How can there be a warning on a package for an ingredient that is not in the ingredient list?

The ingredient list on a product's packaging must state the INCI names (official description assigned by the European Commission) of each ingredient. Ingredients are frequently better known to the consumer by their chemical name.

For example, a product that contains the UV filter Benzophenene-3, will state this, the INCI name, on the ingredient list. All products containing this ingredient require a warning alerting the consumer that this ingredient can, in some cases, can cause a photoallergy. Because the ingredient is more commonly known by its chemical name Oxybenzone, the warning will refer to Oxybenzone and not Benzopheneone-3.