Thiodipropionic Acid
AKA “3, 3'-Thiodipropionic acid, 111-17-1, Tyox A, TDPA, Propanoic acid, 3'-thiobis-, Bis(2-carboxyethyl) sulfide, Thiodihydracrylic acid, 4-Thiaheptanedioic acid, Sulfide, bis(2-carboxyethyl)”
Acid
Ingredient Facts
Thiodipropionic acid
AKA: 3, 3'-Thiodipropionic acid, 111-17-1, Tyox A, TDPA, Propanoic acid, 3'-thiobis-, Bis(2-carboxyethyl) sulfide, Thiodihydracrylic acid, 4-Thiaheptanedioic acid, Sulfide, Bis(2-carboxyethyl)
Acid · Skin Conditioning · EWG: 1
Synthetic
Skin Conditioner
Acid
Clean
The CIR Expert Panel concludes that Dilauryl Thiodipropionate, Thiodipropionic Acid, Dicetyl Thiodipropionate, Dimyristyl Thiodipropionate, Distearyl Thiodipropionate, and Ditridecyl Thiodipropionate are safe as cosmetic ingredients in the practices of use and concentration given in this safety assessment when formulated to be non-irritating.
Solubility FREELY SOL IN HOT WATER, ALC, ACETONE; 1 G DISSOLVES IN 26.9 ML WATER @ 26 °C
Formula
C6H10O4S
Mol. Weight
178.21
CAS #
111-17-1
Form
Liquid
State
Dry Powder
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.
Locks in moisture
Traditional Use
Synthetic antioxidant developed in the 20th century for cosmetic and food preservation. Created to prevent rancidity and oxidative degradation in formulations containing oils.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
Final Safety Assessment of Thiodipropionic Acid and its Dialkyl Esters as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Thiodipropionic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Final safety assessment of thiodipropionic acid and its dialkyl esters as used in cosmetics.
Diamante C, Fiume MZ, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2010
Final safety assessment of thiodipropionic acid and its dialkyl esters as used in cosmetics.
Diamante C, Fiume MZ, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2010
Final safety assessment of thiodipropionic acid and its dialkyl esters as used in cosmetics.
Diamante C, Fiume MZ, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2010
Final safety assessment of thiodipropionic acid and its dialkyl esters as used in cosmetics.
Diamante C, Fiume MZ, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2010
Final safety assessment of thiodipropionic acid and its dialkyl esters as used in cosmetics.
Diamante C, Fiume MZ, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2010
Final safety assessment of thiodipropionic acid and its dialkyl esters as used in cosmetics.
Diamante C, Fiume MZ, Bergfeld WF, Belsito DV, Hill RA et al.
International journal of toxicology, 2010
Thiodipropionic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Alkali earth metal sulfides
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Alkali sulfides
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Carbon disulfide
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR