Propylene Glycol — Allergy Risk & Safety Profile
INCI: PROPYLENE GLYCOL
Also known as: PG, 1,2-Propanediol, Methylethylene Glycol
Key Facts
- CAS Number
- 57-55-6
- Category
- humectant
- Risk Level
- medium
- Common Allergen
- Yes
- Found In
- moisturizer, serum, deodorant, toothpaste
Is Propylene Glycol safe in cosmetics?
Propylene Glycol is rated medium risk in cosmetic products. It is a known allergen that can cause contact dermatitis in sensitized individuals. Named ACDS Allergen of the Year in 2018. Irritant at high concentrations, true allergen for some. Safer alternatives include Glycerin, Hyaluronic Acid, Aloe Vera. Commonly found in moisturizer, serum, deodorant.
What is Propylene Glycol?
Very common humectant and solvent. Generally safe but can cause irritation in sensitive individuals.
Allergy & Safety Information
Propylene Glycol 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 Humectant Ingredients
Humectants attract water molecules from the environment and from deeper skin layers, drawing moisture into the stratum corneum. They are among the safest cosmetic ingredients — molecules like glycerin, hyaluronic acid, and panthenol have extremely low sensitisation rates and are well-tolerated by almost all skin types.
Relevance for Propylene Glycol: In very low humidity environments, humectants can draw moisture out of the skin rather than into it. This is particularly relevant for high-molecular-weight hyaluronic acid applied to dry skin without an occlusive layer to seal moisture in.
How to Identify Propylene Glycol 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 Propylene Glycol, 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: Moisturizer, Serum, Deodorant, Toothpaste. These product categories are the most common sources of Propylene Glycol exposure based on formulation data.
Not sure if your products contain Propylene Glycol? Paste the ingredient list into the free ingredient checker to scan for Propylene Glycol and other allergens automatically.
Safer Alternatives
These ingredients serve a similar function with lower allergy risk:
Frequently Asked Questions
Is Propylene Glycol safe for sensitive skin?
Propylene Glycol may cause reactions in some sensitive individuals. Patch testing is advisable.
What products contain Propylene Glycol?
Propylene Glycol is commonly found in moisturizer, serum, deodorant, toothpaste.
What does Propylene Glycol do in cosmetics?
Propylene Glycol functions as a humectant in formulations. Named ACDS Allergen of the Year in 2018. Irritant at high concentrations, true allergen for some.
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Is Propylene Glycol causing YOUR skin reactions?
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