EINECS NO. 203-537-0




H.S. CODE 2930.90
TOXICITY Oral rat LD50: 96 mg/kg
SYNONYMS Beta-mercaptopropanoic acid; 3-Thiopropionic acid;
3-Mercaptopropanoic acid; beta-Mercaptopropionic acid; beta-Thiopropionic acid; 3-Thio -Hydracrylic acid; Mercaptopropionic acid; 3-MPA





clear  to pale yellow liquid




87 C

STABILITY Stable under ordinary conditions.


3-Mercaptopropionic acid and its derivatives are main materials for the synthesis of PVC-stabilizers and are used  as chain transfer and cross-linking agents in polymerizations. These compounds are also useful as ion exchange catalysts, coupling agents, and in UV-curable formulations. 3-Mercaptopropionic acid is a clear, near water-white liquid with strong odor used as a basic material in the production of PVC stabilizers. 3,3'-Thiodiproprionic acid and its derivatives are used as a primary or secondary antioxidant and color stabilizer in combination with phenolic antioxidant for polymers including polyolefins, styrenics, rubbers, polyesters and soap industry. They are also used as an intermediate for the synthesis of organic compounds. They are approved to use in food packaging. They can be used as stabilizers in oils, lubricants, sealants, and adhesives. They are active ingredients of biocides can be used in personal care products.



clear  to pale yellow liquid


98.0% min


100ppm max


1ppm max


100 max

PACKING 240kgs in Drum
HAZARD CLASS 8 (Packing Group: III)


European Hazard Symbols: T, Risk Phrases: 25-34, Safety Phrases: 25-28A-36/37/39-45


Mercaptan: any of a class of organosulfur compounds is similar to the alcohol and phenol but containing a sulfur atom in place of the oxygen atom. Compounds containing -SH as the principal group directly attached to carbon are named 'thiols'. In substitutive nomenclature their names are formed by adding '-thiol' as a suffix to the name of the parent compound. When -SH is not the principal group, the prefix 'mercapto-' is placed before the name of the parent compound to denote an unsubstituted -SH group. 'thio'  is a chemical prefix indicates the replacement of an oxygen in an acid radical by sulfur with a negative valence of 2. Sulfur analog of alcohol is called thiol (or mercaptan), and ether analog is called sulfide.

The first chemical contrast of thiols and sulfides with alcohols and ethers is acidity which is important in organic reactions. Thiols are stronger acids than relevant alcohols and phenols. Thiolate conjugate bases are easily formed, and are excellent nucleophiles in SN2 reactions of alkyl halides and tosylates. The nucleophilicity of sulfur is much greater than that of oxygen, resulting in a number of useful electrophilic substitution reaction that are rare by oxygen. For example, sulfides form (with alkyl halides) ternary sulfonium salts, in the same alkylattion of tert-amines quaternary ammonium salts, whereas ternary oxonium salts are prepared only under extream conditions. Without exception, sulfoxides, sulfinate salts and sulfite anion also alkylate on sulfur, despite of the partial negative formal charge on oxygen and partial positive charge on sulfur. The second character is the oxidation states of sulfur. Oxygen has only two oxidation states, whereas sulfur covers from –2 to +6 as follows:

  • -2: Hydrogen Sulfide (H2S), sulfides, sulfonium ions
  • -1: disulfides
  • 0: S elemental, sulfoxides, sulfenic acids
  • +2: sulfones, sulfinic acids
  • +4: sulfonic acids, sulfite esters
  • +6: sulfate esters

One more sulfur compound's contrast with oxygen analog is in oxidation chemistry. Oxidation of sulfur compounds changes the oxidation state of sulfur rather than carbon, whereas, oxidation of  alcohols to aldehydes and ketones changes the oxidation state of carbon not oxygen. Thiols is oxidized to S-S single bond (disufide) which is stronger than O-O bond in peroxide. Disufide forms sulfenyl chlorides (with chlorine in mild condition) or sulfonic acids under harder condition. Oxidation of sulfides with hydrogen peroxide (or peracids) yields sulfoxides and then to sulfones. A certain sulfoxide compound such as dimethyl sulfoxide can be used as an effective oxygen source in the oxidation reaction of primary and secondary alcohols to aldehydes and ketones. DMSO easily is reduced to dimethyl sulfide and water is taken up by the electrophile. oxidation procedure is very mild and tolerates a variety of other functional groups, including those having oxidizable nitrogen and sulfur atoms.

Organosulfur compounds have diverse applications in the organic synthesis as organosulfur sources into target organic molecules in the manufacture of pharmaceuticals, adhesives, biocides, agrochemical products, lubricant and fuel additives for high pressure, surfactants, water treatment chemicals, dyes, flavors & fragrances, and photographic chemicals. 

Sulfonamide is an organic sulfur compounds containing the radical -SO2NH2 (the amides of sulfonic acids). Its molecular structure is similar to p-Aminobenzoic acid (PABA) which is needed in bacteria organisms as a substrate of the enzyme dihydropteroate synthetase for the synthesis of tetrahydrofolic acid (THF). Sulfonamides, derived from chiefly sulfanilamide, are capable of interfering with the metabolic processes in bacteria that require PABA. They act as antimicrobial agents by inhibiting bacterial growth and activity and called sulfa drugs. They are used in the prevention and treatment of bacterial infections, diabetes mellitus, edema, hypertension, and gout.

Thiophene, also known as Thiofuran, is a cyclic compound containing four carbon atoms and one sulphur atom in a ring. It is a toxic, flammable, highly reactive, colorless liquid insoluble in water (soluble in alcohol and ether) and melts at 38 C, boils at 84 C. It is used as a solvent and chemical intermediate. Its derivatives are widely used in manufacturing dyes, aroma compounds and pharmaceuticals. They are used as monomers to make condensation copolymers.

Thiosulfate is a salt containing the negative ion S2O32-, a analog of the sulfate ion (SO42-) where one of the oxygen (O) atoms has been replaced by a sulfur atom. The sulfur atoms of the thiosulfate ion are not equivalent. Thiosulfate is tetrahedral, and the central sulfur is in the formal oxidation state 6+; and the terminal sulfur is in the formal oxidation state 2-. This species is an important reducing agent. Ammonium Thiosulphate is used as the most common component of photographic fixing agent especially for rapid development. It is used as a nitrogen and sulphur fertilizer. It is used to enhance N utilization efficiency of fertilizers such as urea ammonium nitrate. Sodium Thiosulfate is a white translucent crystals or powder that is common as the pentahydrate form; melting at 48 C; readily soluble in water and oil of turpentine; aqueous solution is slightly alkaline which decompose to sulfate and sulfide in the air. It is a moderate reducing agent. Its major use is as a fixing agent in photography for developing film and the extracting silver from ore. It is used in chrome-tanning leather and in chemical manufacture as a source of sulfide ion. It is also used in paper, textile, water treatment industry and gas purification.

Thiocyanate is a salt or ester of thiocyanic acid (HSCN). Aqueous solutions of thiocyanic acid , also called sulfocyanic acid, are very strong acids of the  equilibrium mixture of thiocyanic and isothiocyanic. Thiocyanates are bonded through the sulfur(s) with the structure R-S-C≡N or the isomeric R-N=C=S (isothiocyanates). Thiocyanates are bonded through the sulfur(s) which replace for the oxygen (O) atom. Thiocyanates are the sulfur analog of isocyanates. Organic as well as metallic thiocyanates [CuSCN, Ca(SCN)2, NaSCN, KSCN] are very versatile compounds. They have wide range of applications including manufacturing industrial chemicals, pharmaceuticals and pesticides. It is used in freezing solutions, fabric dyeing, electroplating, steel pickling, printing, and corrosion inhibitor against acid gases. It is used in photography industry as a stabilizer or accelerator.

Thiourea (also called Thiocarbamide or Sulfourea) is the diamide of thiocarbonic acid that resembles urea but contains sulfur instead of oxygen.  In fct, thiourea occurs as the mixture of two tautomers: S=C(NH2)2 ( Thiourea) + HS=CNHNH2 (Isothiourea), accordingly, provides three functional groups (mino, imino, and thiol). Thiourea is a lustrous white crystalline compound; estimated melting point is 170-180 C; soluble in water and in polar organic solvents; insoluble in non-polar solvents. The exact melting point and boiling point are not available since rearrangement to ammonium thiocyanate (NH4SCN) occurs at about 135 C and decomposition occurs. It can be prepared by heating ammonium thiocyanate, or by the addition of hydrogen sulfide to cyanamide. The latter is the more common method. Thiourea is used directly in ore filtering, metal refinery and cleaning, isomerization catalyst (conversion of maleic to fumaric acid) and as an additive in fertilizers (to inhibit the nitrification process), drilling auxiliaries, light-sensitive photocopy paper and explosives.  It is used as a fixing agent in photography, as a liquefying agent in animal hide glue, as an insecticide, as a textile-treating agent, and as an intermediate to produce other compounds. Thiourea and its derivatives are versatile intermediates for the synthesis of modified thermosetting resins, thiourea dioxide, dyes, flame retardants, vulcanization accelerators, plant protection agents, pesticides, amino resins, peptizing agents, fungicides, hair preparations, dry cleaning chemicals, corrosion inhibitors and thiazole drugs (e.g., antiseptic, thyrotherapeutic, narcotic, and tuberculostatic agents). Dithiobiurea possesses a wide dipole moment and thus is involved in the forming wide metal chelated complexes as the radioactiv-compound which used in radiopharmaceutical imaging, inhibiting enzyme function, kidney function study and to treat toxic metal poisoning. It is used in co-crystals development used in the field of nonlinear optics to generate new coherent wavelengths.

Thioglycolic acid, a simple sulfur group- chained carboxylic acid, is a clear liquid; melts at -16. c, boils at 96 C; soluble in water. It is an useful chemical intermediate in the chemical reactions such as addition, elimination and cyclization. Sulfur group will react with bases, acids, ketoness and organic halogen compounds, whereas the carboxylic group will preferentially react In the presence of alcohols or amines. The applications of thioglycolic acid and its derivatives are wide in the fields of of PVC stabilizers, down-hole acidizing, corrosion inhibition in the oil field industry, manufacturing of pharmaceuticals, agrochemicals and dyes, hair care products (waving, hair removal and hair straightening), shrink-resistant treatment of wool, fabric dying, leather processing.

Isethionic acid, short chain alkan sulfonate containing hydroxy group, is a water soluble liquid used in the manufacture of mild, biodegradable and high foaming anionic surfactants which provides gentle cleansing and soft skin feel.