Wow, I've heard of hospitals requesting quilts be sturdily quilted, machine bound and washable in hot water, but the fire retardant is new to me. I agree with the comment about additional chemicals in a sick room.
Any fire retardant that you spray on, can't be washed, and any fabric manufactured to be fire retardant you probably wouldn't want to quilt with and would be cost prohibitive.
Did a bit of google research. Looks like this is a UK thing. Here's one site that sells bedding:
http://www.thomaskneale.co.uk/bed-li...ant-bed-linen/