I just came here to ask about this! Because they are super expensive (like over $1000), I was hoping to get a futon (well I want a futon anyway.) that was organic or at least without the flame retardant chemicals. I was reading about this is
Your Organic Pregnancy (great resource by the way, whether you're pregnant or not). It was a little confusing though, and they don't recommend brands.
FWIW here are some websites that I'm currently bookmarking from the book. Haven't looked at them yet-Don't know how helpful they are if you can't just plunk down 1500 on a mattress. (i can't. :P)
http://www.coyuchi.com/http://www.daxstores.com/http://www.ecowise.com/http://www.thenaturalsleepstore.com/