Natural wood stain is suitable for for a baby's room as long as it is VOC free. VOCs or volatile organic compounds are additives often used in wood stain and paint that emit toxic fumes and can be harmful if a baby happens to put her mouth on the railing—which, of course, will happen. Look for VOC free primer, sealer and wax as well to keep baby safe. Natural does not mean 'all natural' in all instances. There are paints that are low-VOC as opposed to VOC-free, which are not recommended for cribs.