Which of the following could be responsible for allergenic cross-contact?

The answer is that not cleaning a work surface thoroughly before preparing an allergen-free meal could lead to allergenic cross-contact. This situation arises because surfaces that have previously come into contact with allergenic foods may still contain residues of those allergens. If a work surface is not properly cleaned, microscopic traces of allergens can remain, which can then transfer to allergen-free foods, posing a serious risk to individuals with food allergies.

In situations involving food allergies, even the smallest amount of an allergen can trigger an adverse reaction in sensitive individuals. Therefore, thorough cleaning of food preparation areas is crucial to ensure safety and prevent cross-contact.

The other options involve practices that promote food safety but do not directly contribute to allergenic cross-contact. For instance, cleansing a spill immediately helps maintain a safe environment, washing hands regularly is essential for general hygiene, and storing peanuts in a sealed container helps prevent contamination; however, these actions alone do not address the risk posed by residual allergens on surfaces where food is prepared.