Ingredient review
Quaternium-90 Bentonite
INCI: Quaternium-90 Bentonite
A gentle clay derivative that improves product feel and stability, but offers no direct skin benefit.
In plain English
Quaternium-90 Bentonite is a clay mineral that has been chemically modified to make it more compatible with water and oils in skincare formulas. It helps thicken products, gives them a smooth, creamy texture, and can help suspend other ingredients. It does not actively treat skin conditions but is considered safe and non-irritating for most people.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Quaternium-90 Bentonite is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Quaternium-90 Bentonite.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A semi-synthetic ingredient made by treating natural bentonite clay with a quaternary ammonium compound (a type of positively charged molecule). This modification allows the clay to mix well with both water and oil, making it useful in a wide range of cosmetic formulations.
How it works
It acts as a rheology modifier, meaning it changes how a product flows and feels. It thickens the formula, prevents ingredients from separating, and gives a silky, spreadable texture. It can also help stabilize emulsions (mixtures of oil and water) and improve the application of creams and lotions.
Pros
Gentle and low-irritation
Quaternium-90 Bentonite has a low irritation risk and is generally well-tolerated, even by sensitive skin types, making it a safe choice for daily use products.
Improves product feel
It gives creams and lotions a smooth, silky texture that spreads easily, enhancing the user experience without adding greasiness.
Cons and cautions
No active skin benefit
This ingredient is purely functional — it improves product texture and stability but does not hydrate, exfoliate, or treat any skin concerns.
Potential heaviness for oily skin
In high concentrations, it may feel slightly heavy or mask-like on very oily skin, though this is uncommon in typical formulations.
Best for
- Anyone looking for a stable, well-textured cream or lotion
- People with sensitive skin who tolerate clay-based products well
Use caution if
- Those who prefer minimal-ingredient, clay-free formulations
Usage tips
Safety summary
Quaternium-90 Bentonite is considered safe for use in cosmetics. It has low irritation and comedogenic potential, and no significant safety concerns have been reported in standard use concentrations.
Research notes
Research on quaternized clays focuses on their functional properties as thickeners and stabilizers. Safety assessments by cosmetic review panels confirm low risk, but there are no studies showing direct skin benefits beyond formulation support.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. The Cosmetic Ingredient Review (CIR) panel has evaluated quaternized clays and found them safe at typical use concentrations.
- Common uses
- Creams, Lotions, Masks, Makeup
- Environmental note
- Bentonite is a naturally abundant clay mineral, but the quaternization process involves synthetic chemicals. Environmental impact is considered low due to small usage amounts.
Good to know
- Quaternium-90 Bentonite is often used in combination with other thickeners to achieve the perfect consistency.
- It is considered a 'clean' ingredient by many standards, as it is derived from natural clay and modified with safe compounds.
Common questions
What is Quaternium-90 Bentonite in beauty products?
Quaternium-90 Bentonite is a clay mineral that has been chemically modified to make it more compatible with water and oils in skincare formulas. It helps thicken products, gives them a smooth, creamy texture, and can help suspend other ingredients. It does not actively treat skin conditions but is considered safe and non-irritating for most people.
What does Quaternium-90 Bentonite do in a beauty product?
It acts as a rheology modifier, meaning it changes how a product flows and feels. It thickens the formula, prevents ingredients from separating, and gives a silky, spreadable texture. It can also help stabilize emulsions (mixtures of oil and water) and improve the application of creams and lotions.
Is Quaternium-90 Bentonite safe for most people?
Quaternium-90 Bentonite is considered safe for use in cosmetics. It has low irritation and comedogenic potential, and no significant safety concerns have been reported in standard use concentrations.
Who should be careful with Quaternium-90 Bentonite?
Those who prefer minimal-ingredient, clay-free formulations
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.