Pick up almost any dishwashing liquid, flip it over, and you’ll spot two similar-looking acronyms: SLS and SLES. They look like twins, and they’re certainly related. But they don’t behave the same way, and the difference starts with a bubble.
So why do we even need bubbles?
Grease and water don’t mix. That’s the problem every dishwashing liquid has to solve. The answer is surfactants, which are clever molecules with two ends: one that loves water and one that loves oil. The oil-loving end grabs onto grease, the water-loving end stays in the water, and together they pull grime off your plate so it can rinse away. The bubbles are a handy side effect of surfactants at work.
Meet the relatives
SLS is sodium lauryl sulfate. SLES is sodium laureth sulfate. The extra “eth” comes from a process called ethoxylation, which adds a short chain to the molecule. It’s a tiny change, but it makes SLES noticeably milder. Think of SLES as SLS with its edges softened.
Which one do we use, and why?
SLES gives strong grease-cutting and great foam with less potential to dry out or irritate skin. SLS is the more aggressive cleaner. For products that spend a lot of time on your hands, like dishwashing liquid, SLES is the better pick, which is why it’s our everyday choice.
We do use SLS in one place: our stain remover. It’s used in small amounts on a specific spot, where the stronger cleaning power helps and skin contact is brief. The right ingredient, in the right amount, for the right job.
Our SLES and SLS are both plant-derived, meaning the fatty alcohols they’re made from come from plant oils, such as coconut oil, rather than from crude oil. The molecules work exactly the same way as their petrochemical-derived twins, but they start from a renewable source instead of a fossil one.
So why does SLES have a bad reputation?
There are a few reasons, and each has a grain of truth.
Name confusion. SLES and SLS get lumped together, so worries about SLS stick to SLES too.
Irritation. Like many cleaning ingredients, SLES can be drying or irritating at high concentrations, which is why we’re careful about how much we use. The SLES in our products is plant-derived, which gives it a renewable starting point, but the molecule itself works the same way whatever its source. For extra gentle care, our Sensitive Dishwashing Liquid contains no SLES.
Dioxane. In early manufacturing, ethoxylation could leave behind a by-product called 1,4-dioxane. It’s a known issue, but processes have been refined and levels are now very low, below 10 parts per million.
Dose matters
Here’s the key idea: the dose matters. Think of chilli. A pinch gives your dinner a pleasant kick, but a spoonful of the concentrated stuff will make your eyes water. It’s the same plant and the same ingredient, and the only difference is how much of it you get.
Cleaning ingredients work the same way. The irritation concerns relate to high concentrations, not the small, diluted amounts in a finished product that gets rinsed off.
Where does it come from?
SLES can be made from fatty alcohols sourced from petrochemicals or from plant oils - we use the ones made from plant oils! The molecule works identically either way, but the SLES we use is plant-derived, so it starts from a renewable source instead of a fossil one. It’s also readily biodegradable according to Australian Standard AS4351, meaning microorganisms can break it down after it’s done its job.
The bottom line
SLES and SLS are close relatives, but SLES is the gentler one, which is why it’s our go-to. SLS earns a place in small, targeted amounts, like in our stain remover. For both, dose matters more than the name on the label.
Prefer to avoid them altogether? Our Sensitive Dishwashing Liquid contains no added SLES* or SLS. Questions about any of our ingredients? Our customer service team is happy to help at enq@naturesorganics.com.au.
*Sodium Coco Sulfate is a mix of chain lengths and has some SLS.