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. CFPT 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
SDS available upon request.
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 CFPT?
- 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