What does the 'May Contain' statement on pack really mean?

It means the product in question may contain the ingredients listed in this statement, typically as a result of what is called 'cross-contamination'. For example, we may process a product containing peanuts and the machine is completely cleaned prior to the next product being manufactures, we cannot completely be certain that some residue of the peanut may remain. So the 'May Contains' statements help people who suffer from all types of food allergies to make safe and informed decisions about products.