Back to Ingredient Dictionary
Common Name(s): Hydroxypropyl chitosan,water-soluble cationic biopolymer,neutral ph hair skin conditioner
CAS Number: N/a
DESCRIPTION
What It Does: Deposits cationic conditioning film on hair and skin at neutral ph (unlike native chitosan requiring ph below 5), provides antimicrobial activity from chitosan membrane disruption, and delivers humectant moisture retention from hydroxypropyl polyol groups.
Why It's Used: Hydroxypropyl modification solves chitosan's most important formulation limitation โ cold-water insolubility requiring acidic ph โ enabling neutral-ph cosmetic formulation alongside ph-sensitive actives while retaining all conditioning benefits.
How It Works: Hydroxypropyl substitution (ds 0.5-1.5) introduces bulky -och2ch(oh)ch3 groups at c6/c2 positions sterically disrupting inter-chain h-bonding crystallinity. the steric bulk restores water solubility at ph 5-7 while the amine groups (pka 6.5) remain protonatable providing cationic character for electrostatic adsorption on hair cuticle and skin corneocytes.
Typically Found In: Hair conditioners,skin care,natural conditioning
TECHNICAL DETAILS
Primary Category: Active ingredient โ cosmetic active
Secondary Functions: Skin conditioning
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.1%โ3%
SOURCING & ETHICS
Vegan Status: Conditional - crustacean or fungal route; fungal chitosan is vegan
Halal Status: Conditional - crustacean or fungal route; feedstock declaration required
Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: chitin family; a fungal route exists that is both halal-simpler and vegan, so origin must be declared. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Well-tolerated by most skin types.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile at recommended concentrations. ewg score: 1โ2.
Works Well With: Standard skincare actives
Avoid Combining With: No known significant incompatibilities
SCIENTIFIC NOTE
Fungal chitosan from aspergillus niger or rhizopus sp. provides a vegan alternative โ identical chemistry to crustacean chitosan, cosmos-potentially acceptable from food-grade fungal sources, free from shellfish allergen concerns.
Last Verified: 2026-03-12
Primary Sources: Cosing database,hydroxypropyl chitosan water-soluble cationic review