1. Alcohol
It is true that ethanol (also called ethyl alcohol) should not be applied directly to the skin. Ethanol is not recommended even for the oiliest skin types, because skin will respond to such drying shock by producing even more oil.
 
However, there has never been a proven link between topical ethanol use and skin cancer. Nor has ethanol ever been proven to cause oxidative damage within the skin. In truth, ethanol can be quite beneficial in skincare products, as it dries out layers of product, compressing ingredients like silicones into a form that’s faster-drying and deeper-penetrating. 
 
2. Parabens
Parabens are preservatives, and have been proven to reduce bacterial and fungal growth in skin care and cosmetics. Unlike many other preservatives, parabens applied directly to the skin have a low risk of a form of irritation known as contact dermatitis, according to the American Journal of Contact Dermatitis. However, many consumers believe that parabens may cause cancer, influence estrogen levels, accumulate in tissues, and increase UVB-mediated DNA damage.
 
These studies stem from research showing that parabens bind to estrogen receptors in certain types of breast cancer cells and the uteri of rats. However, many of these animal studies don’t apply to humans, which is the true reason why the FDA continues to allow parabens in skin care and cosmetics products. For instance, in one study, breast cancer cells were subjected to parabens in concentrations that were tens of thousands of times beyond what someone would be subjected to from skin care and cosmetics.
 
Even if parabens do accumulate in tissues over time, as suggested by a 2007 study, this effect would last no longer than three years—still far lower than the amounts of parabens used in the animal studies. I personally worry far more about the potential bacterial or fungal growth and irritation from alternative preservatives. But, alas, for those who believe in a “better safe than sorry” approach, paraben-free products will continue to proliferate.
 
3. Petrolatum
Petrolatum is an occlusive agent, meaning that it traps moisture within the skin. This property makes petrolatum-containing products perfect to use after a bath or shower, or overnight with 100 percent cotton socks.
The web looms with concern that petrolatum interferes with hormone production, causes cancer, and clogs the pores. However, none of these are true. Petrolatum used in skin care products is cosmetic-grade, meaning that it is highly refined and purified from crude oil products before it is incorporated into beauty products.
 
One valid concern about petrolatum is that it is from a non-renewable source. That’s true. However, as cosmetic chemist Rebecca James Gadberry has noted, many people do not realize that more than 50 percent of the ingredients used in cosmetics are derived from non-renewable resources.
 
Another valid concern of petrolatum is that you have to be careful what else you use with it. For instance, lanolin can clog the pores. Applying a lotion with lanolin followed by one with petrolatum may clog the pores further, as petrolatum traps the other ingredients into the skin. For what else should not be used with petrolatum, check out this list of comedogenic (pore-clogging) ingredients.
 
4. Mineral Oil
No one screams that mineral oil will cause cancer or affect hormone production, but there is a widespread belief that it clogs the pores. Like petrolatum (from which mineral oil is derived), mineral oil is an occlusive agent. It again will trap other ingredients and moisture into the skin. For this reason, mineral oil should also not be used in leave-on treatments containing comedogenic (pore-clogging) ingredients. However, as long as these ingredients are avoided, mineral oil is a superior moisturizing ingredient, filling the spaces between skin cells (called corneocytes) to create a smooth surface. Mineral oil also has a low risk of irritation and has better moisturizing ability than the fatty acid linoleic acid.
 
Bottom Line
The real dangers in skin care are not alcohol, parabens, petrolatum, or mineral oil, despite what others may lead you to believe. While those within the green community may dislike petrolatum and mineral oil because they are derived from non-renewable resources, the claims that any of these ingredients cause cancer, affect hormone production, or exacerbate signs of aging in humans are largely unfounded. I personally feel these ungrounded concerns and the lean towards “natural/organic” and “paraben-free” are holding the beauty industry back from true progress in the form of stem cells, DNA-targeted treatments, and more invasive treatments. Nonetheless, as long as rumors like these prevail, we will be stuck revising unnecessarily rather than moving forward.