“Allergy tested. 100% fragrance free.” This guarantee should have spared me the torture of a painful allergy-related facial rash. But sadly, this Clinique slogan proved to be as empty as political campaign promises when one of its Chubby Stick colored lip balms left me with nearly two weeks of misery, thanks to irritant/allergic contact dermatitis.

A few years ago, I zeroed in on mangoes as an unfortunate allergy after suffering from countless bouts of a mysterious contact allergy that led to dry, cracked, burning lips. Hypersensitivity to mangoes can come in all different varieties, but the variant I found myself bestowed with was delayed hypersensitivity in the form of a contact dermatitis. Exposure to the urushiol oils found in mango peels, pulp, and seeds is the most common explanation for this resulting allergic reaction, and like clockwork, two-three days after exposure, the symptoms begin to appear. After accepting my position as the world’s most miserable South Asian, I had proceeded to avoid all mango-based products.

Unfortunately, depriving myself of mangoes, mango juice, mango chutneys, mango ice cream, and all other delicious mango-flavored things, it didn’t matter when I ended up with the dreaded “mango mouth” after trying out the Chubby Stick that had arrived in my monthly Birchbox. Imagine my surprise when a one-time use of this allegedly allergy-tested lip balm led to such significant consequences right before my week of vacation. Hindsight is 20/20 of course as, after the fact, I realized that the lip balm is loaded with mango butter.

I can only imagine what other allergens may be lurking in some seemingly safe cosmetics if even allegedly allergy-tested products can cause such severe reactions.

A large scale study using data from the North American Contact Dermatitis group found that 21.8 percent of patients studied suffered from a cosmetic-related allergic reaction. Where exactly the reaction occurred differed between men and women, but not so surprisingly, females had much higher head and neck involvement than men. The debilitating nature of facial contact dermatitis will never fully be understood by those who have been lucky enough to avoid these types of reactions. Inability to speak, laugh, or smile as usual when the rash affects one’s mouth along with personal embarrassment at the external appearance of facial rashes can significantly affect quality of life—particularly given that the treatment for contact dermatitis is mostly supportive (read: “time will heal”) while the reaction runs its course.

The most commonly offending allergens in cosmetics have been found to be preservatives, fragrance mixes, and para-phenylenediamine (PPD), an ingredient often found in cosmetic dyes. The task of identifying allergic reaction-inducing ingredients is not an easy one, especially given that almost all of them have names as long as para-phenylenediamine. A leading dermatology textbook identified quaternium-15 as the most common cosmetic preservative known to cause allergic contact dermatitis. This formaldehyde-releasing ammonium salt can be found in everything from foundation, blush, and eye makeup, to certain shampoos and facial cleansers. So while formaldehyde itself is now rarely used in personal care products, chemicals like quaternium-15 are closely related to formaldehyde and cause similar allergic reactions.

As for fragrances and fragrance mixes, the identification of those allergens can be even more difficult. Most commonly seen to be associated with fragrance allergies is balsam of Peru, a resin that comes from Myroxylon balsamum tree bark. A positive patch test to balsam of Peru guarantees a fragrance allergy. Most people with this sensitivity will be better off sticking with completely fragrance-free products so as to avoid the eyelid dermatitis that is often associated with this balsam of Peru allergy.

My reading uncovered a few other allergens that I never would have even guessed could be in cosmetics, including cobalt and propylene glycol (yes, the same thing is in antifreeze). Given my own experiences with a terrible facial rash at the hands of a lip balm, it was also disturbing to discover that the secret ingredient for the very popular Burt’s Bees line of “all natural” lip balms—beeswax—contains propolis, an allergen also well known to cause inflammation of the lips and other reactions in susceptible people. It goes without saying that while chemicals can cause allergic reactions, so can all these natural products, and labels of “natural” or “allergy tested” do not make products any safer for at-risk groups.

Customer service representatives at Clinique noted my “mango mouth” complaints and assured me that this case of sensitivity would eventually reach company higher-ups. I can only hope that a company that prides itself on allergy testing will take this matter seriously. Birchbox cannot tailor my monthly subscription to my sensitivity to certain allergens, so I will be practicing due diligence with all products that get shipped my way.

And now that I have learned my lesson the hard way, I would encourage everyone to do the same conscious ingredient checking with any new personal care or cosmetic product they plan on using.