What Causes Cross-Contamination?
There are three main classifications of cross-contamination. The causes vary based on these classifications.
Naturally, all foods contain microorganisms, which must be killed to prevent causing foodborne diseases. However, these microorganisms can be transferred from one food item to another before processing. Here are a few instances when food-to-food contamination occurs:
- Adding poorly washed lettuce or other vegetables to a salad full of ingredients.
- Putting processed and raw foods near each other.
- Storing food for too long (molds can thrive even in low temperatures).
Poor sanitization is the main culprit here. Yes, utensils and other food equipment can be contaminated no matter how properly you store them. Equipment-to-food contamination may occur when:
- Using a knife or cutting board for high-risk foods such as raw meat and then using the same equipment to cut fresh produce.
- Storing food items in poorly maintained storage units (improper cleaning can be a recipe for pest infestation).
- Placing food on dirty or unsanitized surfaces.
Pathogens such as Staphylococcus aureus naturally live on humans; hence, they can easily be transferred to anything you touch. Specifically, people-to-food contamination can occur in these instances:
- Improper handwashing after going to the toilet.
- Attending to food when sick (you could transfer your virus or bacteria through coughing, etc.).