Potassium Alum — Allergy Risk & Safety Profile
INCI: POTASSIUM ALUM
Key Facts
- CAS Number
- 7784-24-9
- Category
- active
- Risk Level
- low
- Common Allergen
- No
- Found In
- crystal deodorant, aftershave
Is Potassium Alum safe in cosmetics?
Potassium Alum is rated low risk in cosmetic products. It is not classified as a common allergen and is generally well-tolerated by most skin types. Commonly found in crystal deodorant, aftershave.
What is Potassium Alum?
Potassium Alum is a active commonly used in cosmetic and personal care products. It is generally considered safe for use in cosmetics at recommended concentrations.
Allergy & Safety Information
Potassium Alum is considered safe for cosmetic use at typical concentrations.
This ingredient is considered low risk from an allergenicity perspective. Reactions are uncommon at typical cosmetic use concentrations. However, no ingredient is universally safe — if you notice redness, itching, or irritation after using a product containing this ingredient, discontinue use and monitor whether symptoms resolve.
About Active Ingredient Ingredients
Active ingredients are formulated to produce a specific skin benefit — exfoliation, brightening, anti-ageing, or acne treatment. They work by interacting directly with skin biology, which also means they carry higher irritation potential than passive ingredients like emollients or thickeners.
Relevance for Potassium Alum: Actives often require an adjustment period during which temporary redness, dryness, or sensitivity is normal. However, persistent reactions after 4–6 weeks of use, or reactions that worsen rather than improve, suggest true intolerance. Introduce only one active at a time to identify the cause of any reaction.
How to Identify Potassium Alum 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 Potassium Alum, 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: Crystal deodorant, Aftershave. These product categories are the most common sources of Potassium Alum exposure based on formulation data.
Not sure if your products contain Potassium Alum? Paste the ingredient list into the free ingredient checker to scan for Potassium Alum and other allergens automatically.
Frequently Asked Questions
Is Potassium Alum safe for sensitive skin?
Potassium Alum is generally well-tolerated, even by sensitive skin.
What products contain Potassium Alum?
Potassium Alum is commonly found in crystal deodorant, aftershave.
What does Potassium Alum do in cosmetics?
Potassium Alum functions as a active in formulations.
Related Guides
Anti-Aging for Sensitive Skin
The safest actives for sensitive skin and how to use them.
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 Potassium Alum causing YOUR skin reactions?
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