Hi udoknowjac,
That would depend on the natural latex percentage of the latex topper. Latex that uses a higher percentage of natural rubber that comes from a tree (or that only uses natural rubber except for the chemicals used to foam and cure the latex) would certainly be more natural than polyfoam or memory foam. Some polyfoam and memory foam do use a small percentage of polyols that are plant oil derivatives to replace the petrochemical polyols but this is only used to replace a relatively small percentage of one of the two main chemicals used to make polyfoam and memory foam (see post #2 here). There is more about the different types and blends of latex in post #6 here.
Synthetic latex is made primarily from petrochemicals but it is a very safe material and all the latex you are likely to encounter would be certified for harmful chemicals and VOC’s either by Oeko-Tex Standard 100 or Eco-Institut which have a little more stringent testing protocol than Certi-Pur.
ADMIN NOTE:Removed 404 page link | Archived Footprint 1: Certification according to OEKO-TEX® STANDARD 100 |Archived Footprint 2: eco-institut.de/en/product-testing/mattresses-bedding/
Phoenix