Hi Sharmin,
The concern with Exjade is that when it is mixed using metal utensils or in a metal container, it will react with the metals, thereby reducing the effectiveness of the drug. Using stainless steel containers for water won't have any effect on Exjade which has already been taken. Stainless steel won't leach iron and the only warning is that if acidic food is kept in a stainless steel container for an extended period, that there might be some leaching of the metals. The stainless steel containers intended for drinks are quite safe to use. Just don't mix Exjade in them, to be on the safe side.