Sodium hydroxide is an ingredient found in many household products, from beauty and personal care, to cleaning products and even industrial solvents. When it comes to your beauty regimen, it’s usually hiding in your moisturizers, makeup, shaving foam, shampoo, hair dye, hair removal, sun tanning products, and more.
But despite its universal usage, it may surprise you to learn that sodium hydroxide — commonly known as caustic soda or lye — can actually be an irritant! Thanks to its ability to dissolve grease, fats, and oils, it’s not uncommon to find this ingredient in soaps, detergents and even drain cleaners.
But don’t panic… here at Cel, we’ve dived into the science behind the sodium, so you know how and why it’s safe in skincare.
Fortunately, with the aid of some simple chemistry, it is easy enough to make sense of the role sodium hydroxide plays in our favorite beauty products, and whether or not you should be concerned about it.
What Exactly Is Sodium Hydroxide?
Sodium Hydroxide (NaOH) is what is known as a soluble inorganic compound, made up of sodium (Na+), and hydroxide (OH-). What’s interesting is that the amount of sodium hydroxide you put in to a product, is not necessarily the same amount present in the end result. This is because sodium hydroxide, when dissolved in water, breaks up or ‘dissociates’. This results in separate sodium ions and hydroxide ions.
Sodium ions are relatively nonthreatening. These are the exact same as those found in table salt, in seawater, and even in your own sweat! So nothing to worry about in skincare! While the sodium ions are harmless, the hydroxide ions play a much more active role. Ultimately, this is the reason sodium hydroxide is added to so many products, due to its ability to balance pH levels.
In water-based products, high levels of hydrogen result in high levels of acidity. The addition of hydroxide can turn excess hydrogen into a neutral solution, making it safe to use. This is its main function in your beauty products! When adding sodium hydroxide, most of the hydroxide ions will neutralise and turn to water, meaning that the levels of hydroxide in the solution is decreased and should no longer pose a threat. Meanwhile, the sodium ions simply float away.
So, It’s Safe?
Enough of the science lesson! Yes, if you see Sodium Hydroxide on the ingredients list of your favourite cleanser or skincare product, there’s no need to be alarmed! It’s FDA approved, and usually there to maintain a safe pH level in the product itself.
However, if you have sensitive skin, it’s still worth avoiding sodium hydroxide in your skincare products wherever possible – after all, it’s hard to tell the quantities when looking at a label! To ensure that all of our skincare products can be used by all skin types, we've avoided this ingredient, meaning that no matter how sensitive your skin, you can trust Cel’s products won’t cause irritation!