4. If any ingredient has a ‘may contain’ warning tell any customer who wishes to know. The warning shows there may be cross-contamination.
5. Always be truthful. You can recommend a safe alternative or even prepare something from scratch to avoid the possibility of cross-contamination.
6. The customer decides. Once you have told the customer about the ingredients and the possibility of cross-contamination, the customer can make the final decision whether or not to buy the food.