Nanomaterials are highly active and reactive because of their extremely low size that ensures very high surface area. It has also quantum confinement effect that allows various functional properties. In the environment it will undergo agglomeration, enters inside natural bodies like plants, leaves, fruits etc. It can enter in to human bodies creating adverse effects. However the adverse effects concept is still under investigation. The presence in water bodies is detrimental to living animals and also bacteria etc. Some nanomaterials will be able to catalyze reactions. Overall, the tendency to agglomerate will be the main function along with entering in to bulk material as solid dispersion: the latter being very comfortable situation for the environment.