Regarding flameproofing, we use wool and do not add other materials to the wool. In 2006, the CSPC enacted CFR 1633, which requires mattresses to pass an open flame test. A burner is placed on top of the mattress and the side for 60 and 90 seconds. After 30 minutes, the heat release must not exceed 200 kilowatts. The law does not require mattress manufacturers to use any flame retardants, but only pass the test. There are many companies, like Savvy Rest, Naturepedic, Lifekind, etc., use wool as the flame retardant and don't add other materials as well, but it is less common because wool can be 10 times or more expensive than a polyester and rayon FR solution.
While it isn't something that we offer, if you are concerned with chemicals and flame retardants and don't want wool or other materials, there are some options. With a doctor's prescription, you can purchase a mattress without wool or other flame retardants. If you haven't heard of it, www.themattressunderground.com is a decent resource for finding manufacturers who would be able to build a mattress to spec with a doctor's note.