In a spirited showdown on “Good Morning America ” today, ABC News Health and Medical Editor Dr. Richard Besser confronted Dr. Mehmet Oz on what he called “extremely irresponsible” statements made on “The Dr. Oz Show” show Wednesday concerning arsenic in apple juice.

“Mehmet, I’m very upset about this, I think that this was extremely irresponsible,” Besser said. “It reminds me of yelling fire in a movie theater.”

“I’m not fear-mongering,” Oz fired back. “We did our homework on this risk.”

Oz’s appearance on ‘GMA’ is the latest development in a story that likely has many parents on edge about whether to continue serving apple juice to their children.

Oz and the show’s producers drew criticism for Wednesday’s episode of the “Dr. Oz Show,” which focused on the dangers of trace levels of arsenic present in many popular brands of apple juice. Juice manufacturers, government regulators and scientists said the results of what the program called its “extensive national investigation” were misleading and needlessly frightening to consumers.

According to the “Dr. Oz Show,” a laboratory tested “three dozen samples from five different brands of apple juice across three American cities” and compared the levels of arsenic to the limits of arsenic for drinking water set by the Environmental Protection Agency (EPA). They found 10 samples of juice with arsenic levels higher than the limits for water.

In a statement, the U.S. Food and Drug Administration said, “There is no evidence of any public health risk from drinking these juices.”

The FDA sent a letter to the Oz show Sept. 9, five days before the show was to air, which warned that airing the show would be “irresponsible” and “misleading” because the testing ignored that there are two forms of arsenic: organic and inorganic. Organic is generally thought not to be harmful to health, whereas inorganic is.

The FDA also conducted its own tests of the apple juice investigated by the “Dr. Oz Show.” In some of the very same lots of juice tested for the show, the FDA reported finding very low levels of inorganic arsenic; 6 parts per billion at most, even lower than the 10 parts per billion recommended by the EPA as a safe level for drinking water.

Oz acknowledged that “no children are dying from acute lethal arsenic poisoning,” stating instead that his concerns were about the long-term effect of arsenic exposure.

Still, Besser said Oz was implying to parents that drinking apple juice poses a risk to kids’ health.

“You have informed parents they are poisoning their children,” he said, a charge that Oz denied.

“We just want to have the conversation, and we’ve been trying to make this conversation happen,” Oz said.

He also added, “I would not take apple juice out of my kids’ containers now.”

ABC News’ Carrie Gann contributed to this report.