Polymethyl-silsesquioxane ●
TL;DR. This ingredient is a synthetic texture powder and film-forming agent that gives formulas slip, a soft-focus finish, and oil-control or mattifying effects. It is common in primers, foundations, powders, sunscreens, and long-wear color cosmetics.
What does Polymethyl-silsesquioxane do in a cosmetic formula?
This ingredient is a synthetic texture powder and film-forming agent that gives formulas slip, a soft-focus finish, and oil-control or mattifying effects. It is common in primers, foundations, powders, sunscreens, and long-wear color cosmetics.
Is Polymethyl-silsesquioxane clean?
From a clean-beauty perspective, it is usually flagged because it is a persistent synthetic polymer used for sensory performance rather than skin benefit. Skin irritation potential is generally low because the particles are large and inert, but many stricter standards limit this material class.
Is Polymethyl-silsesquioxane sustainable?
This material is made through mineral and petrochemical-derived chemistry and is not readily biodegradable. Its main sustainability concern is environmental persistence after rinse-off or wear-off, rather than acute skin reactivity.
Is Polymethyl-silsesquioxane COSMOS-approved?
It is not permitted under COSMOS natural or organic standards for typical cosmetic use. Its low reactivity is useful in formulation, but its synthetic origin and poor biodegradability make it a weak fit with Green Chemistry priorities.
How does Polymethyl-silsesquioxane work chemically?
The molecule is a crosslinked network built from methyl-substituted silicon-oxygen units, forming spherical or irregular particles that are insoluble in water and oils. Typical use levels are often around 1% to 10% for slip, blurring, and mattifying effects, and it is broadly stable across normal cosmetic pH and heat-processing conditions.
Last updated 2026-05-15