Heneicosanoic acid

Heneicosanoic acid (CAS 2363-71-5) is a saturated straight-chain fatty acid containing 21 carbon atoms, commonly referenced as C21:0 or Heneicosylic Acid. It carries no assigned E-code and is not listed in standard food additive registers. It belongs to the odd-chain fatty acid group, distinguishing it from the more common even-chain series.

In personal care formulations, C21:0 functions as an emulsifier by integrating into lipid bilayer structures, improving interfacial stability between aqueous and oil phases. In lubricant and metalworking applications, it acts as a boundary lubricant, reducing metal-to-metal friction through adsorption onto surface active sites. Researchers and formulators also use it as an analytical reference standard for odd-chain fatty acid profiling.

Heneicosanoic acid is supplied as a white shiny fluffy crystalline powder and is available in research and technical grades. The substance is registered under REACH (EC 219-113-3) and is classified under HS code 29159000. Packaging formats typically include small-quantity laboratory units and bulk options for industrial procurement.