Tris is a primary amino compound that is tert-butylamine in which one hydrogen attached to each methyl group is replaced by a hydroxy group. A compound widely used as a biological buffer substance in the pH range 79; pKa = 8.3 at 20 C; pKa = 7.82 at 37 C. It has a role as a buffer. It is a triol and a primary amino compound. It is a conjugate base of a member of Htris.
Solubility 79.1 mg/mL in ethylene glycol; 26 mg/mL in methanol; 14.6 mg/mL in anhyd ethanol; 22 mg/mL in 95% ethanol; 14 mg/mL in dimethyl formamide; 20 mg/mL in acetone; 0.5 mg/mL in ethyl acetate; 0.4 mg/mL in olive oil; 0.1 mg/mL in cyclohexane; 0.05 mg/mL in chloroform; less than 0.05 mg/mL in carbon tetrachloride
Formula
C4H11NO3
Mol. Weight
121.14
CAS #
77-86-1
Form
Liquid
State
Liquid; Other Solid
See origin →
Functions
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Buffering
Provides scent
Maintains optimal pH
Traditional Use
A synthetic buffering agent developed in the mid-20th century for pharmaceutical and cosmetic use. Used to stabilize pH in skincare formulations and reduce irritation from acidic or alkaline ingredients.