Oct 20

Oct 20 Preservatives In Skincare

Are preservatives good or bad? It depends.

The Role Of Preservatives In Skincare

Preservatives in skincare kill microbes so that products do not become contaminated and make us ill. They also extend the shelf life of products.

Are Preservatives Necessary?

In some products, preservatives are absolutely necessary and the product would be dangerous without them. Formulas that require preservatives are those that contain water and/or are likely to come in contact with water. Water provides an ideal environment for bacteria and mold to grow.

In contrast, a body oil that is oil-based and does not contain any water may not require a preservative system.

Additionally, certain products that have a ph that is really high or really low may not require preservative systems because bacteria will not grow in these conditions. Some soaps might fall into this category.

Packaging plays a role in preservative needs as well. For example, a tub has a greater chance of contamination compared to an airless tube, where the formula inside the bottle does not come in contact with skin or water.

Preservatives & The Skin Microbiome

Preservatives in skincare have been found to impact the skin microbiome. In this recent study on preservatives in cosmetics, preservatives were shown to inhibit survival of the nine types of bacteria tested.

There is evidence that healthy skin has higher microbial diversity than unhealthy skin. Certain bacteria on our skin actually help keep us healthy and are our first line of defense against “bad bacteria.” For example, staphylococcus epidermidis provides protection against pathenogenic bacteria.

Knowing that preservative systems have an impact on the skin microbiome, consider using some skincare products that do not require preservatives. Equally important is understanding which specific preservatives to look out for and avoid.

Harmful Preservatives

Not all preservative systems are created equally safe. After being used for years, many have been found to be unsafe and are linked to adverse health effects. Here is a list of commonly used harmful preservatives and why you should avoid them:

DMDM hydantoin - a formaldehyde-releasing preservative that can cause skin sensitivity or irritation and is associated with contact dermatitis. Formaldehyde is a carcinogen, neurotoxicant, and causes immunotoxic effects. Lawsuits have been brought against brands using dmdm hydantoin, linking the preservative to hair loss. [1]
Parabens – routinely used as antimicrobial preservatives in everyday products from cosmetics, skincare, and household products to pharmaceuticals and food and beverage processing. Personal care products (including cosmetics) are one of the largest contributors to our exposure of parabens. A Study from the University of California Berkeley found an earlier onset of puberty in girls associated with higher paraben levels. Parabens are immune and skin toxicants, they mimic estrogen and disrupt the endocrine system, are toxic to the developmental and reproductive systems, interfere with gene expression, and are associated with cancer. Children exposed to propylparaben in the womb may be at a higher risk of obesity. [2]

BHT - an antioxidant and preservative used in food and cosmetics that has been associated with endocrine disruption. BHT is similar to butylated hydroxyanisole (BHA) but does not show the same carcinogenic effects.[3]
BHA - an antioxidant and preservative used in food and cosmetics. The U.S. National Toxicology Program has classified it as "reasonably anticipated to be a human carcinogen." BHA might also have endocrine disrupting effects.[4]

Phenoxyethanol - while it can be found naturally in green tea, phenoxyethanol is created synthetically in a lab for use as a preservative in cosmetics and personal care products. Phenoxyethanol is made from the reaction of ethylene oxide, phenol and an alkali. Ethylene oxide on its own is a carcinogen, and it is associated with reproductive effects. Phenol is a toxic powder created from benzene, which is a carcinogen. Because phenoxyethanol is an ethoxylated ingredient, it can contain the carcinogenic contaminant 1,4-dioxane and residual ethylene oxide. In 2008 the FDA warned consumers not to use Mommy’s Bliss Nipple cream because it contained phenoxyethanol which was harmful to infants. The statement indicated phenoxyethanol could “depress the central nervous system and may cause vomiting and diarrhea, which can lead to dehydration in infants.” Additionally, studies suggest phenoxyethanol may affect ovarian function as increased phenoxyethanol metabolites in urine is associated with longer time to pregnancy. [5]
Diazolindyl urea - a formaldehyde-releasing preservative. Formaldehyde is a carcinogen and neurotoxicant. Diazolindyl urea can cause skin irritation and is associated with neurotoxicity in animal studies. [6]

Quaternium 15- a formaldehyde-releasing preservative that is a contact sensitizer. Formaldehyde is a carcinogen and neurotoxicant. Quaternium 15 is banned in cosmetics in the EU. [7}

References:

[1]

https://www.cosmeticsinfo.org/ingredient/dmdm-hydantoin

https://reader.elsevier.com/reader/sd/pii/S157821901170765X?token=0992F3E4CDC6E546F72591EE2ACF8261DC9A8A5A7A5CFB74419A1ADB27CA92DE0D07EFC35ABA43A7FBB95175CF440ACA&originRegion=us-east-1&originCreation=20211008202114

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6477564/#ref24

https://onlinelibrary.wiley.com/doi/10.1111/jnc.12356

https://www.aboutlawsuits.com/johnson-johnson-ogx-shampoo-cancer-lawsuit-185774/

[2]

https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/10.1002/jat.3027

https://academic.oup.com/humrep/article/34/1/109/5204432

https://news.berkeley.edu/2018/12/03/prenatal-exposure-to-chemicals-in-personal-care-products-may-speed-puberty-in-girls/

https://www.sciencedirect.com/science/article/abs/pii/S0303720718301060?via%3Dihub

https://www.mdpi.com/1660-4601/18/4/1796

[3]

https://www.sciencedirect.com/science/article/pii/S0160412018326722

https://endocrinedisruption.org/popup-chemical-details?chemid=907