<prompt> The safe- limit of fluorine in drinking water is0.2 -0.5 mg L0.5 - 0.8 mgL0.8-1.2 mgL1.2-2.0 mgL  <response>: B. i.e. 0.5 - 0.8 mgL 494,586- Park 19th 540 - Park 20thFLUORINE - often called two - edged sword The recommend level of fluoride in drinking water in this country is accepted as 0.5 - 0.8 mgL Use of fluoride - to prevention of dental caries Fluorine is essential for the normal mineralization of bones and formation of dental enamel Intemperate countries where the water intake is low, the optimum level of fluoride in drinking water is accepted as 1 - 2 mg per litre 