What Is Quaternium-90 Montmorillonite?
Quaternium-90 Montmorillonite is a hybrid ingredient created by combining Quaternium-90, a positively charged conditioning agent, with montmorillonite, a naturally occurring clay mineral mined from volcanic ash deposits. When these two materials react, the clay’s plate-like particles become coated with the quaternary compound, giving the mineral a new surface chemistry that disperses evenly in water and oil mixtures.
This technology emerged in the late 1990s when formulators sought alternatives to traditional surfactants that could both stabilize emulsions and add a silky after-feel. Manufacturers typically start by purifying raw montmorillonite clay, then treating it with a Quaternium-90 solution under controlled temperature and pH. The mixture is filtered, dried and milled into a fine powder ready for cosmetic use.
You will most often find Quaternium-90 Montmorillonite in creamy masks, rinse-off conditioners, leave-in styling products, makeup primers, sunscreens and rich body butters where smooth texture and even pigment or oil dispersion are required.
Quaternium-90 Montmorillonite’s Cosmetic Benefits/Uses
In formulas this ingredient delivers two main technical benefits that translate into a better user experience.
- Emulsifying: Its dual water-loving and oil-loving surfaces help bind oil and water phases so lotions stay uniform, colors do not separate and active ingredients spread consistently across the skin or hair
- Viscosity controlling: The clay plates swell slightly and create a network that thickens the formula, giving creams a luxurious cushiony texture while preventing runny or watery consistency
Who Can Use Quaternium-90 Montmorillonite
This clay-based emulsifier is gentle enough for most skin types. Oily skin benefits from its light oil-absorbing feel while dry and sensitive skin appreciate the creamy texture it helps create without leaving a tight or chalky finish. It is generally non-comedogenic so it suits combination and blemish-prone complexions as well. People with extremely reactive or allergy-prone skin should check the full ingredient list of a product to be sure no other triggers are present.
Because both the clay and the quaternary compound are made from mineral and synthetic sources, Quaternium-90 Montmorillonite is suitable for vegans and vegetarians. No animal-derived raw materials are used during its manufacture.
Current safety data show no specific risks for pregnant or breastfeeding women when this ingredient is used topically in rinse-off or leave-on products. Still, this is not medical advice and anyone who is expecting or nursing should review any skincare routine with a qualified healthcare provider.
The ingredient does not make skin more sensitive to sunlight and can be worn day or night without increasing the chance of sunburn. It also works well alongside common actives such as vitamin C, niacinamide and retinoids without breaking them down.
Potential Side Effects/Adverse Reactions
Responses to topical Quaternium-90 Montmorillonite vary from person to person. The effects listed below are possible yet uncommon when the ingredient is used at the levels normally found in cosmetic products.
- Mild skin redness or itching in individuals allergic to quaternary compounds
- Temporary dryness if used in very high concentrations on already dehydrated skin
- Eye irritation if the product accidentally gets into the eyes
- Heavy or coated feel on very fine hair when over-applied in styling products
- Reduced absorption of leave-on actives if layered immediately on top of a thick clay-rich product
If any discomfort, irritation or other unwanted effect occurs, discontinue use and consult a healthcare professional or dermatologist for guidance.
Comedogenic Rating
Rating: 1/5
Quaternium-90 Montmorillonite is mostly made of a clay mineral that naturally absorbs excess oil without blocking pores. The quaternary coating helps the clay mix into creams but does not leave a heavy residue. Because it rinses off or sits on the skin surface rather than seeping deep into follicles, the chance of clogged pores is very low. The minimal rating of 1 reflects that slim possibility for congestion in very sensitive or over-layered routines.
Suitable for acne-prone or breakout-prone skin in most cases.
As with any thickening agent, piling on multiple products that all contain this ingredient could build up film on the skin or hair, so keep an eye on overall layer count to avoid dullness or residue.
Summary
Quaternium-90 Montmorillonite acts as a two-in-one helper: it pulls oil and water together so lotions stay smooth and stable, and it thickens formulas to give creams, masks and conditioners a plush texture that spreads evenly. The clay plates provide the body while the quaternary coating brings the emulsifying power.
It is a niche but growing ingredient. You will spot it more in modern masks, sunscreens and styling creams where brands want a silky feel without relying on heavier waxes.
Current research and global safety reviews show it is low risk for skin and the environment. Still, everyone’s skin is different so patch test any new product that lists Quaternium-90 Montmorillonite near the top of the label to make sure it plays nicely with your routine.