Sulfates are aggressive detergents made of sulfur-containing mineral salts. You'll see them identified on labels as sodium lauryl sulfate, sodium laureth sulfate or ammonium lauryl sulfate. Sometimes, they're referred to as "SLS" and/or "ALS" for short.
First introduced into modern hair care in the 1930’s, sulfates revolutionized the health and beauty industry. Prior people relied on simple (but not always effective) soaps to clean their skin and hair. Sulfates are powerful, inexpensive and easy to acquire. Also they are responsible for the foaming lather we’ve come to associate with being clean. Today it’s one of the most common chemicals used in our households but we are beginning to understand that sulphates have an impact on our health and beauty.
How Sulfates Work
Sulfates are an additive to cleaning products that causes the foaming action commonly associated with soaps. The most common sulfate is sodium lauryl sulfate (SLS), found in most shampoos and conditioners #haircare. Used primarily as a foaming agent, a sulfate combines with water to emulsify grease, dispersing it into the water so that it can be washed away. Sulfates also act as a surfactant, a substance that reduces the surface tension of water, helping your shampoo loosen the grease and sebum from your hair and scalp. While some studies have linked sulfates to cell damage, sulfates are considered safe in concentrations below 1 percent or when used for short periods of time, according to the Journal of the American College of Toxicology.
Keep in mind a shampoo that contains sulfates typically has a concentration of around 15 percent.
Sulfates and Your Hair and Scalp
Our skin and hair are part of our natural living ecosystem known as the biome – and sulfates disrupt its delicate balance. Here’s how:
Sulfates wash away the natural anti-microbial peptides, proteins, and water-proofing oils our biomes create. Without these health-preserving substances, our hair and scalp are stripped of vital moisture, exposed to harmful microbes, allergens and environmental pollution and vulnerable to damage, infection and illness.
Sulfates lift the cuticle of the hair. The outermost layer of the hair shaft is a series of hard-shelled, overlapping hair cells called the cuticle. They lay flat, like shingles on a roof. Owing to the reduced surface tension, sulfates work their way under the cuticle, making it lift and buckle. This exposes the cortex of the hair to moisture, which causes frizz #frizzyhair, or to arid air that can cause dryness #dryhair. The compromised cuticle and cortex weakens the entire hair strand, making it dull and prone to damage, breakage and split ends.
Sulfates make your hair take longer to dry. When the cuticle is lifted, more moisture is absorbed into the cortex, which then takes up to twice as long to dry. If you are using a hair dryer, that’s twice as much heat exposure on an already-compromised hair strand.
Sulfates leave an anionic charge. Sulfates have a negative electric charge – and that charge remains on your hair and scalp when you rinse the shampoo away. This leaves a dulling residue and can cause static and flyaways. To neutralize this film, the hair must then be coated with a synthetic, silicone-based conditioner (more chemicals), which masks the damage with an artificial shine.
Sulfates cause scalp irritation. Since sulfates strip the natural lipids off the scalp #scalpirritation, its natural water barrier is broken. Chemicals from products can then permeate the top layers of skin, causing irritation and inflammation. Meanwhile, the underlying layers of skin are exposed to pathogens (disease-causing bacteria) that otherwise wouldn’t be able to get there.