12-HYDROXY STEARIC ACID

12-Hydroxy stearic acid (12-HSA) is a saturated hydroxy fatty acid derived from the hydrogenation of ricinoleic acid in castor oil, with chemical formula C₁₈H₃₆O₃, molecular weight 300.48 g/mol, CAS number 106-14-9, EC number 203-366-1, EINECS 203-366-1, MDL MFCD00004592, BRN 1726730, DTXSID8026725, HSDB 5368, FDA UNII 933ANU3H2S, ChEBI CHEBI:85208, CHEMBL292352, COSING REF 34555, UNSPSC 41116107, NACRES NA.24, SMILES CCCCCCC(O)CCCCCCCCCCC(O)=O, InChIKey ULQISTXYYBZJSJ-UHFFFAOYSA-N, pKa 4.78±0.10 (predicted), LogP 5.7.
It appears as cream-coloured or white flakes, powder, or waxy solid with no significant odour or taste; melting point 74–76°C (lit.; commercial range 70–80°C), density 1.0238 g/cm³ (rough estimate), refractive index 1.4200 (estimate), vapour pressure 0 Pa at 20°C, insoluble in water, soluble in ethanol, ether, chloroform, methanol, DMF, and DMSO.
12-Hydroxy stearic acid is produced commercially by hydrogenation of crude castor oil at 5 MPa and 185°C in the presence of a nickel-aluminium catalyst, followed by saponification, acid hydrolysis, cooling, crystallisation, filtration, and drying; it is biodegradable, derived from a renewable castor oil feedstock, and is approved under FDA 21 CFR 176.170, 176.180, 176.210, and 178.3570 for food-contact applications.

CAS Number: 106-14-9
EC Number: 203-366-1
Molecular Formula: C₁₈H₃₆O₃
Molecular Weight: 300.48 g/mol
MDL Number: MFCD00004592

Synonyms: 12-HSA, 12-HODA, 12-Hydroxyoctadecanoic acid, 12-Hydroxy-octadecanoic acid, Octadecanoic acid 12-hydroxy-, DL-12-Hydroxystearic acid, DL-12-Hydroxyoctadecanoic acid, Stearic acid 12-hydroxy-, Hydroxystearic acid, 12-Hydroxystearic acid, Cerit Fac 3, Hydrofol Acid 200, Ceroxin GL, Barolub FTO, Loxiol G 21, Harwax A, NSC 2385, NSC-2385, BRN 1726730, MFCD00004592, DTXSID8026725, FDA UNII 933ANU3H2S, ChEBI CHEBI:85208, CHEMBL292352, AI3-19730, SCHEMBL17773, EINECS 203-366-1, CAS 106-14-9

A cream-coloured to white, odourless, waxy solid at room temperature, 12-hydroxy stearic acid differs from stearic acid by a single secondary hydroxyl group at carbon-12 of the C₁₈ chain — a structural detail that fundamentally alters its physical behaviour and industrial utility, enabling both its carboxylic acid terminus and its mid-chain hydroxyl group to participate simultaneously in diverse chemical reactions including esterification, salt formation, and hydrogen-bond-mediated self-assembly.
The presence of the C-12 hydroxyl group is responsible for 12-hydroxy stearic acid's ability to form fibrillar self-assembled networks in organic solvents and oils — a property that underpins its function as a gelling agent across lubricant, cosmetic, ink, and adhesive applications — and for the excellent thickening performance of its lithium soap derivative (lithium 12-hydroxystearate) in high-performance multi-purpose greases.

Uses of 12-Hydroxy Stearic Acid:
12-Hydroxy stearic acid is used as the principal fatty acid feedstock for the manufacture of lithium 12-hydroxystearate — the primary thickener in lithium and lithium complex multi-purpose greases — by saponification with lithium hydroxide monohydrate; the resulting lithium soap imparts outstanding mechanical stability, high drop point, excellent water resistance, and a wide service temperature range to the finished grease, making lithium 12-hydroxystearate the global standard for automotive and industrial multi-purpose grease thickeners; 12-HSA is also used to manufacture barium and calcium soap greases with excellent resistance to water, oils, solvents, and crude petroleum.
12-Hydroxy stearic acid is used as a gelling agent for mineral oils, liquid paraffin, synthetic esters, and some silicone oils in cream, ointment, and cosmetic formulations, where it forms a fibrillar self-assembled network at low concentrations (1–5%) without chemical crosslinking; it is used in the formulation of antiperspirant and deodorant sticks, gel lipsticks, hair styling waxes, shaving creams, skin creams, and lotions as a structuring and gelling agent, emollient, skin-conditioning agent, surfactant, and viscosity builder; INCI: HYDROXYSTEARIC ACID; cosmetic functions: cleansing, emollient, skin conditioning, surfactant-emulsifying, surfactant-cleansing.

12-Hydroxy stearic acid is used as a chemical intermediate in the synthesis of esters of 12-HSA — including isopropyl 12-hydroxystearate, octyl 12-hydroxystearate, and polyglyceryl 12-hydroxystearate — used in cosmetic and personal care products as emollients, skin-conditioning agents, and emulsifiers; it is also used as an intermediate in pharmaceutical synthesis (excipients for insulin formulation, anticancer drug carriers, antihypertensive drug formulations) and in agrochemical synthesis.
12-Hydroxy stearic acid is used in coatings chemistry, where it is reacted with acrylic esters (acrylation of the C-12 hydroxyl group) to produce hard, durable thermosetting acrylic polymers used in high-quality automotive finishes, industrial appliance coatings, and metal decorative coatings; it is also used as a dispersant, wetting agent, and adhesion promoter in specialty coating and ink formulations and in polishes, printing inks, and hot-melt adhesives.
12-Hydroxy stearic acid is used as an activator and internal lubricant for natural and synthetic rubbers — improving the dispersion of fillers and vulcanisation agents and reducing mould sticking — and as a processing aid and mould-release agent in PVC and thermoplastic processing; it is also used as a component in wax blends for candles and surface polishes, and as a corrosion inhibitor precursor in anti-rust grease formulations.

Benefits and Advantages of 12-Hydroxy Stearic Acid:
12-Hydroxy stearic acid is derived from castor oil — a renewable, non-food-competing vegetable oil produced on marginal land — making it one of the few high-volume industrial fatty acids with a fully bio-based supply chain; it is biodegradable, non-irritating, and approved for food-contact applications (FDA 21 CFR), compatible with sustainability and safety requirements of personal care, food packaging, and pharmaceutical industries.
The bifunctionality of 12-HSA — a carboxylic acid at C-1 and a secondary hydroxyl at C-12 — gives it dual reactivity irreplaceable in its key applications: the carboxylic acid group reacts with metal hydroxides to give soap thickeners for greases, while the C-12 hydroxyl group enables self-assembly into fibrillar networks for organogel applications, acrylation for thermosetting coatings, and derivatisation to cosmetic esters — a combination of functionalities not available from unsubstituted fatty acids.
Lithium 12-hydroxystearate greases prepared from 12-HSA are the global standard for multi-purpose automotive and industrial greases due to their unique combination of high drop point (>170°C), excellent mechanical stability, outstanding water resistance, and compatibility with a wide range of base oils; the performance of the finished grease is directly determined by the purity and specification of the 12-HSA feedstock.

Features of 12-Hydroxy Stearic Acid:
12-Hydroxy stearic acid is a cream-coloured to white crystalline flake or powder at room temperature, odourless and tasteless; melting point 74–76°C (lit.); boiling point 180°C; density 1.0238 g/cm³ (rough estimate); refractive index 1.4200 (estimate); vapour pressure 0 Pa at 20°C; pKa 4.78±0.10; LogP 5.7; water-insoluble; soluble in ethanol, ether, chloroform, methanol, DMF (10 mg/mL), DMSO (10 mg/mL); SMILES CCCCCCC(O)CCCCCCCCCCC(O)=O; InChIKey ULQISTXYYBZJSJ-UHFFFAOYSA-N.
Commercial specification (typical): appearance — creamish flakes or powder; acid value ≥175 mgKOH/g; hydroxyl value ≥150 mgKOH/g; iodine value (Wijs) ≤5 g I₂/100 g; saponification value 175–190 mgKOH/g; colour (Gardner) ≤6; colour (1" Lovibond) max 20 yellow / 4.5 red; melting point min. 70°C; purity ≥80% (GC, industrial) to ≥99% (pharmaceutical/analytical).
12-Hydroxy stearic acid is chemically amphoteric — it behaves both as a fatty acid (carboxylic acid terminus, pKa ~4.78) and as a secondary alcohol (C-12 hydroxyl), making it susceptible to esterification, saponification, and acrylation; the hydroxyl group is susceptible to elimination at high temperatures; it self-assembles into fibrillar aggregates in organic media through intermolecular hydrogen bonding of the C-12 hydroxyl groups.

Chemical Properties of 12-Hydroxy Stearic Acid:
12-Hydroxy stearic acid has IUPAC name 12-hydroxyoctadecanoic acid, CAS 106-14-9, molecular formula C₁₈H₃₆O₃, molecular weight 300.48 g/mol, InChI=1S/C18H36O3/c1-2-3-4-11-14-17(19)15-12-9-7-5-6-8-10-13-16-18(20)21/h17,19H,2-16H2,1H3,(H,20,21), InChIKey ULQISTXYYBZJSJ-UHFFFAOYSA-N; EC 203-366-1; MDL MFCD00004592; BRN 1726730; ChEBI CHEBI:85208; CHEMBL292352; DTXSID8026725; FDA UNII 933ANU3H2S.
Key chemical reactions: (1) saponification with LiOH·H₂O → lithium 12-hydroxystearate (grease thickener); (2) saponification with Ca(OH)₂ or Ba(OH)₂ → calcium or barium soap; (3) esterification of the carboxylic acid group with alcohols → 12-hydroxy fatty acid esters; (4) acrylation of the C-12 hydroxyl group → acrylate ester monomer for thermosetting coatings; (5) self-assembly via C-12 hydroxyl hydrogen bonding → fibrillar organogel networks; (6) production route: hydrogenation of crude castor oil at 5 MPa/185°C (Ni-Al catalyst) → saponification → acid hydrolysis → 12-HSA.
12-Hydroxy stearic acid is stable under normal ambient storage conditions; susceptible to saponification by alkali metal hydroxides and to hydroxyl elimination at elevated temperatures; incompatible with strong oxidising agents and strong mineral acids at elevated temperature; store at ≤15°C (room temperature) for industrial storage or −20°C for long-term archival.

Production of 12-Hydroxy Stearic Acid:
12-Hydroxy stearic acid is produced commercially by hydrogenation of crude castor oil at high pressure (5 MPa) and temperature (185°C) in the presence of a nickel-aluminium (Raney nickel or similar) catalyst; the ricinoleic acid in castor oil (~85–90%) is hydrogenated to give 12-HSA by saturation of the C-9/10 double bond while retaining the C-12 secondary hydroxyl group; the product is saponified and acid-hydrolysed, then purified by cooling, crystallisation, filtration, and drying.
Commercial 12-HSA is available in: industrial grade (acid value ≥175, hydroxyl value ≥150, Gardner ≤6, purity ≥80% GC); refined grade (≥85–95%); pharmaceutical/analytical grade (≥99%, USP Reference Standard); packaging: 25 kg PE-lined woven bags; 200 kg steel drums; bulk; storage: ≤15°C (recommended), away from heat, moisture, and oxidising agents.

12-Hydroxy Stearic Acid Material Safety Data Sheet (MSDS):

Handling of 12-Hydroxy Stearic Acid:
12-Hydroxy stearic acid is a combustible solid at elevated temperature; avoid generating and inhaling dust; wear dust mask, safety glasses, and gloves for powder handling; keep away from open flames and heat sources above the melting point; avoid prolonged skin and eye contact; wash hands thoroughly after handling; do not eat, drink, or smoke during handling.
At and above its melting point (74–76°C), 12-HSA forms a low-viscosity melt — the molten material presents a thermal burn hazard; use heat-resistant PPE for hot-melt operations; avoid overheating during processing as the C-12 hydroxyl group is susceptible to elimination at high temperatures.

12-Hydroxy Stearic Acid SDS:

Stability and Reactivity of 12-Hydroxy Stearic Acid:

Chemical stability:
12-Hydroxy stearic acid is stable under normal ambient storage conditions.
The C-12 hydroxyl group is susceptible to elimination at elevated temperatures; susceptible to saponification by alkali metal hydroxides.

Reactivity:
Reacts with LiOH, Ca(OH)₂, and Ba(OH)₂ to give the corresponding metal soap thickeners.
Incompatible with strong oxidising agents and strong mineral acids at elevated temperature.

Conditions to avoid:
Strong oxidising agents.
Strong alkali at elevated temperature.
Elevated temperatures (>150°C) — hydroxyl elimination risk.
Open flames and ignition sources — combustible solid/liquid.

Incompatible materials:
Strong oxidising agents.
Strong inorganic bases at elevated temperature.
Strong mineral acids at elevated temperature.

Hazardous decomposition products:
CO and CO₂ upon combustion.
At elevated temperature: dehydration products from C-12 hydroxyl elimination.

Handling and Storage of 12-Hydroxy Stearic Acid:

Handling:
Handle in a well-ventilated area; wear dust mask, safety glasses, and gloves for powder handling.
Avoid dust generation; avoid prolonged skin contact.
Keep away from open flames and heat sources; wash hands after handling.

Storage:
Store at ≤15°C (room temperature recommended), away from heat, direct sunlight, and oxidising agents.
Packaging: 25 kg PE-lined woven bags; 200 kg steel drums; bulk.

First Aid Measures for 12-Hydroxy Stearic Acid:

Inhalation: Move to fresh air; consult a physician if respiratory irritation persists.
Skin contact: Rinse with water; wash with soap and water; for molten material contact, cool immediately with water.
Eye contact: Rinse with plenty of water for at least 15 minutes; consult a physician if irritation persists.
Ingestion: Rinse mouth; give water; seek medical advice.

Firefighting Measures for 12-Hydroxy Stearic Acid:

Suitable extinguishing media: CO₂, dry chemical, foam, water spray.
Specific hazards: Combustible solid/liquid above melting point; dust may form explosive mixtures in air; combustion produces CO and CO₂.
Protective equipment for firefighters: SCBA and full protective clothing.

Accidental Release Measures for 12-Hydroxy Stearic Acid:

Personal precautions: Wear dust mask, gloves, and safety glasses; prevent dust generation.
Environmental precautions: Biodegradable; low environmental hazard; prevent large quantities from entering watercourses.
Clean-up: Collect by sweeping or vacuuming; dispose per applicable regulations.

Exposure Controls / Personal Protective Equipment for 12-Hydroxy Stearic Acid:

Engineering controls: Local exhaust ventilation for powder handling; general ventilation for routine handling.
Eye protection: Safety glasses; splash goggles for molten material.
Hand protection: Nitrile or heat-resistant gloves.
Respiratory protection: Dust mask (P2) for powder handling.

12-Hydroxy Stearic Acid Identifiers:
CAS Number: 106-14-9
EC Number: 203-366-1
EINECS: 203-366-1
MDL Number: MFCD00004592
BRN (Beilstein/Reaxys): 1726730
FDA UNII: 933ANU3H2S
ChEBI: CHEBI:85208
CHEMBL: CHEMBL292352
DTXSID: DTXSID8026725
HSDB: 5368
COSING REF: 34555
UNSPSC: 41116107
NACRES: NA.24
IUPAC Name: 12-Hydroxyoctadecanoic acid
Molecular Formula: C₁₈H₃₆O₃
Molecular Weight: 300.48 g/mol
SMILES: CCCCCCC(O)CCCCCCCCCCC(O)=O
InChI: InChI=1S/C18H36O3/c1-2-3-4-11-14-17(19)15-12-9-7-5-6-8-10-13-16-18(20)21/h17,19H,2-16H2,1H3,(H,20,21)
InChIKey: ULQISTXYYBZJSJ-UHFFFAOYSA-N
pKa: 4.78±0.10 (predicted)
LogP: 5.7
Melting point: 74–76°C (lit.)
Density: 1.0238 g/cm³ (rough estimate)
FDA: 21 CFR 176.170; 176.180; 176.210; 178.3570
Origin: Bio-based (castor oil derived)

Properties of 12-Hydroxy Stearic Acid:
Physical state: Solid (crystalline flakes/powder)
Appearance: Cream-coloured to white flakes, powder, or waxy solid; odourless, tasteless
Molecular formula: C₁₈H₃₆O₃
Molecular weight: 300.48 g/mol
Melting point: 74–76°C (lit.); 70–80°C (commercial)
Boiling point: 180°C
Density: 1.0238 g/cm³ (rough estimate)
Vapour pressure: 0 Pa (20°C)
pKa: 4.78±0.10 (predicted)
LogP: 5.7
Water solubility: Insoluble
Solubility: Ethanol, ether, chloroform, methanol, DMF, DMSO
InChIKey: ULQISTXYYBZJSJ-UHFFFAOYSA-N
FDA: 21 CFR 176.170; 176.180; 176.210; 178.3570
Origin: Bio-based (castor oil)
Storage: ≤15°C; away from heat, moisture, oxidants

12-Hydroxy Stearic Acid — Specifications:
Product name: 12-Hydroxy stearic acid (12-HSA)
CAS Number: 106-14-9
EC Number: 203-366-1
Molecular Formula: C₁₈H₃₆O₃
Molecular Weight: 300.48 g/mol
Appearance: Creamish flakes or powder
Acid value: ≥175 mgKOH/g
Hydroxyl value: ≥150 mgKOH/g
Iodine value (Wijs): ≤5 g I₂/100 g
Saponification value: 175–190 mgKOH/g
Colour (Gardner): ≤6
Colour (1" Lovibond): max 20 yellow / 4.5 red
Melting point: min. 70°C
Purity (GC): ≥80% (industrial); ≥85–99% (refined/pharma grades)
Storage: ≤15°C; cool, dry; away from heat, oxidants
Packaging: 25 kg PE-lined woven bags; 200 kg steel drum; bulk
Documents: CoA, SDS, FDA compliance documentation

Names of 12-Hydroxy Stearic Acid:
12-Hydroxy stearic acid
12-HSA
12-HODA
12-Hydroxyoctadecanoic acid
12-Hydroxy-octadecanoic acid
DL-12-Hydroxystearic acid
DL-12-Hydroxyoctadecanoic acid
Octadecanoic acid, 12-hydroxy-
Stearic acid, 12-hydroxy-
Hydroxystearic acid
12-Hydroxystearic acid
Cerit Fac 3
Hydrofol Acid 200
Ceroxin GL
Barolub FTO
Loxiol G 21
Harwax A
KOW
NSC 2385
NSC-2385
BRN 1726730
MFCD00004592
DTXSID8026725
FDA UNII 933ANU3H2S
ChEBI CHEBI:85208
AI3-19730
EINECS 203-366-1
CAS 106-14-9