Stearic Acid
CAS 57-11-4
| Product name | Stearic Acid |
|---|---|
| Synonyms | stearic acid triple pressed, octadecanoic acid, stearic powder, stearic acid 40/50/60 |
| C.A.S. number | 57-11-4 (stearic acid / octadecanoic acid - the CAS for the acid itself; EC 200-313-4). Commercial triple-pressed material is a MIXTURE and is normally additionally declared under CAS 67701-03-5 (fatty acids, C16-18), with palmitic acid CAS 57-10-3 as the principal co-component and myristic acid CAS 544-63-8 present at low level. |
| Molecular formula | C18H36O2 - CH3(CH2)16COOH (stearic acid). Palmitic acid, the main co-component, is C16H32O2. |
| Molecular weight | 284.5 for stearic acid itself (ILO ICSC 0568). A commercial 40, 50 or 60 grade is a fatty-acid mixture and has no single molecular weight; palmitic acid is 256.4. |
| Grade supplied against | Triple pressed, 40/50/60 grades |
| Appearance | White to pale cream waxy flakes, beads, prills, powder or crystals with a slight characteristic fatty or tallow-like odour |
| Product group | Surfactants & Oleochemicals |
| HSN code | 3823 11 00 |
| Country of origin | As stated on the producer’s documents for the lot supplied; confirmed at offer stage |
| Packing | 25 kg bag |
| Storage | Store in closed original bags, cartons or containers in a cool, dry, well-ventilated place away from heat, ignition sources, oxidisers and strong-smelling materials. Keep below about 30 C - flakes and beads soften, block and cake above that, and the product picks up odour readily. Where it is handled as a powder, apply combustible-dust precautions: earthing and bonding, dust extraction, no accumulation of settled layers, and no ignition sources. If it is held molten, keep the melt only a little above its melting point and limit exposure to air and to prolonged high temperature, both of which darken the product and raise the acid value; use stainless steel melt lines, and treat all hot lines and valves as burn hazards with guarding and PPE. |
| S. No. | Test parameter | Specification | Method |
|---|---|---|---|
| 1 | Description | White to pale cream waxy flakes, beads, prills, powder or crystals with a slight characteristic fatty or tallow-like odour | Visual |
| 2 | Identification | Conforms to the substance supplied | Instrumental or chemical test, per method agreed |
| 3 | Assay / grade | Triple pressed, 40/50/60 grades | Titrimetry or instrumental, per method agreed |
| 4 | Physical state | Solid at ambient temperature; often handled molten | Visual |
| 5 | Solubility in water | Practically insoluble in water - about 0.00005 g/L at 20 C (ILO ICSC 0568 states 'none'). Soluble in ethanol, chloroform, diethyl ether and hot organic solvents. It saponifies in aqueous alkali to form soluble soaps. | Per the test method agreed |
| 6 | pH | Not applicable - the product is practically insoluble in water, so no meaningful aqueous pH exists and producer SDSs record 'no data available'. Quality for this product is specified by ACID VALUE, saponification value, iodine value, titre (solidification point) and colour, not by pH. If a customer's specification sheet demands a pH, the correct answer is that it is not applicable, not an invented number. | Potentiometry on an aqueous suspension |
| 7 | Relative density | About 0.84-0.94 g/cm3. ILO ICSC 0568 gives relative density 0.94-0.83 (the range reflecting solid versus molten); producer data 0.90 g/cm3 for the solid and 0.85 g/mL at 75 C for the melt. Quote the temperature with any density figure for this product. | Pyknometry or gas displacement |
| 8 | Melting / freezing point | 69-72 C for pure stearic acid (ILO ICSC 0568). Commercial grades melt LOWER and over a range because of their palmitic acid content: producer data for triple-pressed grades gives 55-60 C and 62.5 C on different sheets. Use the melting range on your own certificate of analysis for the specific grade, not the pure-substance figure. | Thermal analysis |
| 9 | Boiling point | Above 300 C (producer data; one sheet gives 351.5 C for the palmitic component). It decomposes near its boiling point, so this figure has no practical processing use. | Distillation range |
| 10 | Flash point | 196 C closed cup (ILO ICSC 0568). Producer sheets for triple-pressed grades give above 200 C and 205 C. Auto-ignition temperature 395 C (ILO ICSC 0568); one producer sheet conservatively states above 250 C. The material is combustible but not flammable, and the dominant fire hazard is dust, not vapour. | Not applicable — the substance is not combustible |
| 11 | Additional parameters | To the specification agreed before order | As agreed |
Not regulated for transport · Class Not applicable - not a dangerous good under ADR, IMDG, IATA, DOT or TDG, whether solid or in heated/molten bulk · Packing group Not applicable
Proper shipping name: Not applicable - not regulated for transport
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