The History Of Sulfates In Hair Care Products
People have been using shampoos since the mid 1800s. These were simple formulas of traditional bar soap and water with herbs for fragrance. By the turn of the 20th century, liquid shampoo similar to what we use today became commercially available and chemists like me began trying to perfect its uses.
In 1930, Procter & Gamble created the first shampoo that used a sulfate base, forever changing the world of hair care. Royal Drene Shampoo was so important to the hair care industry that a bottle of it still sits in the Smithsonian Museum.
Sulfates or no, these bottles are fab!
Today, sulfates are still far and away the number one ingredient used in hair care products. But, as with everything, there are pros and cons. I will attempt to show both when it comes to choosing your next shampoo.
When a product claims to be “sulfate-free,” it's typically free of one of three commonly used compounds in shampoo: Sodium Laureth Sulfate, Sodium Lauryl Sulfate, or Ammonium Laureth Sulfate. In the industry, these compounds are known by the acronyms SLES, SLS, and ALS, respectively.
What Are Sulfates And What Do They Do?
Sulfates are all primary surfactants. A surfactant is a mixture of molecules that can attract both water and oil. This unique property allows soaps, shampoos, and body washes to separate dirt and oil from your skin or hair and then allow the water you rinse it with to carry it off your body and down the drain.
Without these ingredients, cleansing products wouldn’t work nearly as well as they do. Sulfates in particular are very good at doing this; sometimes they're so good that they can strip your skin of natural oils and proteins that help keep it healthy. It's all according the formulation, but more on that later.
Let's continue to nerd out on sulfates, shall we?
Sulfates can be naturally derived or synthetic. For example, SLS is made using lauric acid as a starting material. The lauric acid can come from coconut oil, palm kernel oil, or petroleum, all of which contain a high quantity of lauric fatty alcohol.
After you collect your fatty alcohol, you proceed by reacting the lauryl alcohol with sulfur trioxide gas. It is then neutralized with sodium carbonate (natural). So, long story short, sulfates are Sulfur and Oxygen combined, and the rest of the molecules are the fatty acid, which come from coconut or palm oil.
Sulfur + Oxygen + Fatty Oil (Palm/Coconut Oil) = SLS (aka “Sulfates”)
Are Sulfates Safe? Will They Dry Out Your Hair?
First things first, sulfates don’t cause cancer! There is no evidence that suggests they have anything to do with cancer. Here is what the American Cancer Society has to say about it. And here is an interesting Snopes article that points to an internet origin of this myth dating back to 1998.
But if there are no cancer risks, why do people use sulfate-free products? Well, sulfates can be irritating (many surfactants are). The key attribute that makes them good at removing dirt also makes them good at stripping away protective oils. But as far as safety is concerned, the CIR (Cosmetic Ingredient Review) has reviewed it and found it to be safe if used in rinse-off products: “Sodium Lauryl Sulfate and Ammonium Lauryl Sulfate appear to be safe in formulations designed for discontinuous, brief use followed by thorough rinsing from the surface of the skin.”
Sulfates don’t cause cancer! There's no evidence that suggests they have anything to do with cancer.
Sulfates are safe but that doesn’t mean they're non-irritating. Get sulfate shampoo in your eyes and it will really sting. In addition to being an irritant, another downside of using sulfates is that they can dry out your hair and skin. Sulfate-free formulas can be milder because they don’t strip the natural oils out of your skin as much.
As far as performance, dollar to dollar, you can’t beat sulfates for cleansing and foam. Foam is not a necessity for cleaning, but numerous consumer studies (including ones my formulas have undergone) show again and again that most people prefer a shampoo that provides copious amounts of foam.
Recently, as consumers ask for sulfate-free formulas, we chemists have to be creative with other alternatives. The following are milder alternatives to look for in your next sulfate-free shampoo:
- Sodium Cocoamphoacetate• Cocamidopropyl Betaine• Lauryl Glucoside• Coco Glucoside• Disodium Laureth Sulfosuccinate• Disodium Lauroamphodiacetate
Unfortunately, even sulfate-free shampoos will also strip your hair of oil. This is because all shampoos strip your hair of natural oil. That’s how they clean. If you are concerned about losing your hair's natural oils, the only thing you can do is stop washing your hair. But I wouldn’t get too attached to your natural oils, because they capture dirt, pollen, and pollution, which we definitely don't want in our hair. To keep your hair clean and conditioned, formulators add conditioning agents such as:
- Guar Hydroxypropyltrimonium Chloride (polymer)• Dimethicone (silicone)• Quaternium 80 (quaternary agent)
These ingredients are designed to be left behind on your hair shaft after you rinse away the dirt and grime. The different types of ingredients used can modify how your hair feels, looks, and styles. Because of these differences, chemists test their shampoos and conditioners frequently and often employ hair stylists to get their expert opinions on how newly washed hair feels and looks.
Sulfates are used in many personal care products and are some of the most effective ingredients you can use for cleaning. They often get bad press and the natural crowd hates them, but they are perfectly fine ingredients. Remember, ultimately you are the judge of what works best for your skin and hair type, but now you can look past scare tactics and really base your opinion with a little more science.