Sodium Thioglycolate: Uses, Properties, and Sourcing Guide (CAS 367-51-1)

Sodium thioglycolate (CAS 367-51-1) is the sodium salt of thioglycolic acid — a white, water-soluble crystalline powder best known in three industries: as the active depilatory chemical and perm-solution raw material in cosmetics, as a rubber accelerator in polymer and rubber processing, and, under the abbreviation STG, as a flotation depressant for copper-molybdenum separation in mineral processing.

What Is Sodium Thioglycolate? Names, Synonyms, and Chemical Identity

Sodium thioglycolate (also spelled sodium thioglycollate) is sold under several interchangeable names, and knowing them helps when you compare quotes from different suppliers:

Chemically it is the monosodium salt of mercaptoacetic acid (thioglycolic acid): a small molecule with a thiol (–SH) group and a carboxylate (–COONa) group, which explains both its signature sulfur odor and its ability to break disulfide bonds.

Key Properties of Sodium Thioglycolate

The two most important grades on the market are industrial grade sodium thioglycolate (for mineral processing, rubber, and chemical synthesis) and sodium thioglycolate cosmetic grade (for personal-care applications, with strict limits on heavy metals and impurities).

What Is Sodium Thioglycolate used for?

1. Cosmetic Grade Sodium Thioglycolate: Depilatory Chemical & Perm Solution Raw Material

The best-known consumer use of sodium thioglycolate is in hair removal products. As a sodium thioglycolate depilatory chemical, it works by a simple but elegant mechanism: hair keratin is held together by disulfide (–S–S–) bonds, and the thiol group of sodium thioglycolate reduces those bonds to –SH groups. The hair shaft softens and swells, after which it can be wiped or scraped away with minimal skin irritation — which is why it is a core sodium thioglycolate hair removal raw material for depilatory creams, lotions, and wax-free hair removers.

The same chemistry powers the salon and home perm solution market. Cold-wave permanent wave lotions contain thioglycolate salts — including sodium thioglycolate for perm solution — that break the keratin disulfide bonds so the hair can be re-shaped, after which a neutralizer re-forms the bonds in the new shape.

2. Industrial Grade: STG Flotation Depressant for Copper-Molybdenum Separation

In the mining industry, sodium thioglycolate is better known by its abbreviation STG — short for Sodium ThioGlycolate. It is one of the most widely used STG flotation depressants in modern copper-molybdenum (Cu-Mo) separation circuits.

How sodium thioglycolate works in flotation?

During bulk flotation, copper sulfide minerals (mainly chalcopyrite) and molybdenite are floated together. The separation step must then depress the copper minerals so that only molybdenite floats. Sodium thioglycolate does exactly that:

● It adsorbs selectively onto copper and iron sulfide mineral surfaces, making them hydrophilic and preventing them from attaching to air bubbles.

● Molybdenite — naturally hydrophobic — is left free to float and be recovered as a clean concentrate.

● Dosing is simple and can be adjusted inline to match ore variability.

3. Rubber Accelerator & Polymer Applications

In the rubber and polymer industries, sodium thioglycolate finds a smaller but steady market as a rubber accelerator and processing aid. Its thiol functionality participates in vulcanization chemistry, helping to speed up or moderate the cross-linking of rubber compounds in certain formulations, and it can also act as a processing aid that improves compound consistency. Related thioglycolate derivatives are likewise used as chain-transfer agents in emulsion and solution polymerization to control molecular weight — a family of applications that keeps demand for the sodium salt stable alongside the bigger cosmetic and mining markets.

4. Chemical Intermediate, Reducing Agent & Laboratory Use

Finally, sodium thioglycolate is a versatile building block and reducing agent:

Organic synthesis

● — the thiol group makes it a convenient intermediate for thioesters, thioethers, and other sulfur-containing fine chemicals.

Reducing agent / oxygen scavenger

● — it is used in some industrial and laboratory processes to scavenge oxygen and maintain reducing conditions.

Microbiology

● — under the spelling sodium thioglycollate, it is the standard reducing agent in fluid thioglycollate medium (FTM), the classic culture medium for testing anaerobes and sterility.

Sodium Thioglycolate Supplier & Manufacturer: What to Check Before Buying

If you want to buy sodium thioglycolate — whether a single drum for trials or sodium thioglycolate bulk quantities for production — the market is served by dedicated sodium thioglycolate manufacturers and chemical distributors. Because the compound is also sold as sodium mercaptoacetate or thioglycolic acid sodium salt, the same product may appear under different names on different supplier catalogs; search all three when comparing.

Key factors that determine sodium thioglycolate price

Checklist when contacting a sodium thioglycolate supplier or manufacturer

1. Request the COA (Certificate of Analysis) for the exact batch — verify assay and heavy-metal limits against your application (cosmetic vs industrial).

2. Confirm the grade matches your use: cosmetic grade for depilatory and perm formulations; industrial grade for flotation, rubber, and synthesis.

3. Ask about packaging and shelf life— moisture exposure degrades the powder.

4. Compare bulk pricing and logistics— for flotation plants, delivered cost per ton matters more than unit price.

5. Verify compliance documents(SDS, REACH/ECHA status, transport classification) before committing.

Whether you are a formulator looking for thioglycolic acid sodium salt buy options, a mining plant sourcing STG depressant, or a trader comparing sodium mercaptoacetate supplier and sodium mercaptoacetate manufacturer quotes, the same rule applies: match the grade to the application and verify every batch with a COA.

Sodium Thioglycolate vs Thioglycolic Acid

Buyers frequently confuse the sodium salt with its parent acid. They are closely related but not interchangeable:

In practice, most downstream applications — cosmetics, flotation, rubber — consume the salt form, which is why sodium thioglycolate CAS 367-51-1 is the specification buyers search for.

Safety and Handling

Odor:the characteristic mercaptan smell can be unpleasant; handle in ventilated areas.

Skin/eye contact:may cause irritation; wear gloves and goggles.

Hygroscopicity:keep containers sealed and store in a cool, dry place.

Compliance:always obtain the SDS from your supplier and follow local chemical handling and transport regulations.

FAQ

1. Is sodium thioglycolate the same as thioglycolic acid? 

No. Sodium thioglycolate (CAS 367-51-1) is the sodium salt of thioglycolic acid (CAS 68-11-1): the acid is a corrosive liquid, while the salt is a white powder that is easier to handle and is the form used in most finished applications.

2. What is sodium thioglycolate used for? 

Its three main uses are depilatory and perm products in cosmetics, the STG flotation depressant in copper-molybdenum separation, and rubber accelerator / polymer processing applications, plus chemical synthesis and microbiology media.

3. What does STG stand for in mining? 

STG is the abbreviation for Sodium ThioGlycolate, a flotation depressant used to selectively depress copper and iron sulfide minerals so that molybdenite can be floated and recovered in Cu-Mo separation circuits.

4. How does sodium thioglycolate work in copper-molybdenum separation?

It adsorbs onto copper and iron sulfide surfaces, making them hydrophilic so they stay in the tailings, while the naturally hydrophobic molybdenite continues to float — achieving clean copper-molybdenum separation without cyanide.

5. Is sodium thioglycolate a rubber accelerator? 

Yes. In rubber and polymer processing it is used as a rubber accelerator and processing aid, and thioglycolate derivatives also serve as chain-transfer agents in polymerization.

6. What is the sodium thioglycolate CAS number? 

Sodium thioglycolate has CAS number 367-51-1.

7. Where can I buy sodium thioglycolate in bulk? 

From dedicated sodium thioglycolate manufacturers and chemical distributors. Search for sodium thioglycolate supplier, sodium mercaptoacetate supplier, or thioglycolic acid sodium salt suppliers, and compare COA, grade, bulk price, and logistics.

8. What is the difference between cosmetic grade and industrial grade sodium thioglycolate? 

Cosmetic grade has tighter purity and heavy-metal limits for skin-contact products (depilatories, perms); industrial grade is used for mineral processing, rubber, and synthesis where those limits are less critical — and it is usually cheaper.

Conclusion

Sodium thioglycolate (CAS 367-51-1) — also known as sodium mercaptoacetate, thioglycolic acid sodium salt, or simply STG — is one of those quiet workhorse chemicals that appears in products as different as hair-removal cream, perm lotion, rubber compounds, and molybdenum concentrators. Its thiol chemistry is the common thread: breaking disulfide bonds for cosmetics, depressing sulfide minerals in flotation, and accelerating rubber chemistry in polymer processing.

For buyers, the practical takeaways are simple: match the grade (cosmetic vs industrial) to your application, verify every batch with a COA, and compare sodium thioglycolate supplier offers on delivered bulk cost rather than unit price alone. Whether you are formulating a depilatory, running a Cu-Mo flotation circuit, or compounding rubber, sodium thioglycolate is a versatile, proven, and increasingly preferred choice.

Sources

● PubChem, CID 23690444 — Sodium 2-sulfanylacetate (molecular formula C₂H₃NaO₂S, molecular weight 114.10):

https://pubchem.ncbi.nlm.nih.gov/compound/23690444

● ChemicalBook — Sodium thioglycolate (CAS 367-51-1) database record

● U.S. EPA / ECHA regulatory databases — thioglycolic acid and its salts registration and hazard profiles

● Cosmetics industry references — thioglycolate salts in depilatory and permanent-wave formulations