Two scientists from the National Environment Engineering Research Institute (NEERI), Nagpur have proved that clove oil has a strong antibacterial agent that can transform unclean, foul smelling and alkaline well water into clean and sweet water with "favourable mineral qualities." The discovery made by Hemant J Purohit and Manisha Kulkarni received US patent (Patent number 6929810) on August 16, 2005. According to their discovery, one teaspoon of the antibacterial formulation made from clove oil can disinfect one litre of water in six hours.