Isooctyl Thioglycolate
AKA “25103-09-7, Isooctyl mercaptoacetate, Acetic acid, mercapto-, isooctyl ester, Isooctyl 2-mercaptoacetate, 3404M9ZDTB, HSDB 2704, Mercaptoacetic acid, NSC 9590, EINECS 246-613-9
Ingredient
Ingredient Facts
Isooctyl thioglycolate
AKA: 25103-09-7, Isooctyl mercaptoacetate, Acetic acid, Mercapto-, Isooctyl ester, Isooctyl 2-mercaptoacetate, 3404M9ZDTB, HSDB 2704, Mercaptoacetic acid, NSC 9590, EINECS 246-613-9
Ingredient · Hair Waving Or Straightening · EWG: 4
Synthetic
Not Clean
Based on the available data, the CIR Expert Panel concluded that ... Isooctyl Thioglycolate is safe for use in hair straighteners, permanent waves, tonics, dressings, and so forth, wave sets, other non-coloring hair products, and hair dyes and colors, as described in this safety assessment, at concentrations up to 15.2% (as Thioglycolic Acid). Hairdressers should avoid skin contact and minimize consumer skin exposure.
Formula
C10H20O2S
Mol. Weight
204.33
CAS #
25103-09-7
Form
Liquid
State
Liquid
See origin →
Functions
Hair Waving Or Straightening
Antioxidant Protection
Reduces Inflammation
Wound Healing
Changes hair texture
Traditional Use
A synthetic reducing agent developed for use in permanent wave and hair relaxing products. Created to chemically break down hair protein bonds for permanent hair styling.
Skin Types
all-skin-types
Best For
Uneven Texture
Pregnancy & Breastfeeding Safe
Caution
EWG
4
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
medical-approval
all-shades-safe
Mild Irritant
Regulatory Status
USApermitted
EUpermitted
JAPANpermitted
CANADApermitted
Safety Assessment of Tetrasodium Glutamate Diacetate and Beta-Alanine Diacetic Acid as Used in Cosmetics.
Burnett CL, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2025
Safety Assessment of Tetrasodium Glutamate Diacetate and Beta-Alanine Diacetic Acid as Used in Cosmetics.
Burnett CL, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2025
Sodium Dehydroacetate and Dehydroacetic Acid.
Cherian P, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2024
Sodium Dehydroacetate and Dehydroacetic Acid.
Cherian P, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2024
Final Report on the Safety Assessment of Sodium Dehydroacetate and Dehydroacetic Acid
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Safety Assessment of Tetrasodium Glutamate Diacetate and Beta-Alanine Diacetic Acid as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Sodium Dehydroacetate and Dehydroacetic Acid
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Acetic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Beta-Alanine Diacetic Acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
dehydroacetic acid
European Commission
EU Cosmetic Ingredient Database (CosIng)
Isooctyl Thioglycolate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Acetic acid and the skin: a review of vinegar in dermatology.
Elhage KG, St Claire K, Daveluy S
International journal of dermatology, 2022
Acetic acid and the skin: a review of vinegar in dermatology.
Elhage KG, St Claire K, Daveluy S
International journal of dermatology, 2022
Acetic Acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
dehydroacetic acid
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Isooctyl Thioglycolate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Potential application of novel liquid crystal nanoparticles of isostearyl glyceryl ether for transdermal delivery of 4-biphenyl acetic acid.
Fujii MY, Asakawa Y, Fukami T
International journal of pharmaceutics, 2020
Preparation of (13)C-labeled ceramide by acetic acid bacteria and its incorporation in mice.
Fukami H, Tachimoto H, Kishi M, Kaga T, Waki H et al.
Journal of lipid research, 2010
Trichloroacetic acid
Health Canada
Health Canada Cosmetic Ingredient Hotlist
[Pharmacological studies of N-(2-mercapto-2-methylpropionyl)-L-cysteine (SA 96). VI. Effects on vitamin B6, metals and skin collagen in rats].
Yamauchi H, Morikawa K, Kuwano M, Hikida M, Fujimura K et al.
Nihon yakurigaku zasshi. Folia pharmacologica Japonica, 1985
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR