The toxins that Daffodils contain are in the bulbs and are fairly mild making someone that eats them rather sick although if a large enough quantity were consumed that might kill them. The stems and leaves may also contain a small quantity that apparently do not adversly affect the compost or the foods grown with that compost, because those iof us that have done that for years, or simply turned the Daffodil leaves into the soil have not expeirienced any ill affects from them.

So daffodils love compost, the question is does compost love daffodils?

The toxic compound in narcissus, and more broadly in Amaryllidaceae, is an alkaloid, common name lycorine. It is widely distributed in the plant, more concentrated in the bulbs. It is known to be quite toxic to mammals, including humans, and poisoning cases from eating leaves/stems etc. are documented. It has been implicated as a growth inhibitor in higher plants and some yeasts, but was also found to be a promoter in other yeasts.

While I couldn't find anything specific about lycorine degradation in composting, plant alkaloids (the class that includes many well known recreational chemicals) are typically consumed under thermophilic composting conditions at temps > 130 ðF. I suspect that many spent daffodils, lilies, amarlysis, etc. have been composted over the years without problem, so I suspect you're safe. I would not, however, be surprised to find that daffodils and their cousins decompose a bit more slowly due to possible microbial inhibition from the presence of lycorine. While I wouldn't be surprised I haven't seen anything to suggest that's the case, and I never heard of a problem composting any of those plants.

Most everyone I have ever talked with about this, including people that study toxins, tell me that the toxins in Daffodils rarely cause death in mammals because you would need to eat so many bulbs to get a lethal dose that you would be sick of them before you got there. The leaves do not taste very good so ingesting them probably is not going to happen, not even mixed in a salad.
That "urushiol" from poison ivy, sumac, and oak will eventually break down in compost should indicate that the process will also break down other materials. Also plants seldom will uptake stuff from the soil they do not need to grow.

Here is a link that might be useful: Toxins in Daffodils

Nothing to worry about.

The "toxins" in the daffodil stems are going to be "food" to the bacteria and fungi in the compost. They will break them down into harmless materials just like they break down the oleander toxins in my compost.

Would it be safe to compost a lot of daffodil and muscari BULBS?

It would be safe, I'm sure, but unless you managed very high temperatures they might well survive and grow wherever you spread the compost. If you could crush them first and destroy the base plate it would be less likely. But I'm trying to imagine a scenario where you'd want to compost daffs rather than plant them. Not so for Muscari - they can be a pain where they thrive.

BTW in my experience daffodil stems and foliage compost very fast, being largely water, even in my cold heaps.

This toxin is a distinct advantage in deer country. They won't touch daffodils.

There's nothing in the stems that would be difficult for a compost heap to decompose.

Lycorine is just another plant alkaloid ... as is caffiene, quinine and a bazillion others.

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