What Is Sodium Chloride?
Sodium chloride, more commonly known as table salt, is not a skincare ingredient that you may expect to see in your product but sodium chloride functions as a binder, oral care agent, gentle abrasive, thickener, and preservative in a variety of cosmetics and skincare products.
Sodium chloride is an ionic compound with the chemical formula NaCl. You are most likely familiar with sodium chloride in its edible form as table salt, which is used as a condiment, baking ingredient, and food preservative. Additionally, sodium chloride is the salt that contributes to the salinity of seawater, as well as the extracellular fluid of many multicellular organisms. Salt is an important part of the healthy functioning of the body.
the good:Sodium Chloride helps to improve the texture and stability of formulations.
the not so good:Doesn’t provide any specific benefits directly to the skin as it is mainly used to improve the longevity and feel of the product.
Who is it for?All skin types except those that have an identified allergy to it.
Synergetic ingredients:Works well with most ingredients
Keep an eye on:Nothing to keep an eye on here.
Why Is Salt Used In Skincare?
Sodium chloride is a multifunctional ingredient used in cosmetics and skincare products as a binder, oral care agent, gentle abrasive, thickening agent, and preservative.
A binder is a substance that absorbs water, swells, and helps to hold other ingredients together. Therefore, as a binder, sodium chloride functions to prevent other ingredients used in a cosmetic formulation from coming apart.
You’ll find sodium chloride in products like toothpaste and mouthwash due to its ability to cleanse the teeth and mouth, as well as reduce oral odor. Additionally, sodium chloride is a gentle abrasive, so it can effectively polish the teeth. Sodium chloride also imparts a flavor or a taste to a product.
Since sodium chloride exists as small crystals, this ingredient can function as a gentle abrasive in products like body and face scrubs. These products will help to exfoliate the top layers of skin, removing makeup, excess oil, dirt, and other impurities that may have accumulated during the day. Exfoliating is crucial in order to maintain clear skin since the build-up of extra dead cells on the skin’s surface can clog pores, eventually turning into undesirable breakouts or other dermal-related conditions. Furthermore, exfoliating becomes even more important as we age since the skin’s natural cycle of shedding dead cells slows down.
Another function of sodium chloride in cosmetics and personal care products is as a thickening agent. Thickeners are used to provide the products with the desired consistency. Sodium chloride can support the thickening effects of other thickeners.
Finally, sodium chloride is effective as a preservative due to its ability to reduce the water activity of foods. The water activity of a food is the amount of unbound water available for the growth of bacteria. The ability of sodium chloride to decrease water activity is thought to be due to the ability of sodium and chloride ions to associate with water molecules. This same mechanism can be utilized to preserve cosmetic products. Just like food, cosmetics products can become contaminated without preservatives, leading to product spoilage and possibly irritation or infections. Microbial contamination of products, especially those used around the eyes and on the skin, can lead to significant problems. Preservatives help prevent such problems, as well as extend the shelf-life of products.
Is Salt Safe?
The US Food and Drug Administration (FDA) includes sodium chloride on its list of substances considered Generally Recognized as Safe.
The Cosmetic Ingredient Review (CIR) Expert Panel, a group responsible for evaluating the safety of skincare and cosmetic ingredients, has deferred the evaluation of this ingredient because the safety has been assessed by the FDA.
References:Jantsch, J, 2015. ‘Cutaneous Na+ storage strengthens the antimicrobial barrier function of the skin and boosts macrophage-driven host defense’, Cell Metabolism, vol. 21, no. 3, pp. 493-501.