Chemically Talking, this molecule is "midway" involving Sorbitan Oleate and Sorbitan Trioleate, that means that it's also an attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, but in the ratio of 2:3 for this reason the "Sesqui" component within the molecule's name. Apple requirements no int