The battle over the testing and safety of bottled water landed on Capitol Hill Wednesday, as a Senate subcommittee on held a hearing on the quality and environmental impact of bottled water.

The primary issue: whether bottled water could actually be less safe than tap water.

Opponents point out that while utilities are required to test tap water for contaminants and disclose the results, the Food and Drug Administration has no such requirements for bottled water.

"We want the public to know that [its] bottled water is not necessarily cleaner and more pure than tap water," said Mae Wu of the Natural Resources Defense Council, a watchdog group. "We want them to know that it's not better regulated."

Wu was one of several critics of the industry who testified Wednesday, saying the public is misinformed about what's in their water.

But an industry spokesman disagreed.

"People should have a choice -- it's about choice. And that's the fundamental issue," said Joe Doss of the International Bottled Water Association, who denied bottled water is any less safe than tap water.

Another concern raised at the hearing was the bottles themselves.

Critics say there is mounting evidence that a plastic used in some water bottles contains bisphenol-A, a substance linked by research to cancer.

"I've heard different things about when you keep the bottle in the refrigerator, when the bottle gets too hot, when the bottle goes in the freezer -- what kind of chemicals are released from the bottle to your water," said Kimberly Jackson, a consumer.

The International Bottled Water Association admits the FDA is in the process of reviewing the safety of the plastic, but says right now, it considers the packaging -- and the product -- safe.

"Any actions or any efforts that would discourage consumers from drinking a safe, healthy product we think is not in the public interest," said Doss, the industry spokesman.

The bottled water industry says if any consumer wants more information about the quality of his or her water, he or she can call the 1-800 number on the bottle.