AND single-use glove or finger cot

Sweat:

• Can drip into food and carry bacteria
• Work in well-ventilated areas; wipe sweat with clean towel (then wash hands)

Vomit and feces:

• Even microscopic amounts cause illness (Norovirus, Hepatitis A)
• Ill employees must be excluded or restricted (covered in Section 3.3)

For the Exam: Know that ANY open wound must be covered with a waterproof bandage AND a glove or finger cot. The bandage alone is not enough.