STEARYL ALCOHOL

CAS Number: 112-92-5
EC Number: 204-017-6 (EINECS 204-017-6)
Molecular Formula: C18H38O (Condensed Structural Formula: CH3(CH2)16CH2OH or CH3(CH2)17OH)
Molecular Weight: 270.49 g/mol (Exact Monoisotopic Mass: 270.2923 g/mol)
INCI Name: STEARYL ALCOHOL
E Number: Not Applicable as a direct E-number food additive (Authorized indirect food additive and defoaming/lubricating/coating substance under US FDA 21 CFR 172.864 Synthetic Fatty Alcohols, 21 CFR 175.105, 176.170, 176.200, 176.210, 177.1010, and 178.3910; EU Regulation No 10/2011 FCM Substance No 209 / Ref No 68960 Octadecanol without Specific Migration Limit; Official USP-NF, Ph. Eur., BP, and JP Compendial Excipient)
Melting Point: 56.0 °C to 60.0 °C (132.8 °F to 140.0 °F; Pure 1-Octadecanol melting point: 59.4 °C to 59.8 °C; Solidification / Titer Point: 55.0 °C to 58.5 °C)
Boiling Point: 335.0 °C to 350.0 °C (635.0 °F to 662.0 °F) at 101.3 kPa atmospheric pressure; 210.0 °C (410.0 °F) at 2.0 kPa (15 mmHg) reduced pressure (Flash Point Closed Cup: ~185.0 °C to 195.0 °C)
Viscosity: Not Applicable as a waxy solid at 20 °C; in the molten liquid state, dynamic viscosity is approximately 9.5 to 11.5 mPa.s (cP) at 60 °C, 6.5 to 8.0 mPa.s at 75 °C, and 4.0 to 5.2 mPa.s at 100 °C (Kinematic Viscosity ~11.5 to 14.0 mm2/s at 60 °C)
Density: True solid density of 0.880 to 0.910 g/cm3 at 20 °C; molten liquid density of 0.805 to 0.815 g/cm3 (typically 0.812 g/cm3) at 60 °C (ISO 6883 / ASTM D1298); apparent loose bulk density of 460 to 550 kg/m3 (0.46 to 0.55 g/cm3) for pastilles and flakes

Most Frequently Encountered Synonyms:
Stearyl Alcohol
STEARYL ALCOHOL
1-Octadecanol
Octadecan-1-ol
n-Octadecanol
n-Octadecyl Alcohol
Octadecyl Alcohol
Octadecanol
C18 Linear Fatty Alcohol
C18 Primary Alcohol
Stearil Alkol
1-Oktadekanol
Oktadekanol
Oktadesil Alkol
Setil Stearil Alkol C18 Fraksiyonu
UNII-2KR89I4H1Y
FEMA 3215 (Octadecanol)
EU FCM No 209 (Ref No 68960)
CAS 112-92-5
EC 204-017-6

PRODUCT OVERVIEW, CHEMICAL IDENTITY AND OLEOCHEMICAL ARCHITECTURE

Stearyl Alcohol—registered globally under CAS Number 112-92-5 and European Community (EC / EINECS) Number 204-017-6, with FDA UNII Code 2KR89I4H1Y, EU Food Contact Material Substance Number 209 (Reference No. 68960), and Cosmetic INCI designation STEARYL ALCOHOL—is a saturated, straight-chain C18 aliphatic primary mono-alcohol carrying the molecular formula C18H38O and a molar mass of 270.49 g/mol. Recognized across international cosmetic science, dermatological compounding, surfactant synthesis, lubricant engineering, and plastics processing under its systematic IUPAC names 1-Octadecanol and Octadecan-1-ol, its common chemical names n-Octadecyl Alcohol, Octadecanol, and C18 Fatty Alcohol, and in Turkish chemical trade as Stearil Alkol or 1-Oktadekanol, this snow-white waxy solid is supplied by Ataman Kimya in free-flowing, dust-free pastilles, beads, and flakes.
At the molecular level, Stearyl Alcohol consists of a linear, fully saturated hydrocarbon chain of eighteen carbon atoms—CH3-(CH2)16-CH2-OH—terminated at the C1 position by a single primary hydroxyl functional group (-OH). This dual amphiphilic architecture gives Stearyl Alcohol its prized physical and interfacial behavior:

- The Hydrophobic C18 Alkyl Tail: The long, linear, unbranched octadecyl chain (chain length ~2.4 nm in the all-trans extended conformation) is strongly lipophilic and crystallizes via van der Waals dispersion forces into tightly packed orthorhombic and hexagonal lamellar lattices with a sharp melting point around 58 °C to 60 °C. Because the C18 chain contains zero carbon-carbon double bonds (Iodine Value <= 0.5 to 1.0 g I2/100 g), Stearyl Alcohol is completely resistant to atmospheric autoxidation, UV-induced yellowing, and rancid odor development during shelf storage.

- The Hydrophilic Primary Hydroxyl Headgroup (-CH2-OH): Although Stearyl Alcohol is insoluble in bulk water (< 0.001 mg/L at 25 °C) and cannot act as a standalone primary emulsifier on its own (having a low Required HLB of ~15.5 and an effective HLB of ~1.0 to 1.5), its terminal hydroxyl group participates in strong hydrogen-bonding networks with water molecules and polar surfactant headgroups at oil-water interfaces, enabling the formation of viscoelastic lamellar liquid-crystalline alpha-gels (L-beta / alpha-crystalline gel networks) that immobilize continuous water phases and prevent emulsion creaming or coalescence.
Formulators and chemical buyers must clearly distinguish pure Stearyl Alcohol (CAS 112-92-5) from three closely related fatty alcohols and fatty acids traded in the oleochemical industry:

Distinction from Cetyl Alcohol (1-Hexadecanol, C16H34O, CAS 36653-82-4, EC 253-149-0):
Cetyl Alcohol is the shorter C16 homologue (molecular weight 242.44 g/mol, Hydroxyl Value 225 to 235 mg KOH/g) with a lower melting point of 47 °C to 51 °C. Compared with Cetyl Alcohol, Stearyl Alcohol (C18, melting point 56 °C to 60 °C, Hydroxyl Value 200 to 215 mg KOH/g) possesses a melting point ~9 °C higher, imparting greater high-temperature viscosity stability in tropical climates, firmer stick rigidity in antiperspirant deodorant bars and lip balms, and a drier, richer velvety skin after-feel.

Distinction from Cetearyl Alcohol / Cetostearyl Alcohol (C16-C18 Mixed Fatty Alcohol, CAS 67762-27-0 / 8005-44-5):
Cetearyl Alcohol (INCI: CETEARYL ALCOHOL) is a co-crystallized blend of Cetyl Alcohol (C16) and Stearyl Alcohol (C18), typically traded in 50:50, 30:70, or 70:30 C16:C18 ratios with a melting point of 49 °C to 56 °C. By contrast, commercial pure Stearyl Alcohol supplied by Ataman Kimya contains >= 95.0 percent to 99.0 percent pure C18 1-Octadecanol (with <= 1.0 percent to 3.0 percent C16 hexadecanol), which is selected whenever formulators require maximum melting point, precise stoichiometric molecular weight for ethoxylation or methacrylate esterification, or specific compendial compliance under the USP-NF / Ph. Eur. Stearyl Alcohol monograph.

Distinction from Stearic Acid (Octadecanoic Acid, C18H36O2, CAS 57-11-4) and Oleyl Alcohol (cis-9-Octadecen-1-ol, C18H36O, CAS 143-28-2):
Stearic Acid carries a terminal carboxylic acid group (-COOH, Acid Value ~195 to 212 mg KOH/g) that reacts with alkalis (NaOH, KOH, TEA) to form anionic stearate soaps and is sensitive to pH below 6.5 and polyvalent cations (Ca2+, Mg2+, Al3+). By contrast, Stearyl Alcohol carries a neutral nonionic hydroxyl group (-CH2OH, Acid Value <= 0.1 to 0.5 mg KOH/g) that remains completely stable across pH 2.0 to 12.0 and is fully compatible with cationic quaternary ammonium hair conditioners, acidic alpha-hydroxy acids (AHAs), aluminum zirconium antiperspirant salts, and anionic/nonionic surfactants. Meanwhile, Oleyl Alcohol (C18:1) is an unsaturated liquid alcohol at room temperature (melting point 13 °C to 19 °C, Iodine Value 85 to 95 g I2/100 g), whereas Stearyl Alcohol is a fully saturated, oxidation-proof crystalline solid.

PHYSICAL AND CHEMICAL PROPERTIES AND QUANTITATIVE SPECIFICATIONS

Every commercial lot of Cosmetic, Pharmaceutical (USP-NF / Ph. Eur. / BP), and Industrial High-Purity Stearyl Alcohol (CAS 112-92-5, EC 204-017-6) supplied by Ataman Kimya is manufactured under strict ISO 9001 and GMP-aligned quality controls and tested against international AOCS, ASTM, ISO, and pharmacopeial analytical standards:

Carbon Chain-Length Distribution and Chemical Purity (Capillary Gas Chromatography per ASTM D1983 / ISO 6800 / USP-NF):
- Standard Cosmetic & Compendial 95% Grade (S95 / 1895 Grade):
  - C18 (1-Octadecanol): >= 95.0 percent w/w (typical batch value: 96.0 percent to 97.5 percent w/w; note that USP-NF and Ph. Eur. monographs specify >= 95.0 percent C18H38O).
  - C16 (1-Hexadecanol / Cetyl Alcohol): <= 3.0 percent to 4.0 percent w/w (typical: 1.5 percent to 2.8 percent w/w).
  - C20 (1-Eicosanol / Arachidyl Alcohol): <= 1.5 percent to 2.0 percent w/w (typical: 0.3 percent to 1.0 percent w/w).
  - C14 and Shorter (<= C14 Tetradecanol): <= 0.5 percent w/w.
- Ultra-High-Purity 98%+ Grade (1898 / 1899 Grade for Chemical Synthesis & Specialty Deodorant Sticks):
  - C18 (1-Octadecanol): >= 98.0 percent to 99.2 percent w/w.
  - C16 (1-Hexadecanol): <= 1.0 percent to 1.5 percent w/w.
  - C20 (1-Eicosanol): <= 0.5 percent to 1.0 percent w/w.
  - Total Linear Primary Alcohol Content: >= 99.0 percent to 99.7 percent w/w; Hydrocarbon Impurity Content: <= 0.3 percent to 0.5 percent w/w.

Quantitative Wet-Chemical Specifications (Hydroxyl, Acid, Saponification, Iodine, and Carbonyl Values):
- Hydroxyl Value (ISO 4326 / AOCS Cd 13-60 / ASTM E222 / USP <401>): 200.0 to 215.0 mg KOH/g (typical commercial batch range for 98% grade: 204.0 to 210.0 mg KOH/g; theoretical Hydroxyl Value of 100% pure C18H38O = 56,105.6 / 270.49 = 207.42 mg KOH/g; Ph. Eur. / USP-NF range: 195 to 220 mg KOH/g).
- Acid Value (Free Fatty Acid Content, ISO 660 / AOCS Te 1a-64 / USP <401>): <= 0.10 to 0.50 mg KOH/g (typical batch value: <= 0.05 to 0.10 mg KOH/g; USP-NF / Ph. Eur. limit: <= 1.0 to 2.0 mg KOH/g).
- Saponification Value / Ester Value (ISO 3657 / AOCS Tl 1a-64 / USP <401>): <= 0.5 to 1.0 mg KOH/g (typical batch value: 0.1 to 0.4 mg KOH/g; Ph. Eur. limit <= 2.0 mg KOH/g, confirming near-total conversion of methyl stearate esters during hydrogenation).
- Iodine Value (Residual Unsaturation, Wijs Method per ISO 3961 / AOCS Tg 1a-64 / USP <401>): <= 0.5 to 1.0 g I2/100 g (typical batch value: 0.05 to 0.30 g I2/100 g; USP-NF / Ph. Eur. limit: <= 2.0 g I2/100 g).
- Carbonyl Value (Aldehyde/Ketone Trace Content, ASTM E411): <= 50 to 100 mg/kg (ppm as C=O), ensuring zero odor drift during ethoxylation or cosmetic storage.
- Moisture / Water Content (Karl Fischer Titration, ISO 8534 / ASTM E203): <= 0.10 percent to 0.20 percent w/w (typical batch value: 0.03 percent to 0.08 percent w/w).

Physical, Thermal, Optical, and Rheological Constants:
- Visual Appearance and Odor at 20 °C: Snow-white, hard, waxy pastilles (hemispherical beads, 2 to 5 mm diameter), flakes, or microbeads with a faint, clean, pleasant characteristic waxy odor; melts to a crystal-clear, colorless transparent liquid at 60 °C.
- Melt Color on Pt-Co (APHA / Hazen) Scale at 65 °C (ASTM D1209 / ISO 6271): <= 10 to 20 APHA units (typical batch value: 5 to 10 APHA, water-white).
- Melting Point / Capillary Slip Melting Range (ISO 6321 / AOCS Cc 1-25 / USP <741>): 56.0 °C to 60.0 °C (132.8 °F to 140.0 °F; USP-NF / Ph. Eur. specification: 55.0 °C to 60.0 °C; pure 1-Octadecanol crystal melts at 59.4 °C to 59.8 °C).
- Solidification Point / Congealing Titer (ASTM D1493 / AOCS Cc 12-59): 55.0 °C to 58.5 °C (131.0 °F to 137.3 °F; typically 56.5 °C to 58.0 °C for >= 98% C18 grade).
- Enthalpy of Fusion / Latent Heat of Melting (DSC): Approximately 240 to 255 J/g (65 to 69 kJ/mol, making Stearyl Alcohol an exceptionally high-enthalpy organic Phase Change Material, PCM).
- Boiling Point and Distillation Range: 335.0 °C to 350.0 °C at 101.3 kPa (760 mmHg) with slight thermal decomposition; 210.0 °C at 2.0 kPa (15 mmHg); 170.0 °C at 0.27 kPa (2 mmHg).

- Density / Specific Gravity:
  - Solid Crystal Density at 20 °C: 0.880 to 0.910 g/cm3 (880 to 910 kg/m3).
  - Molten Liquid Density at 60 °C (ISO 6883 / ASTM D1298): 0.805 to 0.815 g/cm3 (typically 0.812 g/cm3 at 60 °C and 0.798 g/cm3 at 80 °C).
  - Apparent Bulk Density (Pastilles / Flakes): 460 to 550 kg/m3 (0.46 to 0.55 g/cm3).
- Molten Dynamic and Kinematic Viscosity: Dynamic viscosity of 9.5 to 11.5 mPa.s (cP) at 60 °C, 6.8 mPa.s at 75 °C, and 4.4 mPa.s at 100 °C; Kinematic viscosity of ~12.2 mm2/s (cSt) at 60 °C.
- Refractive Index in Molten State (nD60 / nD70, ISO 6320): 1.4345 to 1.4365 at 60 °C (specifically ~1.4356 at 60 °C and ~1.4315 at 70 °C).
- Flash Point, Auto-Ignition, and Vapor Pressure:
  - Flash Point (Pensky-Martens Closed Cup, ASTM D93 / ISO 2719): ~185.0 °C to 195.0 °C (365 °F to 383 °F); Cleveland Open Cup (ASTM D92): ~195.0 °C to 205.0 °C.
  - Auto-Ignition Temperature (DIN 51794): Approximately 245.0 °C to 260.0 °C (473 °F to 500 °F).
  - Vapor Pressure: < 0.001 Pa (< 1.0 x 10^-5 hPa) at 20 °C; ~0.13 Pa at 60 °C; ~133 Pa (1.0 mmHg) at 150 °C.
- Solubility and Partition Coefficient Profile:
  - Water Solubility: Practically insoluble in water (< 0.001 mg/L at 25 °C).
  - Organic Solvent Solubility: Freely soluble in warm ethanol (96%), isopropyl alcohol, diethyl ether, acetone, chloroform, methylene chloride, benzene, toluene, hexane, mineral oils, vegetable triglyceride oils, silicone fluids (cyclomethicone, dimethicone at elevated temperature), and fatty acid esters (isopropyl myristate, caprylic/capric triglyceride).
  - Octanol-Water Partition Coefficient (Log Kow, OECD 117 / 123): 7.19 to 7.72 (confirming strong lipophilicity).

POLYMORPHIC CRYSTALLIZATION AND LAMELLAR LIQUID-CRYSTALLINE GEL-NETWORK PHYSICS

Understanding why Stearyl Alcohol (1-Octadecanol, CAS 112-92-5) acts as a premier rheological structurant in cosmetic creams, hair conditioners, and anhydrous deodorant sticks requires examining both its solid-state crystal polymorphism and its hydrated lamellar gel-network (LGN) phase behavior:

Solid-State Polymorphism of Pure Stearyl Alcohol (Alpha, Beta, and Gamma Phases):
When molten Stearyl Alcohol cools below its solidification point (~58.0 °C), the linear C18H37OH chains first nucleate into a metastable, waxy hexagonal rotator phase known as the alpha-polymorph (alpha-form, existing between ~54.5 °C and 58.5 °C), in which the hydrocarbon chains are packed hexagonally perpendicular to the lamellar basal plane and retain rotational freedom around their long axes while their terminal -OH groups form hydrogen-bonded bilayers. Upon further cooling below ~54 °C, pure unblended 1-Octadecanol undergoes a solid-state polymorphic transition into more densely packed, brittle monoclinic gamma (gamma) or orthorhombic beta (beta) crystal polymorphs with tilted hydrocarbon chains.
Crucially, in anhydrous stick formulations—such as Aluminum Zirconium Tetrachlorohydrex GLY antiperspirant solid sticks—Stearyl Alcohol (dosed at 14 percent to 22 percent w/w) is combined with 2 percent to 5 percent w/w of a co-structurant (such as hydrogenated castor oil, glyceryl stearate, or PEG-8 distearate) to control crystal size during cooling at 50 °C to 55 °C, creating an interlocking microcrystalline network of sub-10-micron plate crystals that immobilizes volatile silicone or hydrocarbon carrier fluids with high mechanical break-strength and zero syneresis ("stick sweating").

Hydrated Lamellar Gel Network (LGN) Formation in O/W Emulsions and Hair Conditioners:
When Stearyl Alcohol is melted into the oil phase of an oil-in-water (O/W) emulsion or cationic hair conditioner at 70 °C to 80 °C alongside an ionic or nonionic primary surfactant (such as Behentrimonium Chloride, Cetrimonium Chloride, Stearamidopropyl Dimethylamine, Ceteareth-20, Sodium Cetearyl Sulfate, or Potassium Cetyl Phosphate) at a typical molar ratio of 3:1 to 6:1 fatty alcohol to surfactant, a remarkable self-assembly process occurs upon cooling below the chain-melting transition temperature (Tm ~55 °C to 58 °C):
- Above Tm (70 °C to 80 °C): Stearyl Alcohol and the surfactant co-assemble into fluid lamellar liquid-crystalline bilayers (L-alpha phase).
- Below Tm (< 50 °C): The C18 hydrocarbon tails freeze into a rigid yet hydrated hexagonal alpha-crystalline gel bilayer (the L-beta or alpha-gel state), where the terminal -OH groups of Stearyl Alcohol hydrogen-bond with the polar headgroups of the surfactant and orient toward interlamellar water layers (10 to 30 nm thick).
- Macroscopic Rheological Benefit: This hydrated lamellar gel network traps bulk interlamellar water and surrounds dispersed oil droplets with a mechanical viscoelastic barrier, building rich, shear-thinning (pseudoplastic) cream body (20,000 to 150,000 mPa.s at 25 °C) that spreads effortlessly under finger shear without stringiness, tackiness, or soapy whitening ("soaping").

INDUSTRIAL MANUFACTURING PROCESSES: OLEOCHEMICAL HYDROGENATION AND ZIEGLER SYNTHESIS

Commercial production of high-purity Stearyl Alcohol (CAS 112-92-5) is performed via two distinct industrial routes—the renewable Natural Oleochemical Route (accounting for > 80 percent of global cosmetic and pharmaceutical volume) and the Synthetic Petrochemical Ziegler Route:

Natural Oleochemical Route (Lurgi / Davy Process via Methyl Ester Hydrogenation and Fractional Distillation):
- Step 1 — Triglyceride Transesterification (Methanolysis) or Fat Splitting: Sustainably sourced vegetable oils rich in C16–C18 chains—specifically Refined Palm Stearin, Palm Kernel Oil, Soybean Oil (fully hydrogenated), or Rapeseed Oil—are reacted with methanol at 65 °C to 80 °C in the presence of an alkaline sodium methoxide catalyst to generate Crude Fatty Acid Methyl Esters (FAME) and glycerol (or alternatively, split with high-pressure water at 250 °C and 50 bar into free fatty acids, which are hydrogenated to C18 stearic acid and then esterified with methanol).
- Step 2 — Fractional Vacuum Distillation of Methyl Stearate: The mixed C16–C18 methyl esters (or free fatty acids) are fractionated in high-efficiency structured-packing vacuum distillation columns (operating at 2 to 10 mbar absolute pressure and 180 °C to 220 °C) to isolate a narrow C18 Methyl Stearate cut (Methyl Octadecanoate, purity >= 96 percent to 99 percent).
- Step 3 — High-Pressure Catalytic Hydrogenolysis (R-COOCH3 + 2 H2 --> R-CH2OH + CH3OH): The purified Methyl Stearate is fed continuously with excess high-purity hydrogen gas (H2) through a fixed-bed tubular reactor or slurry-phase reactor packed with a heterogeneous Copper Chromite (CuO.CuCr2O4) or chromium-free Copper-Zinc-Aluminum (Cu-Zn-Al) catalyst at 200 °C to 250 °C and 200 to 300 bar (20 to 30 MPa) pressure. Under these conditions, both the ester carbonyl bond and any trace olefinic double bonds are selectively reduced, converting Methyl Stearate quantitatively into crude Stearyl Alcohol (1-Octadecanol) and recycling liberated methanol back to the transesterification unit.
- Step 4 — Final Vacuum Rectification, Deodorization, and Steel-Belt Pastillation: Crude 1-Octadecanol is polished in a final high-vacuum distillation column to strip trace C18 octadecane hydrocarbons (< 0.3 percent) and unreacted esters (Saponification Value <= 0.5 mg KOH/g), stripped with nitrogen/steam to remove trace carbonyl odors, and solidified on a chilled stainless-steel Rotoform belt into uniform, dust-free snow-white Stearyl Alcohol pastilles or flakes.

Synthetic Petrochemical Route (Ziegler Ethylene Oligomerization Process):
In the Ziegler Alfol process, triethylaluminum (Al(C2H5)3) reacts with dry ethylene gas at 110 °C to 130 °C and 100 bar to grow even-numbered linear trialkylaluminum chains, which are oxidized with dry air at 40 °C to 60 °C into aluminum alkoxides and hydrolyzed with dilute sulfuric acid or water to yield a Poisson distribution of perfectly linear even-carbon primary alcohols (C2 to C22+). Fractional vacuum distillation of the C18 cut yields synthetic 1-Octadecanol (such as Alfol 18 / Nacol 18-98) with > 98.5 percent C18 linearity and zero branched isomers, chemically identical to botanical Stearyl Alcohol except for radiocarbon (14C) bio-based signature.

COMPREHENSIVE APPLICATIONS AND FORMULATION ENGINEERING

Owing to its high C18 chain purity (>= 95 percent to 98 percent), sharp melting point (56 °C to 60 °C), chemical inertness, and global pharmacopeial status, Stearyl Alcohol supplied by Ataman Kimya is utilized across eight major industrial sectors:

Hair Care Formulations (Rinse-Off Conditioners, Deep Hair Masks, Cream Dyes, and Leave-In Treatments):
Hair conditioning products represent one of the largest cosmetic applications of Stearyl Alcohol:
- Synergistic Cationic Lamellar Gel Structurant (2.0% to 7.0% w/w): In rinse-off hair conditioners, detangling balms, and hair repair masks, Stearyl Alcohol is formulated at 2.5 percent to 6.0 percent w/w (often combined with Cetyl Alcohol at a 70:30 or 60:40 C18:C16 ratio) alongside 0.8 percent to 2.5 percent w/w of a cationic conditioning surfactant such as Behentrimonium Chloride (BTAC), Behentrimonium Methosulfate (BTMS), Cetrimonium Chloride (CTAC), or Stearamidopropyl Dimethylamine. Upon cooling, Stearyl Alcohol builds a rich lamellar alpha-gel phase that deposits a microscopic hydrophobic C18 lipid monolayer along damaged, negatively charged keratin cuticle scales—reducing wet and dry combing force by 60 percent to 85 percent, smoothing split ends, neutralizing static flyaway, and providing heavier, silkier moisture lock than Cetyl Alcohol alone.
- Oxidative Hair Colorant Creams: Dosed at 4.0 percent to 10.0 percent w/w with Steareth-2 / Steareth-20 or Ceteareth-25 in alkaline ammonia/ethanolamine and hydrogen peroxide hair dye bases to build non-drip cream rheology that remains stable at pH 10.0 to 11.0.

Skin Care, Dermo-Cosmetics, Sunscreens, and Body Butters (INCI: STEARYL ALCOHOL):
- O/W and W/O Emulsion Viscosity Builder and Co-Emulsifier (1.0% to 6.0% w/w): In moisturizing facial creams, hand lotions, barrier repair ointments, baby creams, and SPF sunscreens, Stearyl Alcohol thickens the continuous phase via liquid-crystalline lamellar networks while imparting a soft, powdery, velvety matte after-feel without the waxy drag of beeswax or the greasiness of petrolatum.
- Reduce "Soaping" (Whitening on Rub-Out): Replacing part of Cetyl Alcohol or Stearic Acid with high-purity Stearyl Alcohol and 0.5 percent to 1.5 percent dimethicone reduces the white micro-foam ("soaping effect") that occurs when O/W lotions are rubbed onto the skin.

Antiperspirant and Deodorant Solid Sticks and Soft-Solid Gels (12.0% to 24.0% w/w):
Stearyl Alcohol (specifically high-purity >= 98% C18 grade) is the primary structural wax backbone of anhydrous suspension Antiperspirant Solid Sticks ("invisible dry sticks"):
- Matrix Gelling of Cyclopentasiloxane / Isohexadecane / C12-15 Alkyl Benzoate: Melted at 70 °C to 78 °C at a dosage of 14.0 percent to 22.0 percent w/w together with 2.5 percent to 4.5 percent w/w Hydrogenated Castor Oil (MP 85 °C) and 20 percent to 25 percent w/w active Aluminum Zirconium Tetrachlorohydrex GLY powder in volatile silicone or emollient esters, Stearyl Alcohol crystallizes at 50 °C to 55 °C into a firm, self-supporting stick that glides smoothly onto underarm skin at 35 °C–37 °C without crumbling, cracking, or sweating oil during summer shipping.

Pharmaceutical Compendial Excipient: Topical Ointments and Sustained-Release Oral Tablets (USP-NF / Ph. Eur. / BP / JP):
- Dermatological Ointment & Cream Bases (3.0% to 35.0% w/w): Official component of USP Hydrophilic Ointment (25% w/w Stearyl Alcohol + 25% White Petrolatum + 12% Propylene Glycol + 1% SLS + 37% Water) and USP Cetyl Esters Wax / Emulsifying Ointment bases. Stearyl Alcohol increases the water-holding capacity (water number) of white petrolatum and paraffin bases, allowing incorporation of aqueous active pharmaceutical ingredients (APIs) such as corticosteroids, antifungals, and antibiotics into washable water-in-oil and oil-in-water dermatological creams.
- Oral Sustained-Release Hydrophobic Matrix Tablets (10.0% to 35.0% w/w): Used in melt granulation, hot-melt extrusion (HME), and direct compression to form inert hydrophobic wax matrices around highly water-soluble drugs (such as metoprolol, tramadol, theophylline, or potassium chloride), retarding drug dissolution into zero-order or Higuchi diffusion profiles over 8 to 24 hours independent of gastrointestinal pH.

Chemical Intermediate for Ethoxylated, Sulfated, and Esterified Derivatives:
More than 55 percent of global industrial Stearyl Alcohol production is consumed as a reactive primary alcohol intermediate (R-OH):
- Ethoxylated Nonionic Surfactants (Steareth-n, CAS 9005-00-9): Reacting Stearyl Alcohol with ethylene oxide (EO) in the presence of KOH catalyst produces polyoxyethylene stearyl ethers spanning low-HLB W/O emulsifiers (Steareth-2, HLB 4.9) to high-HLB O/W solubilizers and emulsifiers (Steareth-20, HLB 15.3; Steareth-21, HLB 15.5; Steareth-100, HLB 18.8).
- Stearyl Methacrylate (SMA, CAS 32360-05-7) & Stearyl Acrylate: Esterification or transesterification of Stearyl Alcohol with methacrylic acid or methyl methacrylate yields Stearyl Methacrylate monomer, which is polymerized into Poly(Alkyl Methacrylate) (PAMA) comb-polymers used globally as Pour Point Depressants (PPDs) and Viscosity Index Improvers (VIIs) in automotive crankcase engine oils, hydraulic fluids, and crude-oil wax crystal modifiers.
- Sodium Stearyl Sulfate, Stearyl Chloride, Stearyl Amine, and Quats: Sulfation with SO3 yields Sodium Stearyl Sulfate; chlorination or amination produces 1-Chlorooctadecane and Stearyl Dimethylamine, the direct precursors for Behentrimonium/Steartrimonium Chloride and Benzalkonium/Stearalkonium Chloride cationic surfactants.
- Fatty Acid Esters & Dialkyl Thiodipropionates: Esterified with stearic, erucic, or octanoic acid to yield Stearyl Stearate, Stearyl Erucate, and Stearyl Heptanoate cosmetic emollients and polymer lubricants, or reacted to produce Distearyl Thiodipropionate (DSTDP, CAS 693-36-7) secondary antioxidant for polyolefins (PP/PE).

Polymer Processing Lubricants, Textile Softeners, Paper Defoamers, and Evaporation Suppressants:
- PVC and Engineering Thermoplastic Internal/External Lubricant (0.3 to 1.5 phr): In rigid and flexible PVC extrusion, calendering, and injection molding, Stearyl Alcohol reduces inter-particle friction during fusion, lowers melt viscosity, and enhances surface gloss in clear PVC sheets and bottles without clouding.
- Paper Coating Lubricant & Pulp Mill Defoamer: Dispersed at 10 percent to 25 percent solids in aqueous emulsions as a high-efficiency drainage aid and brown-stock / paper-coating defoamer (cleared under FDA 21 CFR 176.200 / 176.210).
- Water Reservoir Monolayer Evaporation Suppressant & Phase Change Material (PCM): Because 1-Octadecanol spreads spontaneously on water surfaces to form a condensed monomolecular film (Langmuir monolayer, molecular cross-sectional area ~0.20 nm2) that resists water-vapor transport, it is applied onto agricultural reservoirs and lakes in arid regions to reduce water evaporation by 25 percent to 40 percent, and is microencapsulated as a high-latent-heat (245 J/g) Phase Change Material for thermal energy storage at 56 °C–59 °C.

Practical Guide Formulation Frameworks Featuring Stearyl Alcohol:
- Guide Formulation 1 (Salon-Grade Deep Moisturizing & Detangling Hair Conditioner): Deionized Water 86.2 percent w/w, Stearyl Alcohol (CAS 112-92-5, >= 96% C18) 4.5 percent w/w, Cetyl Alcohol (C16) 1.5 percent w/w, Behentrimonium Chloride (80% active) 2.5 percent w/w, Amodimethicone / Dimethicone Blend 2.0 percent w/w, Glycerin 2.0 percent w/w, Panthenol (Pro-Vitamin B5) 0.5 percent w/w, Citric Acid (to pH 4.2–4.8) 0.1 percent w/w, and Phenoxyethanol / Ethylhexylglycerin Preservative + Fragrance 0.7 percent w/w.
- Guide Formulation 2 (Anhydrous Invisible Solid Antiperspirant Deodorant Stick): Cyclopentasiloxane (or Isohexadecane / C12-15 Alkyl Benzoate) 49.0 percent w/w, Active Aluminum Zirconium Tetrachlorohydrex GLY (Micronized Powder) 24.0 percent w/w, Stearyl Alcohol (98% High-Purity Grade, MP 58 °C) 18.0 percent w/w, Hydrogenated Castor Oil (Co-Gellant, MP 85 °C) 3.5 percent w/w, PPG-14 Butyl Ether (Emollient Anti-Whitening Agent) 3.5 percent w/w, Talc or Corn Starch 1.0 percent w/w, and Fragrance 1.0 percent w/w.
- Guide Formulation 3 (USP Hydrophilic Dermatological Cream Base): White Petrolatum 25.0 percent w/w, Stearyl Alcohol (USP-NF Grade) 25.0 percent w/w, Propylene Glycol 12.0 percent w/w, Sodium Lauryl Sulfate (or Ceteareth-20) 1.0 percent w/w, Purified Water 36.8 percent w/w, and Antimicrobial Preservative 0.2 percent w/w.

TECHNICAL COMPARISON OF STEARYL ALCOHOL WITH CETYL, CETEARYL AND BEHENYL ALCOHOLS

Selecting the optimal linear fatty alcohol requires comparing Stearyl Alcohol (C18) against its neighboring homologous fatty alcohols across chain length, melting point, Hydroxyl Value, and emulsion sensory profile:

Stearyl Alcohol (C18, CAS 112-92-5) vs. Cetyl Alcohol (C16, CAS 36653-82-4):
Cetyl Alcohol (1-Hexadecanol, MW 242.44 g/mol) has a lower melting point (47 °C to 51 °C) and higher Hydroxyl Value (225 to 235 mg KOH/g). Cetyl Alcohol forms softer, lighter lotions with faster initial rub-in, but emulsions built solely with Cetyl Alcohol can thin out or separate when stored at elevated summer temperatures (> 40 °C to 45 °C). Stearyl Alcohol (C18, MW 270.49 g/mol, MP 56 °C to 60 °C, Hydroxyl Value 200 to 215 mg KOH/g) builds higher high-temperature yield stress, superior stick hardness for deodorant bars, and a more protective, velvety hydrophobic barrier on hair and skin.

Stearyl Alcohol (C18, CAS 112-92-5) vs. Cetearyl Alcohol (C16/C18 Blend, CAS 67762-27-0):
Cetearyl Alcohol (Cetostearyl Alcohol, typically 50:50 or 30:70 C16:C18) exploits mixed-chain packing asymmetry to inhibit beta-crystal embrittlement over time in general-purpose creams (MP 49 °C to 56 °C). However, whenever a formulator needs maximum melting point (58 °C) for anhydrous deodorant sticks, exact C18:C16 ratio customization in hair conditioners, or a narrow single-homologue feedstock for chemical synthesis (ethoxylation to Steareth-n or esterification to Stearyl Methacrylate), pure Stearyl Alcohol (>= 95% to 98% C18) is mandatory.

Stearyl Alcohol (C18, CAS 112-92-5) vs. Behenyl Alcohol (C22, 1-Docosanol, CAS 661-19-8):
Behenyl Alcohol (C22H46O, MW 326.60 g/mol, MP 68 °C to 73 °C) is four carbons longer and has a higher melting point, but costs 2.5 to 4 times more per kilogram and requires higher processing temperatures (> 80 °C). Stearyl Alcohol delivers 90 percent of the structural rigidity and cushion of Behenyl Alcohol at a fraction of the cost and melts cleanly at 65 °C–70 °C.

PACKAGING, STORAGE AND HANDLING GUIDELINES

To preserve the snow-white color (melt APHA <= 10 to 20), free-flowing pastille or flake morphology, low moisture content, and neutral odor profile of Stearyl Alcohol (1-Octadecanol, Octadecan-1-ol, CAS 112-92-5), warehouse managers and plant operators should follow the storage and handling protocols established by Ataman Kimya:
Commercial Packaging Configurations Supplied by Ataman Kimya:
- 20 kg and 25 kg Net Multi-Wall Bags or Polyethylene Bags: Heavy-duty woven polypropylene or multi-wall kraft paper bags fitted with a food/cosmetic-grade low-density polyethylene (LDPE) moisture-barrier inner liner (or heavy-gauge form-fill-seal PE bags), containing dust-free Stearyl Alcohol pastilles or flakes (standard palletization: 40 x 25 kg bags = 1,000 kg net on shrink-wrapped ISPM-15 fumigated wooden or plastic pallets).
- 500 kg to 1,000 kg Net Flexible Intermediate Bulk Containers (FIBCs / Big Bags): Lined polypropylene jumbo bags with top filling spout and bottom discharge spout for high-volume surfactant, lubricant, and cosmetic plants.
- 20,000 kg to 24,000 kg Net Heated Bulk Liquid Transport: Insulated 316L stainless-steel road tankers and ISO tank containers equipped with low-pressure steam or hot-water heating coils for delivering molten Stearyl Alcohol at 68 °C to 78 °C under a dry nitrogen blanket.

Storage Conditions and Thermal / Quality Protection:

Cool, Dry Indoor Warehouse Storage (< 35 °C / 95 °F): Although Stearyl Alcohol has a relatively high melting point (56 °C to 60 °C / 133 °F to 140 °F)—making it significantly more resistant to summer caking than Cetyl Alcohol (MP 49 °C)—storing bags or pallets of Stearyl Alcohol in unventilated summer shipping containers (> 45 °C), under direct sunlight, or adjacent to steam lines can cause surface softening and pressure sintering ("blocking" or lumping) in the bottom bags of stacked pallets. Store Stearyl Alcohol in a cool, dry, well-ventilated indoor warehouse maintained below 30 °C to 35 °C (50 °F to 95 °F) and relative humidity below 70 percent, away from direct UV sunlight, heaters, and strong odorous chemicals. Do not stack pallets more than two high.

 Molten Bulk Tank Storage Protocol (65 °C to 75 °C under Nitrogen): When storing Stearyl Alcohol as a molten liquid in bulk factory tanks, construct tanks and transfer piping from 304 or 316L stainless steel (or aluminum); never use unlined carbon steel, copper, or brass, as trace iron and copper ions catalyze oxidative yellowing (APHA color drift). Maintain molten tank temperature strictly between 65 °C and 75 °C (5 °C to 15 °C above the solidification point) using warm-water or low-pressure steam (< 2.5 bar) coils, and blanket the tank headspace with dry Nitrogen gas (N2) to prevent oxygen contact and carbonyl/acid value increase.

 Shelf Life: When stored unopened in original sealed bags in a cool, dry warehouse (< 30 °C) away from sunlight and moisture, solid Stearyl Alcohol pastilles and flakes have a certified shelf life of 24 to 36 months (2 to 3 years) from the date of manufacture.

FIRST AID MEASURES, TOXICOLOGY AND SAFETY INFORMATION

Stearyl Alcohol (1-Octadecanol, Octadecan-1-ol, CAS 112-92-5, EC 204-017-6) is a non-toxic, biodegradable, dermatologically gentle long-chain fatty alcohol that is NOT classified as a hazardous substance or hazardous mixture under European Union Regulation (EC) No 1272/2008 (CLP) or the UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS). It carries no GHS hazard pictograms, no signal word, and no hazard statements.

Quantitative Toxicological and Ecotoxicological Profile:
- Acute Oral Toxicity (OECD Test Guideline 401): LD50 (Rat, oral) > 5,000 mg/kg body weight (experimental values > 8,000 to 20,000 mg/kg bw, demonstrating practically non-toxic oral safety).
- Acute Dermal Toxicity (OECD Test Guideline 402): LD50 (Rabbit, dermal) > 3,000 to 5,000 mg/kg body weight.
- Skin Corrosion / Irritation (OECD Test Guideline 404): Non-irritating to intact rabbit and human skin (Primary Irritation Index PII = 0.0 to 0.2; widely used at up to 25%+ in dermatological creams and deodorant sticks).

- Serious Eye Damage / Eye Irritation (OECD Test Guideline 405): Non-irritating or causes only mild, fully reversible mechanical conjunctival redness within 24–48 hours; does not cause corneal opacity.
- Skin Sensitization (OECD Test Guideline 406): Non-sensitizing in Guinea Pig Maximization Test (GPMT), Buehler assay, and Human Repeated Insult Patch Tests (HRIPT).
- Genotoxicity, Carcinogenicity, and Reproductive Toxicity: Negative in bacterial reverse mutation (Ames OECD 471), mammalian cell gene mutation (OECD 476), and micronucleus assays; NOAEL for repeated-dose oral toxicity (OECD 422) is >= 1,000 mg/kg bw/day; not listed as a carcinogen by IARC, NTP, OSHA, or EU CLP; evaluated as Safe as Used in cosmetics by the US Cosmetic Ingredient Review (CIR) Expert Panel.
First Aid Measures for Industrial and Laboratory Exposure:

- Skin Contact: Solid Stearyl Alcohol pastilles at room temperature are non-irritating to skin; wash off with soap and water. If accidental splash contact occurs with hot molten Stearyl Alcohol (> 60 °C to 90 °C), cool the affected skin immediately under cold running tap water for at least 10 to 15 minutes to dissipate thermal energy. Do not forcefully peel solidified wax off burned or blistered skin; seek medical attention if thermal burns develop.
- Eye Contact: If solid dust or small beads of Stearyl Alcohol enter the eye, do not rub; flush gently with lukewarm running water or isotonic saline eyewash solution for 10 to 15 minutes while holding eyelids open. If hot molten Stearyl Alcohol splashes into the eye, flush immediately with cool-to-lukewarm water for 15 minutes and seek immediate ophthalmological evaluation.
- Inhalation: At ambient temperature, Stearyl Alcohol is non-volatile (vapor pressure < 0.001 Pa). Avoid breathing fine dust if handling attrition powder, or hot oil mists/vapors if heated above 120 °C to 180 °C. Move any affected person to fresh air and seek medical attention if respiratory irritation occurs.

- Ingestion: Rinse mouth thoroughly with water and drink 1 to 2 glasses of water. Do not induce vomiting. Seek medical advice if large quantities of Stearyl Alcohol are swallowed.
Fire-Fighting Measures and Spill Response Procedures:
- Suitable Extinguishing Media: Stearyl Alcohol has a high Closed-Cup Flash Point (~185 °C to 195 °C). In the event of a fire involving molten Stearyl Alcohol, extinguish using alcohol-resistant foam, dry chemical powder (ABC/BC), carbon dioxide (CO2), or fine water mist/fog. NEVER direct a high-pressure solid water jet into a tank of burning molten Stearyl Alcohol, as water (density 1.00 g/cm3) sinks beneath the lighter molten alcohol (density ~0.81 g/cm3) and flashes violently into steam, ejecting burning liquid!
- Spill Cleanup: Sweep or vacuum spilled solid Stearyl Alcohol pastilles or flakes mechanically into clean, dry containers for reuse or disposal (avoid generating airborne dust clouds). If molten Stearyl Alcohol spills onto factory floors, allow it to cool and solidify below 55 °C, scrape up the solid wax with non-sparking tools, and wash the residual floor surface with hot water and alkaline detergent to eliminate slip hazards.

REGULATORY STATUS, COMPLIANCE AND INTERNATIONAL CLASSIFICATIONS

Stearyl Alcohol (CAS 112-92-5, EC 204-017-6) holds comprehensive global regulatory clearances across pharmaceuticals, cosmetics, food-contact materials, and industrial chemical inventories:

 Pharmaceutical Compendial Monographs (USP-NF, Ph. Eur., BP, JP):
Official monograph excipient in the United States Pharmacopeia–National Formulary (USP-NF: Stearyl Alcohol, requiring >= 95.0 percent C18H38O, melting range 55 °C to 60 °C, Acid Value <= 2.0, Iodine Value <= 2.0, Hydroxyl Value 195 to 220), European Pharmacopoeia (Ph. Eur. / British Pharmacopoeia BP: Alcohol stearylicus / Stearyl Alcohol, requiring >= 95.0 percent C18H38O, melting point 57 °C to 60 °C, Acid Value <= 1.0, Iodine Value <= 2.0, Hydroxyl Value 197 to 217, Saponification Value <= 2.0), and Japanese Pharmacopoeia (JP: Stearyl Alcohol). Listed on the US FDA Inactive Ingredient Database (IID) for topical, transdermal, vaginal, rectal, and oral sustained-release dosage forms.

 Global Cosmetics Regulations (INCI: STEARYL ALCOHOL):
Approved worldwide without concentration limits under European Union Cosmetics Regulation (EC) No 1223/2009 (CosIng Official Functions: Emollient, Emulsion Stabilising, Foam Boosting, Masking, Opacifying, Refatting, Surfactant, Viscosity Controlling), ASEAN Cosmetic Directive, Health Canada, Japan MHLW, and China NMPA IECIC.

 Food & Food-Contact Clearances (EU Regulation 10/2011 & US FDA 21 CFR):
- European Union Plastics Food Contact Regulation (EU) No 10/2011: Listed on the Union List under FCM Substance No. 209 (Reference No. 68960, CAS 112-92-5, "octadecanol") as an authorized additive or polymer production aid with NO Specific Migration Limit restriction (SML = Not Specified / 60 mg/kg overall migration limit).
- US FDA Title 21 CFR Clearances: Cleared as a direct multipurpose food additive and synthetic fatty alcohol under 21 CFR 172.864, a flavoring substance (FEMA No. 3215 / 21 CFR 172.515), and an indirect food-contact additive under 21 CFR 175.105 (Adhesives), 176.170 / 176.200 / 176.210 (Paper and paperboard coatings and defoamers), 177.1010 (Acrylic plastics), and 178.3910 (Surface lubricants for metallic food articles).

 Chemical Inventories, REACH, Biodegradability, and Transport Classification:
- Global Chemical Inventories: Listed on US TSCA (Active, CAS 112-92-5), EU EINECS (204-017-6, full EU REACH Registration completed), Canada DSL, Australia AIIC, China IECSC, Japan ENCS (2-217), South Korea KECI (KE-26333), Philippines PICCS, and New Zealand NZIoC.
- Biodegradability & Sustainability: Readily biodegradable in aerobic water and soil under OECD Test Guideline 301B and 301D (> 80 percent to 95 percent biodegradation within 28 days). Vegetable-derived grades supplied by Ataman Kimya are 100 percent bio-based (ASTM D6866), GMO-free, Vegan, Halal, and Kosher certified, with RSPO Mass Balance (MB) or Segregated (SG) certification available upon request.
- International Transport Codes (ADR / RID / IMDG / IATA): Not Regulated as Dangerous Goods across road, rail, sea, or air transport (UN Number: Not Regulated; Hazard Class: None; Packing Group: None; Marine Pollutant: No).

FREQUENTLY ASKED QUESTIONS (FAQ)

 What is Stearyl Alcohol and how is it chemically manufactured?
Stearyl Alcohol (IUPAC name: 1-Octadecanol or Octadecan-1-ol, CAS 112-92-5, EC 204-017-6, molecular formula C18H38O, MW 270.49 g/mol) is a saturated, straight-chain C18 primary fatty alcohol supplied as snow-white waxy pastilles or flakes. Commercially, oleochemical Stearyl Alcohol is manufactured by transesterifying sustainable vegetable oils (such as palm stearin or palm kernel oil) with methanol, fractionally distilling the C18 methyl stearate ester, and subjecting it to high-pressure catalytic hydrogenation (200 °C to 250 °C, 200 to 300 bar H2 over a copper catalyst) to reduce the ester group into a primary alcohol (-CH2OH), followed by vacuum rectification to >= 95 percent to 98 percent+ C18 purity.

 Is Stearyl Alcohol drying or irritating to sensitive skin like ethanol or isopropyl alcohol?
No, Stearyl Alcohol is a non-volatile, oil-soluble long-chain fatty alcohol (C18H38O) and behaves completely differently from short-chain volatile solvents like ethanol (C2H5OH) or isopropyl alcohol (C3H7OH). Whereas short-chain alcohols strip epidermal lipids and dehydrate skin, Stearyl Alcohol is a soothing, non-irritating, non-sensitizing lipid emollient and barrier structurant that locks moisture into the stratum corneum and imparts a soft, velvety skin feel—making it safe even for sensitive, dry, and infant skin formulations.

 What is the difference between Stearyl Alcohol (CAS 112-92-5), Cetyl Alcohol (CAS 36653-82-4), and Cetearyl Alcohol (CAS 67762-27-0)?
Cetyl Alcohol (1-Hexadecanol, C16H34O) is a 16-carbon linear fatty alcohol with a lower melting point of 47 °C to 51 °C and a Hydroxyl Value of 225 to 235 mg KOH/g. Stearyl Alcohol (1-Octadecanol, C18H38O) is an 18-carbon linear fatty alcohol with a higher melting point of 56 °C to 60 °C and a Hydroxyl Value of 200 to 215 mg KOH/g, providing firmer stick rigidity, higher thermal viscosity stability, and richer conditioning slip. Cetearyl Alcohol (Cetostearyl Alcohol) is a physical blend of Cetyl Alcohol (C16) and Stearyl Alcohol (C18)—typically in 50:50 or 30:70 ratios—melting between 49 °C and 56 °C.

 Can Stearyl Alcohol act as a standalone primary emulsifier for oil-in-water (O/W) creams?
No, because Stearyl Alcohol has a bulky hydrophobic C18 alkyl tail and only a single small hydroxyl (-OH) headgroup, it is oil-soluble (effective HLB ~1.0 to 1.5; Required HLB ~15.5) and cannot emulsify oil in water by itself. Instead, Stearyl Alcohol acts as a synergistic co-emulsifier and lamellar gel-network structurant: when combined at a 3:1 to 6:1 ratio with a hydrophilic primary surfactant (such as Ceteareth-20, Steareth-21, Sodium Cetearyl Sulfate, Potassium Cetyl Phosphate, or Behentrimonium Chloride), it self-assembles into hydrated alpha-crystalline bilayers that thicken the continuous water phase and stabilize the emulsion against phase separation.

 Why is Stearyl Alcohol essential in rinse-off hair conditioners and hair repair masks?
In rinse-off hair conditioners (typically dosed at 2.5 percent to 6.0 percent w/w alongside cationic surfactants like Behentrimonium Chloride or Cetrimonium Chloride), Stearyl Alcohol forms a viscoelastic lamellar liquid-crystalline alpha-gel network that builds rich cream viscosity and deposits a smooth, hydrophobic C18 lipid monolayer onto negatively charged, damaged hair cuticles. Compared to shorter-chain C14 or C16 alcohols, the longer C18 octadecyl chain of Stearyl Alcohol provides superior wet and dry combing lubricity, reduced frizz, and higher humid-climate conditioning durability.

 Why is high-purity (98%+) Stearyl Alcohol the preferred gellant for invisible solid antiperspirant deodorant sticks?
In anhydrous suspension antiperspirant sticks, 98%+ pure Stearyl Alcohol (dosed at 14 percent to 22 percent w/w along with 2 percent to 4 percent Hydrogenated Castor Oil) dissolves cleanly in warm cyclopentasiloxane or emollient esters at 70 °C and crystallizes upon cooling at 50 °C to 55 °C into a rigid, interlocking microcrystalline lattice. Its sharp 57 °C–60 °C melting point ensures that the deodorant stick remains hard and sweat-free during hot summer transport (> 45 °C), yet shears smoothly and invisibly onto underarm skin at body temperature without greasy residue.

 What is the difference between Stearyl Alcohol (CAS 112-92-5) and Stearic Acid (CAS 57-11-4) in formulation stability?
Stearic Acid (C18H36O2) contains an acidic carboxyl group (-COOH, Acid Value ~200 mg KOH/g) that requires alkaline neutralization to form soap emulsions, precipitates in acidic formulations (pH < 6.0) or hard water, and is incompatible with cationic hair conditioners and aluminum antiperspirant salts. By contrast, Stearyl Alcohol (C18H38O) contains a neutral primary hydroxyl group (-CH2OH, Acid Value <= 0.1 mg KOH/g) that is nonionic, completely stable from pH 2.0 to 12.0, and fully compatible with cationic quaternary ammonium compounds, acidic AHAs/BHAs, and multivalent metal electrolytes.

 How is Stearyl Alcohol used in USP-NF / Ph. Eur. pharmaceutical ointments and sustained-release oral tablets?
In topical pharmaceuticals, Stearyl Alcohol (compendial USP-NF / Ph. Eur. grade, >= 95.0 percent C18H38O) is used at 3 percent to 25 percent w/w (as in USP Hydrophilic Ointment) to stiffen petrolatum bases and increase their water-absorption capacity so aqueous drugs can be compounded into washable creams. In oral solid dosage forms, Stearyl Alcohol is melt-granulated or hot-melt extruded at 10 percent to 35 percent w/w with highly water-soluble APIs to form hydrophobic wax matrix tablets that provide controlled, sustained drug release over 8 to 24 hours.

 What major industrial surfactants, monomers, and polymer additives are synthesized from Stearyl Alcohol?
In chemical manufacturing, Stearyl Alcohol serves as the direct C18 primary alcohol feedstock for: (a) Ethoxylated nonionic surfactants (Steareth-2 to Steareth-100) via ethoxylation; (b) Stearyl Methacrylate (SMA) and Poly(Alkyl Methacrylate) (PAMA) pour-point depressants and viscosity index improvers for engine oils and crude oil pipelines; (c) Stearyl Dimethylamine and Quaternary Ammonium cationic surfactants (Behentrimonium / Steartrimonium / Stearalkonium salts); (d) Distearyl Thiodipropionate (DSTDP) polyolefin antioxidants; and (e) internal/external processing lubricants for rigid and flexible PVC extrusion.

 How can cosmetic brands, pharmaceutical manufacturers, and industrial buyers source Stearyl Alcohol and request COA, TDS, and SDS documents from Ataman Kimya?
Customers can procure Stearyl Alcohol (1-Octadecanol, CAS 112-92-5, EC 204-017-6) in both Standard Cosmetic/Compendial 95%+ (C18 >= 95%) and High-Purity 98%+ (C18 >= 98%) pastille and flake grades—packaged in 20 kg or 25 kg PE-lined bags, 500–1,000 kg FIBCs, or heated bulk road tankers and supported by batch-specific Certificates of Analysis (COA), Technical Data Sheets (TDS), and GHS/CLP Safety Data Sheets (SDS)—directly from Ataman Kimya by calling +90 216 577 10 10 or emailing info@atamankimya.com.

TECHNICAL SUMMARY

Stearyl Alcohol—universally recognized across international cosmetic, pharmaceutical, and chemical standards as 1-Octadecanol, Octadecan-1-ol, n-Octadecyl Alcohol, C18 Linear Fatty Alcohol, Ph. Eur. Alcohol stearylicus, INCI STEARYL ALCOHOL, and Stearil Alkol (CAS Number 112-92-5, EC / EINECS Number 204-017-6, Molecular Formula C18H38O, Molecular Weight 270.49 g/mol)—stands as the global benchmark saturated C18 primary fatty alcohol for lamellar emulsion stabilization, hair conditioning, anhydrous stick structuring, pharmaceutical sustained-release matrices, and specialty surfactant and methacrylate monomer synthesis. Engineered with high C18 chain purity (>= 95.0 percent to 98.5 percent+ 1-Octadecanol), a sharp melting range of 56.0 °C to 60.0 °C (solidification point 55.0 °C to 58.5 °C), a Hydroxyl Value of 200 to 215 mg KOH/g, ultra-low Iodine Value (<= 0.5 to 1.0 g I2/100 g), negligible Acid and Saponification Values (<= 0.1 to 0.5 mg KOH/g), and water-white melt clarity (APHA <= 10 to 20), Stearyl Alcohol delivers pH-independent stability (pH 2 to 12), oxidation-proof shelf life, velvety non-greasy emollience, and full compliance with USP-NF, Ph. Eur., BP, JP, EU Regulation 10/2011 (FCM No. 209), and US FDA 21 CFR 172.864 standards.

Ataman Kimya supplies premium, free-flowing Stearyl Alcohol Pastilles and Flakes across Cosmetic (INCI) Grades, Pharmaceutical Compendial (USP-NF / Ph. Eur.) Grades, High-Purity 98%+ Antiperspirant & Synthesis Grades, and Industrial Polymer Lubricant Grades in moisture-barrier 20 kg and 25 kg PE-lined bags, 500 kg to 1,000 kg FIBC big bags, and heated stainless-steel bulk tankers, backed by ready warehouse stock in Turkey, strict batch-to-batch analytical verification, and fast domestic and international logistics. To request a commercial quotation, bulk pallet or tanker pricing, laboratory evaluation samples, Technical Data Sheets (TDS), Safety Data Sheets (SDS), or a batch-specific Certificate of Analysis (COA) for Stearyl Alcohol (1-Octadecanol, CAS 112-92-5), please contact the technical sales team at Ataman Kimya using the contact details below.

Ataman Chemicals
Phone: +90 216 577 10 10
Email: info@atamankimya.com