Hi Joenic,
As mark mentioned … there is a big difference between “green”, organic, natural, and safe and in the mattress industry these are often used interchangeably (and incorrectly) and more as marketing terms than factual terms. They all have very different meanings from each other.
Green means that from cradle to grave there is a lower carbon footprint. It has nothing to do with safety. For example if you have a polyfoam mattress that is shipped compressed then it would take less fuel to ship it (more would fit into the same container) which would make it more green than the same material shipped uncompressed. A material that can break down and decompose or be recycled at the end of its useful life is more “green” than a material that has to go into a landfill. Rebonded polyfoam (made from chemicals) for example is made from recycled scraps of polyfoam bonded together in a chemical resin and would be greener than the polyfoam because it is made from recycled materials even though it isn’t any “safer”.
You can read more about organic certifications in post #2 here and post #2 here. Even organic materials such as latex are allowed to use some percentage of chemicals to make the latex. There are sources of non organic wool for example which are probably higher quality and use more “organic” farming methods for the wool than some of the wool that has been certified as organic. Some of these choose not to certify their wool because the certification would only add to the cost of the wool.
Natural means that a material comes from nature and doesn’t necessarily indicate that a material is any “safer” than a material that isn’t natural. There are toxic substances that are natural as well (crude oil for example is a natural material since it comes from nature) and synthetic substances that are completely safe (food grade polyethylene for example).
A “chemical” is just a form of matter that has consistent properties and can’t be separated into its components by physical separation methods. Water for example is a chemical. In other words it’s the safety of chemicals that are the issue … not the fact that something is a chemical.
Something that is “safe” means that it is made out of materials that aren’t toxic to humans (or children) regardless of its origin. The most reliable way to know if a material is safe is based on either knowing exactly what the material is or is made from or testing for harmful substances and VOC’s.
There is more in post #2 here and the many posts and sources of information it links to that can help each person answer the very complex question of “how safe is safe enough for me?” and one of the links it includes is post #4 here which also talks about so called “green” mattresses.
Post #2 here also includes links to most of the better forum posts about mattresses and children that should also be helpful in deciding on the materials that you would prefer to use in a mattress for your son and they include many good sources as well.
I also agree with Mark in Texas that with the type of issues you were describing that a visit to a health professional would be the first place I would start.
Phoenix