Sodium Lauryl Sulfate — Allergy Risk & Safety Profile
INCI: SODIUM LAURYL SULFATE
Also known as: SLS, Sodium Dodecyl Sulfate
Key Facts
- CAS Number
- 151-21-3
- Category
- surfactant
- Risk Level
- medium
- Common Allergen
- Yes
- Found In
- shampoo, toothpaste, body wash, facial cleanser
Is Sodium Lauryl Sulfate safe in cosmetics?
Sodium Lauryl Sulfate is rated medium risk in cosmetic products. It is a known allergen that can cause contact dermatitis in sensitized individuals. Primary irritant, not a true allergen. Disrupts skin barrier allowing other allergens to penetrate. Safer alternatives include Decyl Glucoside, Coco Glucoside, Sodium Cocoyl Isethionate. Commonly found in shampoo, toothpaste, body wash.
What is Sodium Lauryl Sulfate?
Strong surfactant. Not a true allergen but a potent irritant that damages the skin barrier.
Allergy & Safety Information
Sodium Lauryl Sulfate is generally safe for most people but may cause irritation or allergic reactions in sensitive individuals. If you experience redness, itching, or swelling after using a product with this ingredient, discontinue use and consult a dermatologist.
This ingredient carries moderate allergenicity risk. It can cause reactions in sensitised individuals but has a lower sensitisation rate than high-risk ingredients. Patch testing before full use is advisable for anyone with a history of cosmetic reactions.
About Surfactant / Cleansing Agent Ingredients
Surfactants reduce surface tension between water and oil, allowing products to cleanse, foam, and emulsify. They are essential in shampoos, cleansers, and body washes. However, surfactants vary widely in irritation potential — from harsh (sodium lauryl sulfate) to very mild (sodium lauroyl sarcosinate, decyl glucoside).
Relevance for Sodium Lauryl Sulfate: Repeated daily use of strong surfactants disrupts the skin barrier by removing natural lipids, increasing sensitivity to other allergens over time. If you have reactive or eczema-prone skin, choosing low-irritation surfactants and limiting wash time reduces barrier damage.
How to Identify Sodium Lauryl Sulfate in Products
Cosmetic ingredients are listed by their INCI (International Nomenclature of Cosmetic Ingredients) name in descending order of concentration. To check whether a product contains Sodium Lauryl Sulfate, scan the ingredient list for its INCI name exactly as it appears above. Ingredients present at 1% or less may appear in any order after the 1% threshold.
Product types to prioritise checking: Shampoo, Toothpaste, Body wash, Facial cleanser. These product categories are the most common sources of Sodium Lauryl Sulfate exposure based on formulation data.
Not sure if your products contain Sodium Lauryl Sulfate? Paste the ingredient list into the free ingredient checker to scan for Sodium Lauryl Sulfate and other allergens automatically.
Cross-Reactions
If you react to Sodium Lauryl Sulfate, you may also react to:
Safer Alternatives
These ingredients serve a similar function with lower allergy risk:
Frequently Asked Questions
Is Sodium Lauryl Sulfate safe for sensitive skin?
Sodium Lauryl Sulfate may cause reactions in some sensitive individuals. Patch testing is advisable.
What products contain Sodium Lauryl Sulfate?
Sodium Lauryl Sulfate is commonly found in shampoo, toothpaste, body wash, facial cleanser.
What does Sodium Lauryl Sulfate do in cosmetics?
Sodium Lauryl Sulfate functions as a surfactant in formulations. Primary irritant, not a true allergen. Disrupts skin barrier allowing other allergens to penetrate.
Related Guides
Top 10 Cosmetic Allergens
Is Sodium Lauryl Sulfate on the list? See the full clinical ranking.
Sulfates in Skincare & Shampoo
Which surfactants damage the barrier and safer alternatives.
How to Read Ingredient Labels
Decode INCI names and find hidden allergens in your products.
Find Your Skin Allergy Trigger
Step-by-step elimination method to identify your trigger.
Contact Dermatitis Guide
Symptoms, causes, patch testing, and treatment options.
Is Sodium Lauryl Sulfate causing YOUR skin reactions?
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