murphyAmmonium Thioglycolate
AKA: 5421-46-5, Ammonium mercaptoacetate, Thioglycolic acid ammonium salt, Thiofaco A-50, Acetic acid, Monoammonium salt, Ammonium thioglycollate, Ammonium sulfanylacetate, USAF MO-2, HSDB 7167
Synthetic
Not Clean
OriginSynthesized from thioglycolic acid and ammonia, both derived from petrochemical feedstocks. Produced through neutralization of thioglycolic acid with aqueous ammonia solution to form the ammonium salt.
Based on the available data, the CIR Expert Panel concluded that ... Ammonium 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.
Solubility Miscible (NTP, 1992)
Formula
C2H7NO2S
Mol. Weight
109.15
CAS #
5421-46-5
Form
Liquid
State
Ammonium thioglycolate is a colorless to faint pink liquid with a repulsive, skunk-like odor. (NTP, 1992)
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
Functions
Depilatory
Hair Waving Or Straightening
Reducing
Moisturizing
Strengthens Barrier
Changes hair texture
Removes unwanted hair
Chemical reduction
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
5
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
Mixed Eye Irritation Results
2 studies / 1 irritating / 1 mixed / reactions moderate (CIR 128 and 347)
Mixed Skin Irritation Results
25 studies / 14 irritating / 3 mixed / 8 not irritating / reactions slight to severe (CIR 128 and 347)
Mixed Sensitization Results
36 studies / 21 sensitizing / 3 mixed / 12 not sensitizing / reactions moderate / plus 7 case reports (CIR 128 and 347)
Dermal Absorption 0.24–22.1%
5 animal studies in the CIR safety assessment (CIR 347)
Regulatory Agencies
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR