Polyquaternium-67 is a sophisticated cationic conditioning polymer that provides superior film-forming properties and substantivity without the typical buildup associated with traditional silicons. This hydrophobically modified cellulose derivative excels at enhancing the deposition of active ingredients and providing a smooth, “clean-feel” finish to both skin and hair.
- INCI Name:
- Polyquaternium-67
- Chemical/Scientific Name:
- 2-hydroxyethyl ether cellulose, polymer with N,N,N-trimethyl-3-(2-propen-1-yloxy)-1-propanaminium chloride and N,N-dimethyl-N-octadecyl-3-(2-propen-1-yloxy)-1-propanaminium chloride
- Common Aliases:
- Quaternized hydroxyethylcellulose, SoftCAT Polymer
| Category: | Texture Enhancers |
| Source Origin: | Synthetic derivative of natural Cellulose |
| Comedogenic Rating: | 0 |
| Primary Industries: | Hair care, personal wash, high-end skin care |
| Solubility: | Water-soluble |
At a Glance: Properties & Effects
| Texture Enhancement: | |
| Barrier Repair: | |
| Soothing/Calming: | |
| Irritation Risk: |
- Primary Benefits:
- Delivers extreme silkiness and slip without greasy residue.
- Improves the deposition of lipids and beneficial oils onto the skin and hair.
- Maintains formula clarity while providing high-viscosity conditioning.
- Reduces static and frizz in hair care applications.
- Potential Risks:
- Minimal risk of accumulation if used in excessively high concentrations in leave-on products.
- Potential for incompatibility with specific high-load anionic surfactant systems if not formulated correctly.
Biological Action & Cosmetic Profile
Cationic polymers like Polyquaternium-67 function primarily through electrostatic attraction. Because skin and hair surfaces typically carry a negative charge—particularly when damaged—the positively charged (cationic) nitrogen groups on the polymer backbone bind effectively to these surfaces. This ingredient is a next-generation version of Polyquaternium 10, featuring hydrophobic modification. This specific molecular change allows the polymer to not only bind to the surface but also to anchor other beneficial ingredients, such as botanical oils or Dimethicone, more effectively during the rinsing process.
The molecular structure is based on a Hydroxyethylcellulose backbone. While standard conditioners can sometimes leave a heavy, weighed-down feeling, the hydrophobic modification in Polyquaternium-67 ensures a more discreet, breathable film. In surfactant-based systems like body washes, it facilitates the “coacervation” process. This is a phase separation where the polymer and surfactants form a complex that “bursts” upon dilution with Aqua, depositing a conditioning layer that remains after the suds are washed away.
Clinical observations suggest that this polymer improves the skin’s tactile properties immediately upon application. It provides a significant reduction in friction, which can indirectly aid in preventing mechanical irritation to the skin barrier. While it does not penetrate the stratum corneum, its ability to retain Glycerin and other humectants near the surface enhances the overall hydration profile of the finished cosmetic product.
Broader Applications & Origins
Commercial production of Polyquaternium-67 involves the chemical modification of wood pulp or cotton linter cellulose. By reacting the cellulose with various etherifying agents and quaternary ammonium compounds, chemists create a material that bridges the gap between natural thickeners and high-performance synthetic conditioners. Its primary utility spans across premium shampoos, moisturizing body washes, and facial cleansers where a luxurious after-feel is required without the use of heavy waxes.
Routine Integration
- Synergies:
- Surfactants: Enhances foam creaminess and stability in sulfate-free systems.
- Lipids: Works exceptionally well with Butyrospermum Parkii Butter by improving its deposition from rinse-off formulas.
- Humectants: Helps lock in the effects of Panthenol on the hair shaft.
- Conflicts:
- Highly Anionic Gellants: High concentrations of Carbomer may occasionally require careful neutralization to prevent the formation of visible complexes or “strings” in the texture.
Clinical Consensus & Safety
The Cosmetic Ingredient Review (CIR) Expert Panel has evaluated the Polyquaternium family of ingredients and generally considers them safe for use in cosmetic formulations. Studies on Polyquaternium-67 specifically highlight its low potential for dermal sensitization and ocular irritation, making it suitable for “tear-free” formulations and products intended for sensitive skin. Because it is a large polymer with a high molecular weight, it is not absorbed through the skin, further minimizing systemic safety concerns. Current industry standards allow for its use in concentrations ranging from 0.1% to 1.0% in most leave-on and rinse-off applications.
Is Polyquaternium-67 a silicone?
No, Polyquaternium-67 is a modified cellulose polymer. While it provides many of the smoothing and conditioning benefits associated with silicones, it is chemically distinct and water-soluble, making it a popular choice for silicone-free claims.
Will this ingredient cause “buildup” on my hair or skin?
Polyquaternium-67 is engineered to have a lower buildup potential than older cationic polymers like Guar Hydroxypropyltrimonium Chloride. Its hydrophobic modifications allow it to rinse away more cleanly while still leaving a fine, protective layer where it is most needed.
Is it vegan and biodegradable?
The starting material is cellulose, which is plant-derived. However, the subsequent chemical modifications involve synthetic quaternizing agents. While the cellulose backbone is biodegradable, the modified polymer’s rate of biodegradation is slower than pure cellulose, though it is generally considered acceptable for modern environmental standards in personal care.