CAS 57-11-4 · Saturated Fatty Acid
Stearic Acid
Octadecanoic Acid · C₁₈H₃₆O₂ · MW 284.48 g/mol
A naturally derived C18 saturated fatty acid and one of the most widely used industrial chemicals in the world. Stearic acid's combination of lubricity, emulsification, and reactivity with metal oxides makes it indispensable in rubber vulcanization, plastics processing, personal care, candle manufacturing, and metalworking. Texas-Chem supplies stearic acid in bags, drums, and super sacks.
Formula
C₁₈H₃₆O₂
Melting Point
69.3 °C
Form
Flakes / Powder / Solid
Pack Sizes
Bags · Drums · Super Sacks
Structural Formula
C18 straight-chain saturated fatty acid — no double bonds
Safety & Regulatory
- NFPA Health
- 1 — Slight hazard
- NFPA Flammability
- 1 — Slight hazard
- NFPA Reactivity
- 0 — Stable
- OSHA PEL (TWA)
- Not established (nuisance dust: 15 mg/m³)
- ACGIH TLV (TWA)
- Not established
- DOT Hazard Class
- Not regulated
- UN Number
- Not assigned
- Packing Group
- N/A
- SARA 313
- Not listed
Low fire hazard — store away from heat and ignition sources. Always consult the current Safety Data Sheet before handling.
Grades & Packaging
Available Grades
Pack Sizes
Physical & Chemical Properties
| Molecular Formula | C₁₈H₃₆O₂ (CH₃(CH₂)₁₆COOH) |
| Molecular Weight | 284.48 g/mol |
| CAS Number | 57-11-4 |
| Appearance | White waxy solid, flakes, or powder |
| Melting Point | 69.3 °C (156.7 °F) |
| Boiling Point | 383 °C (721 °F) at 760 mmHg |
| Flash Point | 196 °C (385 °F) — Combustible solid |
| Density | 0.847 g/cm³ (liquid at 70 °C); 0.940 g/cm³ (solid) |
| Solubility in Water | Practically insoluble (<0.003 g/L at 20 °C) |
| Solubility in Organics | Soluble in ethanol, ether, chloroform, benzene |
| Acid Value | 195–200 mg KOH/g |
| Iodine Value | <4 (highly saturated) |
Industrial Applications
Rubber & Tire Manufacturing
Primary processing aid and activator in rubber compounding. Stearic acid reacts with zinc oxide to form zinc stearate, which activates sulfur vulcanization, improves dispersion of fillers, and acts as an internal lubricant to reduce mill sticking and improve flow.
Plastics & PVC Stabilization
Lubricant and mold-release agent in PVC, polyolefins, and engineering thermoplastics. Reduces friction between polymer chains during processing, prevents die buildup, and improves surface finish of extruded and injection-molded parts.
Personal Care & Cosmetics
Emulsifier, thickener, and emollient in lotions, creams, soaps, and cosmetics. USP/FCC grade stearic acid provides a smooth, non-greasy skin feel and stabilizes oil-in-water emulsions in pharmaceutical and personal care formulations.
Candles & Wax Products
Hardening agent for paraffin and soy wax candles. Stearic acid raises the melting point of wax blends, improves opacity and whiteness, reduces shrinkage on cooling, and enhances fragrance retention and burn time.
Metalworking & Lubrication
Boundary lubricant and metal-drawing compound. Stearic acid and its metallic soaps (calcium, zinc, magnesium stearate) are used in wire drawing, tube forming, and cold-heading operations to reduce die wear and improve surface quality.
Textile & Fiber Processing
Softening and finishing agent for natural and synthetic fibers. Applied as a fiber lubricant during spinning and weaving to reduce static, improve hand feel, and protect filaments from mechanical damage during high-speed processing.
Why Source Stearic Acid from Texas-Chem?
- 35+ years supplying fatty acids and specialty chemicals to Texas industry
- Industrial, Technical, USP/FCC, and Kosher/Halal grades stocked
- Flexible packaging from 50-lb bags to super sacks
- Competitive pricing backed by top-tier producer relationships
- Technical support and SDS documentation with every order
- Same-day quotes for standard quantities
Stearic Acid vs. Alternatives
Stearic acid is a saturated C18 fatty acid used as a lubricant, emulsifier, and rubber processing aid. Here's how it compares to related fatty acids.
| Attribute | Stearic Acid | Oleic Acid | Palmitic Acid |
|---|---|---|---|
| Carbon Chain | C18 saturated (no double bonds) | C18 monounsaturated (1 double bond) | C16 saturated |
| Physical State | White waxy solid (flakes or powder) | Colorless to pale yellow liquid | White waxy solid |
| Primary Use | Rubber, cosmetics, lubricants, candles | Cosmetics, lubricants, food | Cosmetics, food, surfactants |
| Melting Point | 69.3 °C (157 °F) | 13.4 °C (56 °F) | 63.1 °C (146 °F) |
| Oxidative Stability | Excellent — fully saturated | Good — one double bond | Excellent — fully saturated |
Industries We Supply Stearic Acid To
Rubber & Tire Manufacturing
Stearic acid is an essential activator in rubber vulcanization, forming zinc stearate with ZnO to improve cure rate and mechanical properties.
Stearic Acid supply in Houston, TXPersonal Care & Cosmetics
Used as an emulsifier, thickener, and emollient in lotions, creams, soaps, and cosmetic formulations — supplied in flake and powder form.
Stearic Acid supply in Dallas, TXPlastics & PVC Processing
Stearic acid and its metal salts (calcium, zinc stearate) are used as lubricants, mold release agents, and heat stabilizers in PVC and polymer processing.
Stearic Acid supply in Beaumont, TXCandles & Wax Products
Used as a hardener and opacifier in paraffin candles, increasing melting point and improving burn quality and appearance.
Stearic Acid supply in Fort Worth, TX