Not An Allergen.

Vibranium

This metal may be fictional, but it provides a great opportunity to look at what makes a substance more or less likely to be an allergen. Based on what we know of vibranium, we’d stand by: not a common allergen.

Our first justification is that vibranium is extremely rare, found almost exclusively in Wakanda. One factor that significantly increases the chances of something becoming an allergen is its ubiquity: the more it is present in things that we commonly use, the higher the chances of it eventually becoming a contact allergen.

Second: a key characteristic of vibranium is its ability to absorb sound waves, vibrations, and other kinetic energy in its own molecular bonds, dissipating the energy within its bonds instead of allowing them to penetrate through it or to destroy it. While there is a limit to how much energy vibranium can store, it does store what is acted upon it, i.e. it keeps the force it receives, which also prevents the force from transferring to the person behind or underneath it (why bullets seem to bounce off vibranium, as opposed to go through it, for example). An important trait of an allergen is ability to be absorbed by the skin. The smaller the molecular size of a substance, the more allergenic it potentially is. The larger the molecule and the less likely to be absorbed into the skin, the more potentially hypoallergenic it is. Vibranium’s ability to function as a barrier could be beneficial to skin, preventing contaminants from passing through it and coming into contact with skin.

Thank you to Artist (and mega Marvel and science fan) Risa Puno for pointing out the concern that breaking molecular bonds is an endothermic reaction (versus bond formation, which is exothermic). Assuming vibranium works by breaking bonds but somehow holding on to the particles so that they can re-form at a later time in order to release the energy, there could be a concern that the smaller molecules might get absorbed in the meantime into the material and therefore possibly come into contact with the skin underneath. This, however, could be mitigated if the intermolecular (or ionic) forces that are holding the smaller particles are enough to keep them from being absorbed. And this is where something from our current reality may come in handy, which is also our third justification for vibranium’s non-allergenicity.

Third: graphene and nickel. The closest substance we currently have to vibranium seems to be graphene, and some early studies show its ability to provide a barrier against metal corrosion, reducing the resulting release of nickel, a top allergen for skin. Nickel is one of the most widely-used metals in various products that come into contact with skin — everything from coins to zippers, dental equipment, cutlery, jewelry, and more. Interestingly, when skin that is sensitive to nickel comes into contact with it, an immune response is triggered (an inflammatory reaction)…but what is particularly problematic is that nickel is dissolved by sweat, resulting in its absorption and penetration into the skin, which causes the allergic reaction. In fact, nickel is far less of a problem if it is bonded powerfully to a material, preventing its coming off when in contact with skin — which is why many people who are allergic to nickel can actually use stainless steel, for example, as long as it is of very high quality (meaning the nickel is bonded to it extremely well and does not come off when in contact with skin).

According to a study* on graphene applied to nickel as a protection barrier published in the peer-reviewed journal Materials, graphene seems to prevent this solubility of nickel:

“graphene coatings act as a protective membrane in biological environments that decreases microbial corrosion of Ni and reduces release of Ni2+ ions (source of Ni allergic contact hypersensitivity) when in contact with sweat. This performance seems not to be connected to the strong orbital hybridization that Ni and graphene interface present, indicating electron transfer might not be playing a main role in the robust response of this nanostructured system. The observed protection from biological environment can be understood in terms of graphene impermeability to transfer Ni2+ ions, which is enhanced for few layers of graphene grown on Ni.”

If vibranium is closest to graphene in real life, and early evidence shows graphene’s ability to effectively prevent the corrosion of nickel (one of the most common skin allergens) when it comes into contact with skin, vibranium could (theoretically) absorb and nullify allergens while ensuring their non-penetration to the underlying skin, making it an excellent protective barrier against allergic reactions.

While there may be concerns in its fictitious world regarding the radiation vibranium emits, if we’re taking purely contact allergens, vibranium’s rarity and barrier qualities would seem to make it a strong candidate for non-allergenicity. At least until Wakandan dermatological experts  — or their counterparts in ACDS, ESSCA, and other contact dermatitis groups — rule otherwise!

Sources:
*Parra C, Montero-Silva F, Gentil D, et al. The Many Faces of Graphene as Protection Barrier. Performance under Microbial Corrosion and Ni Allergy Conditions. Materials. 2017;10(12):1406. doi:10.3390/ma10121406.
Shideh Kabiri Ameri et al. “Graphene Electronic Tattoo Sensors.” ACS Nano. DOI: 10.1021/acsnano.7b02182
Gibbens, S. Black Panther’s Secret Weapon Explained. (2018, February 16). National Geographic.
Logan, M. What’s the Closest Real-World Material to Black Panther’s Vibranium? (2018, February 18). Inverse.
Vibranium. Marvel Wikia.
Wikipedia contributors. (2018, April 10). Vibranium. In Wikipedia, The Free Encyclopedia. Retrieved 03:34, April 14, 2018.
Vibranium. Marvel Cinematic Universe Wikia.

 If you have a history of sensitive skin in real life, don’t guess: random trial and error can cause more damage. Ask your non-fictional superhero dermatologist of choice about a patch test.

For more:

On the prevalence of skin allergies, see Skin Allergies Are More Common Than Ever and One In Four Is Allergic to Common Skin Care And Cosmetic Ingredients.

To learn more about the VH-Rating System and hypoallergenicity, click here.

References (Nonfictional): 

Regularly published reports on the most common allergens by the North American Contact Dermatitis Group and European Surveillance System on Contact Allergies (based on over 28,000 patch test results, combined), plus other studies. Remember, we are all individuals — just because an ingredient is not on the most common allergen lists does not mean you cannot be sensitive to it, or that it will not become an allergen. These references, being based on so many patch test results, are a good basis but it is always best to get a patch test yourself.

12. Marks JG, Belsito DV, DeLeo VA, et al. North American Contact Dermatitis Group patch-test results, 1998 to 2000. Am J Contact Dermat. 2003;14(2):59-62.
13. Warshaw EM, Belsito DV, Taylor JS, et al. North American Contact Dermatitis Group patch test results: 2009 to 2010. Dermatitis. 2013;24(2):50-99.