I believe IKEA does not put the fire retardant in their mattresses (although I don't know if they make them for cribs) as Sweden is apparently VERY strict about standards surrounding chemical use in products (so IKEA applies these standards to all their products, regardless of where they are to be sold).
Thomas - I slept with my kids on my chest too - the first son until he was 3 months old, and then he got too heavy as he is a big boy, so then he went on the adult bed when he required it (he still does actually). The second only required sleeping on my chest for the first week of his life, ( and then after that he would only sleep on the bed occasionally, and now not at all at 10 months old - amazing how siblings can be so different). I actually really like it until they get too heavy! I did this after the hospital lactation consultant recommended it after my first was born because my baby wouldn't sleep at all unless he was held. She also recommended that we sleep chest to chest, because while it's not safe for a baby to sleep on their tummies while in a crib/bed, apparently sleeping chest to chest actually helps to keep them going. The adult's body rhythms (breathing, heartbeat) help regulate the baby's systems. Kinda neat.