If you’re going to have poly foam, you’re going to have flame retardants. You can’t use such incredibly flammable material and not protect it,” says Barry A. Cik, co-founder of the organic mattress company Naturepedic. Poly foam, the most common filling on the market, is found in mattresses, upholstered furniture, car seats, stuffed animals, pillows and more.
 
Cotton was the most common filler and flame retardants weren’t in everything before this inexpensive but flammable foam entered and took over the market in the 1960s, . “Flammability wasn’t an issue. Cotton doesn’t really burn,” explains Cik. “It will smolder. If you don’t douse it with water and you let it go and go, it will burn.

But it wont really burn in a serious quick way like polyurethane, which just goes up into a huge fire instantly.” At first polyurethane foam didn’t even contain flame retardants. But case after case of it accidentally catching fire (usually from cigarettes) and subsequent deaths resulted flame retardant requirements.