active
Water
The universal aqueous vehicle for cosmetic formulations. Functions as solvent, carrier, and primary vehicle for all water-phase ingredients.
Benefits
- Universal solvent for hydrophilic actives
- Primary vehicle in aqueous formulations
- Provides skin hydration on contact
- Required for emulsification of oil-in-water products
- Vehicle for electrolyte and pH buffer systems
Example uses
- All aqueous cosmetic formulations
- Cleansers
- Emulsions
- Toners
- Serums
Mechanism of action
Functions as solvent by providing aqueous phase for dissolution of hydrophilic actives, electrolytes, and humectants. Transient hydration on skin contact via surface water film that reduces TEWL temporarily before evaporating.
Clinical evidence · High
Complete safety characterisation. Role as vehicle definitively established.
Effective concentration range
q.s. (primary vehicle)
Formulation notes
Must be purified (deionised/distilled) for cosmetic use to avoid mineral contamination affecting stability and actives. pH control required. The foundation of all aqueous formulation systems.
Watchouts
Not a skin active — provides transient surface hydration only on evaporation. Quality control of water purity critical for preservation and stability.
Market positioning
Sold as primary vehicle and hydration provider. Accurate for vehicle function. Active skin benefit from water alone is transient.
Comedogenicity
0 / 5
Sensitisation risk
Low
INCI & aliases
Aqua
aqua · eau · purified water · deionized water
Clean beauty perception
Universally accepted. The most ubiquitous cosmetic ingredient. No safety controversy.
Graph relationships
Timeline