Our 20 year old mattress complete with springs that punctured it, is now gone. They hauled it away last Wednesday along with every memory of raising 3 kids co-sleeping, our “co-sleeping” 14 yellow lab who went “home” last July and I never imagined I would long for it back as much as I do. Our new “traditional” mattress’ off-gassing is enough to make me want to vomit! I need a king sized, firm, possibly organic, 0% off-gassing mattress and the more I read the more I’m confused. Any insight would be helpful. I am currently sleeping on a twin blow-up mattress on the living room floor. 
Hi ConfusedMattressMom,
The first place to start your research is the mattress shopping tutorial here which has all the basic information, steps, and guidelines you will need to make the best possible choice … and know how and why to avoid the worst ones.
Once you are at step 3 … if you let me know your city or zip code I’d be happy to let you know about any of the better options or possibilities I’m aware of in your area.
I would also read post #2 here about organic, natural, and safe materials and the differences between each of them which may help you decide on the types of materials that will fit your criteria for “safety”.
Phoenix