The Health and Environmental Risks of SLS and SLES
by Kay Baker on Feb 28, 2024
The Hidden Chemical in Your Soap (And Why 2025 Changes Everything)
🎯 What You Need to Know in 30 Seconds
- The issue: Many popular cleaners contain a hidden contaminant called 1,4-dioxane—a likely carcinogen that won't show up on labels
- The good news: New rules in 2025 are finally forcing companies to clean up their act
- Your power move: Choose sulfate-free cleaners or brands that test for ultra-low levels (and actually tell you about it!)
Wait—there's a what in my cleaner?
Here's something wild: You could read every single ingredient on your soap bottle and still have no idea about one of the most concerning chemicals hiding inside.
Meet 1,4-dioxane—a chemical you've probably never heard of, but might be using every day. It's not added on purpose. Companies don't list it on labels. Yet the EPA now considers it an "unreasonable risk" to your health.
So how did we get here? And more importantly—what changed in 2024 that's making 2025 the year of cleaner cleaners? Let's break it down in plain English.
The foam that comes with a side effect
You know that satisfying lather you get from shampoo, body wash, or dish soap? Much of that comes from ingredients called SLS (Sodium Lauryl Sulfate) and its gentler cousin, SLES (Sodium Laureth Sulfate).
Here's where it gets interesting: When companies make SLES, they put SLS through a process called "ethoxylation" to make it milder on your skin. Sounds great, right?
The catch? That process can accidentally create 1,4-dioxane as a byproduct. Think of it like burning toast—you didn't want the burnt parts, but they showed up anyway during cooking.
Why this matters to you: The U.S. EPA lists 1,4-dioxane as a likely human carcinogen. Studies link it to cancer risk, liver issues, and respiratory problems. And because it's a "contaminant" rather than an "ingredient," companies don't have to tell you it's there.
What changed in 2024 (the breakthrough moment)
For years, this issue flew under the radar. But in November 2024, something major happened:
The EPA officially declared 1,4-dioxane presents an "unreasonable risk" to human health.
Translation? The science is clear enough that the government can no longer ignore it. This opens the door for:
- Stricter manufacturing rules
- Better worker protections
- Tougher water quality standards
- More pressure on brands to reformulate
Think of 2024 as the tipping point—and 2025 as the year we'll see real change.
The states leading the charge
While federal rules take time, some states aren't waiting around:
🗽 New York
Was the first to set strict limits back in 2022. By the end of 2025, products must contain:
- ≤1 ppm (parts per million) for personal care and household cleaners
- ≤10 ppm for cosmetics
Companies that couldn't meet these standards? They had to either reformulate or stop selling in New York.
🌉 California
Taking it even further with a two-punch approach:
- Water standards: Alert level dropped to 1 microgram per liter (that's incredibly low)
- Cosmetics ban: As of January 2025, no 1,4-dioxane allowed as a contaminant—period
Why state rules matter nationally: When the two biggest consumer markets in the U.S. set strict standards, most brands just reformulate for everyone rather than making different versions. Your gain, even if you don't live in NY or CA!
How to shop smarter (your action plan)
You don't need a chemistry degree to make safer choices. Here's what to look for:
✅ The "Avoid" List
Watch out for products with these ingredients (they're often made through ethoxylation):
- Sodium Laureth Sulfate (SLES)
- Anything ending in "-eth" (like Ceteareth, Steareth, Oleth)
- PEG compounds (Polyethylene Glycol)
- Polysorbates
✨ The "Choose This Instead" List
These gentler alternatives don't involve ethoxylation, so no 1,4-dioxane risk:
- Cocamidopropyl Betaine (CAPB): Gentle foam booster from coconut
- Decyl Glucoside: Super mild, plant-derived, great for sensitive skin
- Sodium Cocoyl Isethionate (SCI): Sulfate-free powerhouse (hello, better bar soaps!)
- Cocoyl Glutamate: Amino acid-based, ridiculously gentle
- Soap Nut Extracts: Natural saponins for light cleaning jobs
Real talk: These alternatives actually work better for many people with sensitive skin. Less irritation, same clean. Win-win!
What about brands that still use SLES?
Not all SLES is created equal anymore. The good news? Technology has improved dramatically:
- Ultra-low grades now exist: Some suppliers offer SLES with ≤5 ppm of 1,4-dioxane (that's 70% active concentration)
- Vacuum stripping works: After ethoxylation, manufacturers can remove most of the contaminant under vacuum
- Smart formulating helps: Keep SLES at ≤14% of the total formula to stay under the 1 ppm finished product limit
The catch? Companies have to actually do this—and test to prove it. That costs more money, which is why cheaper products often skip these steps.
If you have well water or groundwater concerns
1,4-dioxane doesn't just stay in products—it can contaminate water supplies near manufacturing sites or wastewater treatment plants.
What works to remove it:
- UV Advanced Oxidation: Proven effective at large utility scale
- Ozone treatment: Works when properly tuned
- Standard carbon filters? Not so much. They break through quickly with 1,4-dioxane
If you're concerned about your water, check your local water quality report or contact your utility. California's new 1 μg/L notification level means more testing and public disclosure.
What happens next in 2025
Mark your calendar for these milestones:
- Right now: California's cosmetics ban is in effect
- December 2025: New York's grace period ends—full enforcement begins
- Late 2025: EPA expected to propose official risk management rules under TSCA
- Ongoing: More states likely to adopt similar standards (watch Maryland, Washington, Illinois)
What this means for you: More brands will quietly reformulate to meet the strictest state standards. Your store shelves will get safer without you doing anything—but knowing what to look for helps you choose the leaders, not the laggards.
Ready to skip the worry?
Our sulfate-free, plant-powered cleaners were designed from day one to avoid questionable chemicals—including those hiding between the lines.
Shop Clean FormulasYour questions answered
- Are SLS and SLES the same thing?
- Nope! SLS (Sodium Lauryl Sulfate) is the original sulfate cleanser. SLES (Sodium Laureth Sulfate) is SLS that's been ethoxylated to make it gentler—but that ethoxylation process is where 1,4-dioxane can sneak in.
- Why don't I see 1,4-dioxane listed on ingredient labels?
- Because it's technically a manufacturing byproduct or "contaminant," not an intentional ingredient. Companies aren't required to list it—which is exactly why consumer advocates have been pushing for change.
- How low should 1,4-dioxane levels actually be?
- New York set the bar at ≤1 ppm for cleaners and personal care, ≤10 ppm for cosmetics. California just said "none as a contaminant" in cosmetics. The safest bet? Choose products that avoid ethoxylation altogether.
- Can formulators keep SLES but still meet the new standards?
- Yes, with ultra-clean SLES inputs, careful formulation (keeping SLES content modest), and third-party testing to verify each batch. Or they can switch to the sulfate-free alternatives listed above and skip the drama entirely.
- Should I be worried about 1,4-dioxane in my drinking water?
- If you're on municipal water, check your annual water quality report—utilities test for it. If you have well water near industrial areas, consider getting it tested. Where contamination exists, UV treatment systems work best.
- Is Green Llama completely sulfate-free?
- We focus on compact refills and gentle, non-ethoxylated cleaning systems. Check individual product pages for full ingredient lists—we publish everything, including CAS numbers, because transparency matters.
Want to dig deeper?
If you're the type who likes to verify (we love that!), here are trusted resources:
- Campaign for Safe Cosmetics — Consumer advocacy and ingredient info
- Chemical & Engineering News — How companies are removing 1,4-dioxane
- US EPA — Official risk determinations and regulatory updates
- David Suzuki Foundation — The Dirty Dozen ingredients to avoid
The bottom line
Look, we get it—ingredient labels are confusing enough without having to worry about chemicals that aren't even listed. That's exactly why we started Green Llama: to make safer cleaning so simple you don't need a chemistry degree.
The good news? Change is happening. States are stepping up. Companies are reformulating. And you now know how to spot the difference between brands that are ahead of the curve and those just doing the minimum.
Your move is simple: Choose sulfate-free when you can, demand transparency always, and know that every conscious choice you make creates ripples that push the whole industry forward.
Together, we're making "clean" actually mean clean—no hidden asterisks required. 🌱
