Science
Mechanism of Action
This ingredient primarily acts as a water-in-silicone (W/Si) emulsifier and surfactant. It works by forming a stable interface between immiscible water and silicone components, thereby enabling the integration of diverse active ingredients. On the skin, it contributes to a non-occlusive film, which improves the product's spreading characteristics, wash-off resistance, and wear duration, while also aiding in the uniform dispersion of pigments.
Research
Clinical Evidence
High confidenceN/A
Key findings
- 01 Dimethicone Copolyol (a broader category including PEG/PPG-19/19 Dimethicone) was found to be nonirritating and nonsensitizing on 201 volunteers.
- 02 PEG/PPG-19/19 Dimethicone at a 5% concentration in water was not a sensitizer in guinea pigs.
- 03 Dimethicone Copolyol in aqueous solution (40%) and undiluted (100%) was not a primary skin irritant on 39 subjects.
Transparency
Dusting Analysis
No data regarding 'dusting' properties or associated thresholds for PEG/PPG-19/19 Dimethicone were found in the research.
The Formula
Formulation
Stability
This ingredient offers optimal performance within a slightly acidic to moderate pH range and demonstrates tolerance to moderate levels of inorganic electrolytes. It is typically employed by first dissolving it in a volatile siloxane. Stable emulsion formation critically depends on the precise emulsifier level; insufficient amounts can lead to sedimentation, while excessive amounts may result in an overly viscous or broken emulsion. Stability can be significantly enhanced through high shear mixing post-emulsification. It excels at stabilizing high concentrations of glycols (such as glycerin) and aluminum salts within the water phase.
Synergies
- Glycols (e.g., glycerin)
- Aluminum salts
Safety
Safety Profile
The Cosmetic Ingredient Review (CIR) Expert Panel concluded that Dimethicone Copolyols, including PEG/PPG-19/19 Dimethicone, are safe for use in cosmetics. Studies indicate at most slight oral toxicity (100% concentration, LD50 > 16 mL/kg in rats) and practical nontoxicity via dermal application in rats and rabbits, with no primary skin or ocular irritation. While the EWG notes potential concerns regarding trace impurities like Cyclopentasiloxane, Cyclotetrasiloxane, Ethylene Oxide, and 1,4-Dioxane that may necessitate restrictions for EWG VERIFIED products, the CIR's safety assessment for the ingredient itself remains positive.
Your Skin
Skin Compatibility
Our Assessment
Verdict
PEG/PPG-19/19 Dimethicone is a valuable and well-tolerated emulsifier, enabling the creation of advanced water-in-silicone formulations with enhanced aesthetic properties and stability across a broad range of skincare and cosmetic applications.
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References
Sources