We put the leaves in the compost bin and there were never any problems. Growing up, my dad told us that the poisonous parts of the leaves do not get absorbed by the root system of plants when using the compost in a garden or flower beds. We laid the leaves out flat to create a layer to readily compost and, as my dad said, 'the leaves will be more diluted with the rest of the stuff'.
Rules he gave us:
Never cut rhubarb as the stems may rot.
Pull gently toward you, then pull to the side and twist. Ripe rhubarb should 'snap and pop' right out when pulled the right way (His Way). The crowns of the rhubarb will remain and keep the plant strong.
Always wait 2 years to harvest new plantings.
Stop pulling rhubarb by the 4th of July. Leave the plant alone and there should be another harvest in the fall.
Never pull a stalk less than 10-12" in length.
Never take more than half of the plant during the harvesting season.
Thinning out the rhubarb is good for the plant-don't let the plant go without harvesting some during the season.
Don't pull the stems all in the same spot of the plant. You will have bald rhubarb.
And we all listen to our dads, right?
Mmmmm....warm, sweetened, cooked rhubarb over vanilla ice cream.