Quaternium-91
What is Quaternium-91?
Quaternium-91 is a synthetic cationic copolymer made from quaternary ammonium salts, acrylamide, and acrylic acid monomers. Primarily found in rinse-off hair care products like conditioners and leave-in treatments, it serves as an antistatic and conditioning agent. Its positively charged quaternary ammonium groups attract and bind to the negatively charged hair shaft, creating a thin lubricating film. This mechanism smooths the hair cuticle, decreases inter-fiber friction, neutralizes static buildup, and facilitates easier detangling. The polymer's film-forming properties also enhance shine and softness without heavy residue, making it ideal for everyday hair maintenance in shampoos, conditioners, and styling aids.
Roles in Formulation
This ingredient serves the following purposes in cosmetic formulations:
Benefits
Boosts hair smoothness and softness by coating the shaft.
Minimizes static electricity and frizz for easier styling.
Aids detangling and improves overall hair manageability.
Who It's For
A quick guide for who this ingredient may suit (and who should be cautious).
| Who May Benefit | Who Should Avoid |
|---|---|
| People with dry, brittle, or chemically treated hair. | Users allergic to quaternary ammonium compounds. |
| Individuals dealing with frizzy or static-prone hair. | People with highly reactive or damaged scalps. |
| Those wanting lightweight conditioning in daily routines. | Those avoiding synthetic polymers in hair products. |
Safety Notes
- Rated low hazard (EWG score 1) with minimal concerns.
- Deemed safe for cosmetic use by ingredient review experts.
Frequently Asked Questions about Quaternium-91
What does Quaternium-91 do in hair products?
It acts as a conditioning agent, smoothing hair and reducing static for better manageability.
Is Quaternium-91 irritating?
Evidence indicates low irritation risk in typical cosmetic concentrations.
Can it worsen acne?
It carries a comedogenic rating of 0, suitable for pore-friendly routines.