A soapmakers group in my neighborhood, asked me about the cause DOS. I gave them the following answer: DOS are the results of "oxidation." Oxidation occurs when the double bonds in a fatty acid chain are attacked by singlet oxygen radicals. In considering the potential for DOS, consider that oleic acid had only 1 double bond, while linoleic has 2, and linolenic has 3. Therefore, soaps higher in linoleic and linolenic will be more prone to the DOS. This information is also contained in their numerical description. . Oleic acid, a monounsaturated oil, is written (18:1), meaning it is an 18 carbon chain, with 1 double bond.. The polyunsaturates of most concern to soapers, are linoleic acid (18:2), an 18 carbon chain, having 2 double bonds, and linolenic acid(16:3) 16 carbons with 3 double bonds, and gamma linolenic acid (18:3) 18 carbons with 3 double bonds. Saturated fatty acids, by definition, have NO double bonds, and therefore, are less susceptible to oxidation. When considering an oil high in linolenic fatty acids (Flaxseed, kukui, macadamia, ect.) I don't really worry about whether it's alpha or gamma linolenic acid, since both have 3 double bonds. And, if you're looking for a natural antioxidant, ROE may be worth considering. ROE, and many other berries, are receiving a lot of attention right now. Unfortunately, only limited amounts of date are being published in their trade magazines, or in scientific journals, which offer articles on line, but at unaffordable prices. One last word of caution, Anti-oxidants and Preservatives are not the same thing. But, that's for another discussion.