@sueinmn Excellent information Sue! I’ll add that there is a product called AFM Safecoat for sealing wood products to stop out gassing. I used this when our house was built and sealed all the plywood subfloors before pre finished hardwood was laid on top. I also sealed the bottom of countertops and edges of cabinets because they are usually MDF with a fake wood layer over it, and then the doors are real wood. This was possible because we had access during construction. We also had them use formaldehyde free insulation and this made a big difference in reducing formaldehyde from building materials. We have no carpet, just hardwood and ceramic tile. There are also wall paints that are low VOC.