PVA, PVAc glue (Polyvinyl acetate), or white glue, is the most used glue in wood construction nowadays. It is a product of the petrochemical industry. It can be seen as microscopic plastic particles diluted in water. Even though it is a synthetic thermoplastic, under the right conditions, it biodegrades. Overall it is considered as a safe product to use. Also used for bookbinding and paper crafting, or as a protective coating for cheese. Yummy.