Generally speaking, allergens are not intentionally introduced into the formulas. These are substances naturally present in many essential oils, perfumes, etc. These molecules come from the fragrance of the products, which are 100% of natural origin. Registration on the INCI list is mandatory because these substances are among the 26 allergens for which there is a labeling obligation, in order to inform people potentially allergic to this molecule. For people who are not allergic to them, these substances are safe. For example, limonene is found naturally in citrus fruits. Do you have any doubts? Do not hesitate to test the product in the inner crease of the elbow before applying it to the rest of the face or body.