Apparently kids PVA is safe but surely they dont use this the only other 'safe natural' glue i can think of is Elmers which alot of people say is animal freindly ect as it is made with natural materials but this is from their website:
Elmer's Glues are chemical based. They are made or formulated from chemicals which are synthesized (created by Man). These chemicals were originally obtained or manufactured from petroleum, natural gas and other raw materials found in Nature. The exact formula and specific ingredients used in making Elmer's products are considered proprietary information, therefore, we cannot share those with you.
Surely no glue can be completely safe :?