While many of us probably think of it as drinking water, bottled water is actually considered a food product in the U.S. Like other bottled beverages, it is regulated by the U.S. Food and Drug Administration (FDA) and must adhere to strict quality and labeling guidelines.

NSF International has been testing bottled water products for compliance with federal and state guidelines for many years, and the NSF mark appears on hundreds of bottled water brands, both domestic and imported.