A group of health experts is asking the Food and Drug Administration (FDA) to restrict the amount of caffeine permitted in energy drinks, according to The New York Times.

Eighteen physicians, public health experts and researchers wrote a letter to the FDA on Tuesday, saying the move is needed to protect children and teenagers from the potential risks of consuming large quantities of caffeine.

“There is evidence in the published scientific literature that the caffeine levels in energy drinks pose serious potential health risks,” they wrote. “Younger individuals tend to have greater sensitivity to a given serving of caffeine than adults because they are more likely to have a lower body mass and are less likely have already developed a pharmacological tolerance from regular caffeine consumption.”

Monster Energy has been implicated in the deaths of five people, while the possible involvement of 5-Hour Energy has been cited in 13 deaths. In one case, a 14-year-old girl reportedly died of cardiac arrhythmia after consuming two 24-ounce Monster Energy drinks. The FDA also received 21 claims of adverse reactions, some which required hospitalization, associated with Red Bull.

Energy drink manufacturers say their products are safe, and the amount of caffeine in them is on a par with coffee and other commonly consumed drinks.

In January, a government report found the number of emergency room visits involving energy drinks doubled from 2007 to 2011, reaching more than 20,000. The report, from the Substance Abuse and Mental Health Services Administration (SAMHSA), found most cases involved teens or young adults. SAMHSA calls consumption of energy drinks a “rising public health problem.” The drinks can cause insomnia, headaches, seizures, fast heartbeat and nervousness, the report notes.