Question

to prevent food allergens from being transferred to food, buy food from an approved reputable supplier. store food and chemicals separately. avoid pewter tableware and copper cookware. clean and sanitize utensils before use.

Explanation:

Cleaning and sanitizing utensils before use helps remove any residual food allergens that could be transferred to new food. Buying from a supplier is about source - safety, storing food and chemicals separately is to prevent chemical contamination, and avoiding certain cookware is related to metal - leaching risks, not directly to allergen transfer prevention.

Answer:

clean and sanitize utensils before use.