Hi HermitageBrewing,
There is more to mattress “safety” than just the flame retardants used and Post #2 here and the links it includes to other posts and sources of information is a good place to start your research into all the complex, conflicting, and often contradictory information that can help you answer the question of “how safe is safe enough for me (or your children)?”
This article along with post #4 here and post #2 here has more information about the different types of fire retardants used in mattresses and which ones may be “safer” than others.
It’s illegal to sell a mattress that doesn’t pass 16 CFR 1632 and 1633 (without a prescription from a health professional) but there are many methods used to pass the tests that don’t involve the use of flame retardant chemicals.
If you let me know your city or zip code I’d be happy to let you know of the better options I’m aware of in the area and you could call them to see if any of them will make a mattress that doesn’t use chemical fire retardants or whether they can make a mattress with no fire retardants at all.
Just in case you haven’t read it yet … post #1 here has all the basic information, steps, and guidelines that can help you make the best possible choices and includes a link to a list of the online members here that sell component mattresses that use either viscose/silica or wool as the fire barrier.
No matter how “safe” the fire retardant methods or the materials and components in a mattress may be … it also needs to be a great match to your specific needs and preferences in terms of PPP.
Phoenix