I'm actually chemically sensitive and when I found myself needing a new mattress for my adjustable bed, I was terrified of what was out there. I finally settled on the green cotton mattress from
White Lotus. You can get a mattress with only boric powder used a flame retardant without a prescription. (I've yet to find a doctor in my town with common sense, so I was reluctant to rack up bills trying to find one to write a prescription.) I was understandably hesitant about ordering, but I've been pleased with the results. It is firmer than a foam mattress, but there is absolutely no chemical smell (and I would know if there was even a tiny one). I believe foam would be softer, but I am afraid of foam, too. I think they make it out of soy and I give soy a wide berth.
Anyway, if you sign up for the newsletter, they have pretty good sales periodically. That's what I did and got a pretty good deal. Be warned that the green cotton mattress without foam is more like a futon mattress but it works perfectly for my adjustable bed. BTW, I replaced one of those dial-a-firmness beds with the air bladders in each side and I hated it! It was prohibitively expensive and I had to replace the air bladders three times in 7 years and once it wasn't even the side I sleep on. Plus, it reeked of chemicals......I don't recommend them. For the chemical smell, I had a zip-up mattress cover from
National Allergy. The nylon ones reek of chemicals so the all-cotton is the way to go. They are expensive, but it does help cut down on the amount of chemicals you breathe in your sleep if you have a conventional mattress.