The ingredient in Cella that causes the allergic reaction (for some shavers, including me) is benzaldehyde. It's widely used to add an almond scent to a product, and can also be found naturally in bitter almond oil (but not in sweet almond oil). I am assured that the TFS soaps do not contain benzaldehyde. Not sure what almond oils they use, but TFS soaps work great on my skin. Actually there are only two ingredients in shaving soap I have to avoid (as far as I know): benzaldehyde, and eucalyptus oil. Everything else, including lanolin and citrus oil, is safe for me. YMMV; some people cannot stand lavender and citrus oils for a similar reason (allergy).