Is it illegal in the state of California to eat an orange inside of a bathtub. If So whats the PENAL CODE of this law?

This is in fact not a law. There are no illegal substances involved and if you are doing this in you own home they have now way of prosecuting it. The myth that it can cause an explosion in the septic tanks is not true otherwise they would have to make it a law not to peel and orange in you sink. Also the same acids found in an orange are present in most real orange juices and there isn't a law saying you cant pour Orange Juice down your drain. All of those factors prove there is no logic behind this and that it is just something people wanna believe when it is infact not a law.