Mercaptoacetic acid
Synonyms
Acetic acid, 2-mercapto-;
Acetic acid, mercapto-;
Thioglycolic acid;
Category
Anionic Surfactant
> Carboxylate
>> Chain Carboxylate
>>> Mercapto Alkyl Carboxylate
>>>> Mercapto Linear Alkyl Carboxylate
Chemical Numbering System
CAS: 68-11-1
EINECS: 200-677-4
Molecular Formula & Molecular Weight
Molecular Formula: C2H4O2S
Molecular Weight: 92.12
Structure
Properties
Appearance (1), colorless to pale yellow liquid.
Odor strong pungent unpleasant odor.
Solubility soluble in water.
Stability stable. Easily oxidized.
Risk Liquid form: flammable material; irritation, irritation to skin, eye, respiratory system. Harmful products of combustion are CO, CO2 and so on. Contact with strong oxidants, can cause to burn.
GHS label: 
Animal Toxicity
Table 1 Animal toxicity values
|
guinea pig intraperitoneal LD50 |
157mg/kg[1] |
|
guinea pig oral LD50 |
126mg/kg[1] |
|
mouse inhalation LCLo |
7mg/m3/2H[1] |
|
mouse intraperitoneal LD50 |
138mg/kg[1] |
|
mouse intravenous LD50 |
145mg/kg[1] |
|
mouse oral LD50 |
242mg/kg[1] |
|
mouse skin LD50 |
47mg/kg[1] |
|
rabbit intravenous LD50 |
100mg/kg[1] |
|
rabbit oral LD50 |
119mg/kg[1] |
|
rabbit skin LDLo |
300mg/kg[1] |
|
rat inhalation LC50 |
210mg/m3/4H[1] |
|
rat intraperitoneal LD50 |
70mg/kg[1] |
|
rat oral LD50 |
114mg/kg[1] |
Ecology may be hazardous to environment. Water body should be given special attention.
Biodegradability biodegradable.
Characteristics excellent anti-oxidizing, dispersing, depilatory, chelating abilities.
Synthesis
Quality Standards & Test Methods
1, Physical and chemical indexes
|
Item |
Physical and chemical indexes |
|
Liquid |
|
|
Actives, %, ≥ |
95.0 |
Test Methods
(1), Actives
GB/T 13173 Surface active agents -- Detergents -- Testing methods
2, Hazardous substances indexes
|
Item |
Hazardous substances indexes |
|
Liquid |
|
|
Heavy metals (as Pb), mg/kg, ≤ |
20 |
|
As, mg/kg, ≤ |
3 |
Test Methods
(1), Heavy metals (as Pb)
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30799 The test method of food detergents -- Determination of heavy metals
(2), As
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30797 The test method of food detergents -- Determination of total arsenic
3, Further explanation
(a), On physical and chemical indexes: firstly, shall be indicated carbon atom distribution; secondly, shall be indicated average molecular weight.
(b), Used in cosmetics, should be test for harmful substances or furtherly test for microorganisms, according to local regulations and standards.
Major Uses
1, Typical applications
Use as antioxidant.
2, Personal care products
Epilating agent, reducing agent, antioxidant, hair waving or straightening agent in personal care products.
* * * * * *
Further information:
(1), In accordance with EU regulations (EC) No 1223/2009, directive 88/233/EEC, be included in Annex III/2a.
Can be applied to:
(1a), Hair products
General use: Maximum concentration is 8% (as thioglycolic acid), pH 7 to 9.5.
Professional use: Maximum concentration is 11% (as thioglycolic acid), pH 7 to 9.5.
(1b), Depilatories
Maximum concentration is 5% (as thioglycolic acid), pH 7 to 12.7.
(1c), Hair rinse-off products
Maximum concentration is 2% (as thioglycolic acid), pH 7 to 9.5.
(1d), Products intended for eyelash waving
Maximum concentration is 11% (as thioglycolic acid), pH 7 to 9.5.
(2), In accordance with Safety and Technical Standards for Cosmetics (2015 Edition) of China, be included in the restricted components.
Can be applied to:
(1a), Hair products
General use: Maximum concentration is 8% (as thioglycolic acid), pH 7 to 9.5.
Professional use: Maximum concentration is 11% (as thioglycolic acid), pH 7 to 9.5.
(1b), Depilatories
Maximum concentration is 5% (as thioglycolic acid), pH 7 to 12.7.
(1c), Hair rinse-off products
Maximum concentration is 2% (as thioglycolic acid), pH 7 to 9.5.
3, Organic synthesis
Use as intermediate in organic synthesis.
Use as carbonyl condensation catalyst.
Manufacturers
References
[1]: ChemIDplus. 68-11-1, Mercaptoacetic acid
Update: 20140209(1); 20180917(2);