Is our handmade soap biodegradable. It seems like the answer should be "yes". But I have been searching the internet for more info and am just getting confused. What does saponification do to biodegradable oils? I did find this: To qualify as biodegradable, a substance must be 80% degraded in 28 days." I believe this is in soil. I have been looking for a list of biodegradable substances with no luck yet. I have been messing around with creating a "Dish Bar" soap and trying some stuff in my own kitchen. I like it a lot and would love to see if it would sell, but I'm wondering if I can put "Biodegradable" on the label or if that is a no-no. Also would have to confirm that that is the case first.