The viral hoax about Mercadona's toxic shampoos: unjustified and alarmist
The importance of having healthy consumption habits to avoid pathologies and contribute to our general well-being is a lesson that, thanks to information technologies, we have learned well. But it is a two-sided coin: alarmist and wrong messages abound on social networks, often the result of a misunderstanding of the components of the products that generate chemophobia.
Thus, a post originating in a Facebook group at the end of January urges "not to buy", and even to "throw away" if we have it at home, an oil for infant hygiene sold in Mercadona under the Deliplus Hyppos Baby Care brand under the pretext that it contains paraffin. According to the text, the alert extends to "perfumes, shower gels, soaps, deodorants, shampoos, hand and body creams, etc...".
"This oil contains liquid paraffin, you are [sic] smearing your baby's skin with oil and on top of that they have the audacity to capitalize on PEDIATRIC COSMETICS" - the author denounces. She then details the evils attributed to this compound with a text copied from a website that was dedicated to marketing "organic cosmetics" products:
Paraffin is another of the toxic and dangerous ingredients used in industrial cosmetics. It is a set of hydrocarbons derived from petroleum that is extraordinarily cheap and is used to create a waterproof layer on the skin that gives it a soft and smooth appearance.
Another passage copied from an article in La Vanguardia abounds along the same lines: Putting paraffin on the skin is like putting plastic. Being so occlusive, it prevents the skin from breathing and plugs the pores, preventing the expulsion of contaminating agents out of our body. So, the more we use it to moisturize the skin, the more dehydrated it is and the more product we need. What the author of her own handwriting does add is that we cannot "metabolize" it.
What is true in all this? Little or nothing, according to Maldita Ciencia, a medium expressly dedicated to denying the scientific, nutritional and health misinformation that abounds on the networks. They are the ones who have brought this hoax to light, a classic case of what is considered cherry picking: focusing on a single aspect of a complex set and keeping only biased information.
Liquid paraffin, in fact, comes from oil, like so many other commonly used products. If the idea of "smearing" the skin and hair with it is alarming, we must think that it is also in some foods: it is used, for example, to cover apples to give them a shiny appearance, the famous "wax" that can be ingested without posing any risk to health.
"The characteristics of a substance do not depend on its origin but on its composition" - explained to EL ESPAÑOL Miguel Ángel Lurueña, Doctor of Science and Food and disseminator, to deny another hoax. "Chlorine is made in a laboratory and serves to make the water drinkable while poisonous mushrooms grow in the forest and can take you to the grave." The truth is that the use of liquid paraffin in cosmetics is regulated at state and European level, and it is considered safe in any quantity as long as it does not contain more than 0.005% impurities.
But, indeed, liquid paraffin is occlusive and prevents water from being lost through the pores. That is the reason why it is used in beauty creams to keep the skin hydrated and in lip Vaseline to avoid, for example, being "cut" when the cold air causes a sudden evaporation. On the other hand, the idea that they prevent "eliminating toxins" is based on another mistaken premise that feeds the erroneous 'detox fever': the filtration and elimination of toxic particles in our body is the task of the kidneys and the liver, not the skin .
Along the same lines, liquid paraffin has medical applications in case of constipation: it prevents stool from losing moisture through the intestinal walls and facilitates its evacuation. Finally, the main reason why it is used in cosmetic, food and health products is that there is no evidence that it accumulates in the body causing disorders, as the post states.
Thus, a meta-study based on 13 trials on humans and animals published in 2017 in Toxicology Letters concluded that mineral oils and waxes were only absorbed deep into the stratum corneum, the outermost layer of the epidermis. Furthermore, the penetration was "minimal" and did not significantly affect the body, so the consumption of substances such as liquid paraffin was considered "safe".