Hydrogenated Styrene/Isoprene Copolymer is a synthetic hydrogenated block copolymer used in cosmetics primarily as a viscosity-controlling agent, emollient, and film former, helping stabilize formulations and improve texture and wear (e.g., in lip products and color cosmetics). It is considered chemically stable and generally well tolerated.
| Reported effect | How often | Notes |
|---|---|---|
Skin irritation | Rare | Mild irritation is uncommon; the polymer is generally considered low-irritant in standard cosmetic concentrations. |
Allergic contact dermatitis | Very rare | Sensitization is rarely reported; reactions are more often attributed to other formulation components. |
Acneiform breakout/occlusion | Rare | As an occlusive film former it could theoretically contribute to clogged pores in predisposed individuals, but data are limited. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.