What Is the Difference Between SLES and SLS?

Sodium Lauryl Ether Sulfate (SLES) and Sodium Lauryl Sulfate (SLS) are both surfactants commonly used in various personal care and cleaning products, but they have some differences in their chemical structures and properties.

1. Chemical Structure:
– Sodium Lauryl Ether Sulfate (SLES): SLES is an ethoxylated compound, meaning it has undergone ethoxylation, a chemical process that involves adding ethylene oxide molecules to the parent compound. This results in a molecule with an ether chain. The number of ethylene oxide units added can vary, resulting in different variations of SLES with different chain lengths.
– Sodium Lauryl Sulfate (SLS): SLS, on the other hand, does not undergo ethoxylation. It is a simple sulfate salt derived from lauryl alcohol.

2. Foaming and Cleansing Properties:
– SLES: SLES is known for its foaming and cleansing properties. It produces a rich lather and effectively removes dirt, oil, and other impurities from the skin or hair.
– SLS: SLS is also a foaming agent and provides good cleansing abilities. It is often used in products that require high foaming, such as shampoos, toothpaste, and body washes.

3. Mildness:
– SLES: Compared to SLS, SLES is generally considered milder on the skin. The ethoxylation process makes the molecule less harsh and reduces its potential to cause skin irritation. However, some individuals with sensitive skin may still experience irritation or dryness with SLES-containing products.
– SLS: SLS, in its pure form, can be more irritating to the skin and scalp, especially when used in high concentrations or on sensitive skin. It may cause dryness, redness, or itching for some people.

4. Environmental Impact:
– SLES: SLES is generally considered to have a lower environmental impact compared to SLS. The ethoxylation process makes SLES biodegradable and less persistent in the environment.
– SLS: SLS is also biodegradable, but it may persist in aquatic environments and can be toxic to aquatic life in high concentrations.