12-hydroxystearic acid (12-HSA) is a saturated fatty acid with a hydroxyl group on its twelfth carbon. It is made from castor oil and is sold as white to cream flakes or powder.
Its main use is in lubricating greases. Lithium 12-hydroxystearate is a widely used thickener in multipurpose greases.
How 12-HSA is made
The usual route starts with hydrogenated castor oil. That oil is split, by hydrolysis, into fatty acids and glycerine. The fatty acid mix is mostly 12-hydroxystearic acid, with some stearic and other fatty acids. Glycerine is a valuable by-product.
The quality of the starting castor oil and the hydrogenation step both affect the final 12-HSA. Hydrogenated castor oil is explained in what HCO is and who buys it.
Who uses it
- Grease makers: 12-HSA is reacted with lithium or calcium hydroxide to form soap thickeners. Lithium complex greases also use it.
- Coatings and inks: as a rheology modifier and in some resin systems.
- Cosmetics: in sticks and creams, and as a raw material for esters.
- Plastics: as a lubricant and in some metallic soaps such as zinc or calcium stearate types.
- Chemical makers: as a starting material for esters, amides and other derivatives.
Specification points
Buyers usually set limits on the items below. Numbers vary by supplier and grade, so take any figure on a datasheet as typical, not a standard.
- Acid value: confirms the product is mostly free fatty acid.
- Hydroxyl value: indicates how much hydroxy acid is present.
- Iodine value: low, showing residual unsaturation from incomplete hydrogenation.
- Melting point: typically in the upper 70s °C, though datasheets vary.
- Colour: often measured on the Gardner scale after melting.
- 12-HSA content: by gas chromatography, often stated as a minimum percentage.
- Moisture, ash and residual nickel.
- Form: flakes or powder, with particle size for powder.
Buying 12-HSA from India
Most 12-HSA in world trade is made from Indian castor oil, and several plants in Gujarat produce it. Some make HCO and 12-HSA on the same site, others buy HCO. A plant that controls the full chain usually offers more consistent quality.
Ask for recent certificates of analysis from real shipments, not datasheet values. Check the test methods and whether your grease plant has approved the grade. Grease makers often run their own trial batch before approving a new source. For castor oil test basics, see acid value, iodine value and colour for castor oil.
12-HSA is usually packed in 25 kg bags on pallets. Keep it dry and away from heat to avoid caking.
How we help
We find Gujarat plants that make 12-HSA from their own HCO, audit the splitting and flaking lines and test samples at an NABL-accredited lab. Before loading, we check bags, lot codes and weights. Ask for a free sourcing review.