Manufacturers are not required to tell you all the chemicals they use in mattresses. Anyone can say anything. http://science.kqed.org/quest/2012/10/31/playing-whack-a-mole-with-flame-retardants/

Hi,

Best to ask them a trick question. Do the foams they use Pass Cal 117 standards? If the answer is yes, then its toxic. If the answer is no then the foam does not have any flame retardants - good for everyone.

They may need to check with their supplier to get you an answer.

Tell them you're considering cutting one of the mattresses down and using it as cushions that need to pass Cal 117.

As a side note, if they don't answer then it probably has flame retardants.