Chemically speaking, this molecule is "halfway" between Sorbitan Oleate and Sorbitan Trioleate, this means that it is also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but in a very ratio of two:3 consequently the "Sesqui" portion in the molecule's identify. We do a Best of INCIDeco