Cross-Contamination: Types and How to Prevent It

Cross-contamination is a leading cause of why food becomes unsafe and causes foodborne illnesses.

As a food handler, it’s your responsibility to prevent cross-contamination so you can keep food safe and prevent people from getting sick.

This article explains how you can keep food safe throughout its flow by preventing cross-contamination.

What is cross-contamination?

Cross-contamination is the transfer of harmful bacteria, viruses, or other biological hazards from one surface or food to another.

It’s commonly confused with cross-contact.

Cross-contact is similar to cross-contamination but occurs with the transfer of a food allergen rather than a pathogen from one surface or food item to another.

There are three ways in which cross-contamination can occur:

• Food-to-food. This type occurs when raw food comes in contact with ready-to-eat (RTE) food.
• Equipment-to-food. This type occurs when you use unclean and unsanitized equipment or other food-contact surfaces like utensils to prepare food.
• People-to-food. This occurs when you don’t wash your hands after they become contaminated and then handle food.

How to prevent cross-contamination

Here is how you can prevent each type of cross-contamination:

Food-to-food

Food-to-food cross-contamination occurs when raw and RTE foods come in contact.

This can happen if you store raw animal foods above RTE foods like salads or sandwiches in the refrigerator.

In this scenario, the juices from the animal foods can drip onto and contaminate the ready-to-eat foods.

Therefore, you should always store ready-to-eat foods on the top shelf.

Food-to-food cross-contamination can also occur if you don’t separate raw and RTE foods during preparation.

Equipment-to-food

Equipment-to-food cross-contamination occurs when you use unclean and unsanitized equipment or other food-contact surfaces.

Chopping chicken on a cutting board and then using the same knife and cutting board to chop a head of lettuce is an example of this type of cross-contamination.

Failing to sanitize a food thermometer between uses is another example of equipment-to-food cross-contamination.

Always wash and sanitize equipment and other food-contact surfaces like counters, utensils, and mixing bowls whenever they become contaminated or after four hours of continuous use.

Use a wiping cloth, a three-compartment sink, and a dishwasher to properly clean and sanitize all equipment.

People-to-food

People-to-food cross-contamination occurs when food handlers contaminate food.

You can contaminate food if you (1):

• have a foodborne illness
• have an uncovered infected wound
• have cold symptoms
• have long nails or wear jewelry
• have contact with an ill person
• don’t wash your hands after they become contaminated
• handle RTE foods with bare hands or contaminated gloves

Practicing good personal hygiene is important but one of the best ways to prevent people-to-food cross-contamination is with proper handwashing.

You must wash your hands anytime they could become contaminated, such as after using the restroom, touching your face or other body parts, handling soiled dishes and utensils, and when changing tasks, such as switching from handling raw foods to working with RTE foods.

The bottom line

Cross-contamination is the transfer of disease-causing organisms known as pathogens from one surface or food to another food.

Cross-contamination can lead to food hazards in three ways — food-to-food, equipment-to-food, and people-to-food.

You can prevent cross-contamination by storing food safely in the refrigerator, washing and sanitizing food-contact surfaces when they become contaminated, practicing good personal hygiene, and washing your hands often.