What Is Acryloyloxypropyl Silsesquioxane/Trimethylsiloxysilicate/Butyl Acrylate Crosspolymer?
Acryloyloxypropyl Silsesquioxane/Trimethylsiloxysilicate/Butyl Acrylate Crosspolymer is a man-made silicone-acrylate polymer that blends the flexible feel of silicones with the strong hold of acrylates. It starts with a silicate resin created by mixing tetramethoxysilane, trimethylmethoxysilane and acryloyloxy propyltrimethoxysilane in water then letting them link together. Chemists later add butyl acrylate so the resin and the acrylate form a single three-dimensional network. The result is a fine powder or viscous fluid that disperses easily in oils or volatile silicones.
Silicone resins like this began showing up in makeup labs in the early 2000s when brands wanted longer wear without a heavy feel. By adding an acrylate segment to the classic trimethylsiloxysilicate resin, formulators gained better flexibility and adhesion, two traits needed for modern transfer-resistant color products.
You will see this crosspolymer in long-wear foundations, liquid lipsticks, waterproof mascaras, eyeliners, sunscreens, primers, setting sprays and even some solid stick products. It can also be used in skin care masks or protective creams where a thin breathable shield is useful.
Acryloyloxypropyl Silsesquioxane/Trimethylsiloxysilicate/Butyl Acrylate Crosspolymer’s Cosmetic Benefits/Uses
This ingredient pulls double duty in many formulas thanks to the unique mix of silicone and acrylate chemistry.
- Binding – Helps pigments stick together and stay evenly suspended so color applies smoothly and does not separate in the bottle or on the skin
- Film Forming – Creates a flexible invisible film that locks makeup in place resists water and sweat and reduces transfer onto clothes
- Skin Protecting – Forms a light breathable shield that limits direct contact with external irritants and slows moisture loss helping skin feel comfortable throughout the day
Who Can Use Acryloyloxypropyl Silsesquioxane/Trimethylsiloxysilicate/Butyl Acrylate Crosspolymer
This crosspolymer is considered skin friendly for most skin types because it sits on the surface rather than penetrating deeply. Dry and normal skins tend to appreciate its light moisture-sealing film while oily or acne-prone skins usually tolerate it because the resin is breathable and non-greasy. People with very congested or highly reactive skin might find the film slightly occlusive or sensitising so they may prefer lighter alternatives.
The ingredient is fully synthetic and contains no animal derivatives which makes it acceptable for vegans and vegetarians. It is also cruelty free when sourced from suppliers that do not test on animals.
No specific warnings exist for pregnancy or breastfeeding. The polymer is not absorbed in meaningful amounts and is not known to interfere with hormones. This is not medical advice so anyone who is pregnant or nursing should still check with a healthcare professional before adding new products.
The resin does not make skin more sensitive to sunlight and does not require special timing of application. It can even boost the water resistance of sunscreens.
Potential Side Effects/Adverse Reactions
Reactions to topical Acryloyloxypropyl Silsesquioxane/Trimethylsiloxysilicate/Butyl Acrylate Crosspolymer vary from person to person. The points below list possible issues yet most users will not experience them when the ingredient is formulated correctly.
- Mild skin irritation or redness in very sensitive individuals
- Allergic contact dermatitis triggered by the acrylate portion of the polymer
- Temporary clogged pores or small breakouts if the film is layered with heavy oils or not removed thoroughly
- Eye stinging or watering if the product migrates into the eye area before it fully sets
- Sensation of tightness or dryness if used in high concentrations on already dehydrated skin
If any discomfort or unusual reaction occurs stop using the product and consult a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 1 / 5
This crosspolymer sits on top of the skin as a light breathable film and has a large molecular size, which means it is unlikely to seep into pores and cause blockages. It contains no heavy oils or waxes that tend to trigger breakouts. A rating of 1 reflects a very low chance of clogging pores, though not a perfect zero because any film former can trap debris if layered with rich products or not cleansed off properly.
Most acne-prone users should tolerate it well.
Worth noting: final comedogenicity depends on the whole formula. Pairing the polymer with greasy emollients can raise the overall clogging potential.
Summary
Acryloyloxypropyl Silsesquioxane/Trimethylsiloxysilicate/Butyl Acrylate Crosspolymer is a modern hybrid resin that binds pigments, forms a flexible long-lasting film and shields skin from moisture loss and daily grime. It does this by creating a three-dimensional silicone-acrylate network that grips to the surface without feeling heavy.
It has become a staple in long wear makeup, waterproof mascara, liquid lipstick and transfer-resistant foundation, though it is still less common than classic silicones like dimethicone.
Safety data show it is non-sensitising for most people and not absorbed in a meaningful way. Side effects are rare and usually mild. As with any new ingredient a quick patch test is wise before diving into full-face use.