composting Castor bean

Can Castor bean plants be composted? Is the entire plant poisonous? Is it okay if the compost is not used for plants that will be eaten?

 

It's completely harmless once composted and may be used around crops or ornamentals.

Castor pomace.
http://gardeningsuccess.com/composting/page_37.html
http://books.google.com/books?id=N6...Q6AEwBQ#v=onepage&q=Composting castor&f=false

 

Interesting. Thanks. Is this also true of Rhubarb, then?

 

I see no reason it should be different.

 

I've always been told to never put Rhubarb leaves in vegetable garden compost, since they are toxic. Not an issue, then, I guess?

 

The oxalic acid is in many foods such as spinach.

http://oxalicacidinfo.com/

http://en.wikipedia.org/wiki/Rhubarb

Toxic effects
"Rhubarb leaves contain poisonous substances, including oxalic acid which is a nephrotoxic and corrosive acid that is present in many plants. The LD50 (median lethal dose) for pure oxalic acid in rats is about 375 mg/kg body weight,[15] or about 25 grams for a 65 kg (~140 lb) human. While the oxalic acid content of rhubarb leaves can vary, a typical value is about 0.5%,[16] so a rather unlikely 5 kg of the extremely sour leaves would have to be consumed to reach an LD50 of oxalic acid."