When the FDA issued a ban on JUUL products in the United States, JUUL pushed back against the rules, according to the Blue Hole New Consumer Report on October 16. While the future of the ban is uncertain, experts at Johns Hopkins helped clarify what we know and what we don't know about e-cigarettes.

Amid a whirlwind of regulations and backsliding, e-cigarettes and how they are marketed in the United States have been shrouded in a cloud of uncertainty for the past few months. All e-cigarette manufacturers in the United States must obtain FDA authorization to market and sell their products, but on June 23, the FDA ordered e-cigarette maker JUUL to stop selling the safety of its products, citing a lack of toxicological evidence. The next day, JUUL appealed to the U.S. Court of Appeals for the District of Columbia, and they were granted a temporary stay to allow U.S. consumers to continue using their products.

In July, the FDA temporarily suspended the marketing denial -- but did not revoke it -- citing additional scrutiny of scientific issues related to JUUL's products. Most recently, on Sept. 20, JUUL sued the FDA for refusing to disclose documents justifying the original ban.

The Juul-mandated law back-and-forth reveals a deeper truth about e-cigarettes: There are still many unknowns about their health effects. While the FDA's attempt to regulate JUUL products is part of the agency's broader effort to ensure that e-cigarette products meet public health standards, there is clearly still much that is moving about this issue - not just the ingredients in e-cigarettes, but how they are promoted. The center sat down with experts in the field to discuss what we know and are still seeking to learn about e-cigarettes and how the industry is reaching its audience.

What we know: How vaping products are marketed

E-cigarette products are often marketed as a safer alternative to cigarettes, providing an alternative source of nicotine with less health risks. However, Carsten Prasse, an assistant professor at the Whiting School of Engineering, said the number of new nicotine consumers, especially young people, suggests the appeal of these products extends beyond those trying to quit. The e-cigarette industry has made a big push to specifically target young people, he said, citing fruit and candy flavors as examples.

It's not safe - whether you're vaping or near someone who is, says J. Michael Colaco, a professor of pediatrics at Johns Hopkins School of Medicine.

Joanna Cohen, director of the Institute for Global Tobacco Control at the Bloomberg School of Public Health, said that in the United States, companies cannot make health-related claims unless they get approval from the FDA. Marketing e-cigarette products as a safer alternative to cigarettes then requires such approval through a process known as Modified Risk Tobacco products, or MRTP. There were only 15 MRTP orders for low-nicotine or smokeless tobacco products, and no MRTP orders for e-cigarette products.

While the risks of e-cigarettes compared to cigarettes may not be fully understood, J. Michael Collaco, professor of pediatrics at Johns Hopkins School of Medicine, points out a key difference: e-cigarette solutions contain carrier agents and flavoring agents, which cigarettes do not, and these chemicals and compounds carry their own risks. Although e-cigarette products are marketed as a safe alternative to cigarettes, youth use of e-cigarette products is associated with a 350 percent increased likelihood of starting smoking.

We are trying to understand: the impact of chemicals on users and the environment

Plath said the idea that vaping products offer a healthier alternative to cigarettes is rooted in an assessment of the toxic chemicals in cigarettes. While chemical concentrations in e-cigarette products are lower, that doesn't mean there aren't other contaminants that pose equal or worse risks to users and the environment.

"There are a number of studies, including our own, that show the presence of a large number of other chemicals in e-cigarette sols." "Plath said. "For most compounds, we don't even know exactly what they are."

He said there is little oversight of the chemicals used by e-cigarette companies, whether it's what the chemicals are or the quality of the ingredients. For example, one of the compounds most likely to cause lung damage associated with e-cigarette use or vaping is vitamin E acetate, he said.

"As a consumer, you might think that having vitamins in an e-cigarette is healthy." "Plath said. "However, people need to understand that vitamins are often ingested rather than inhaled, which can make a big difference."

What takes a while to sink in: long-term health effects

Because e-cigarette products are still relatively new, it is difficult to determine the range of long-term health effects to users. However, based on studies in mice, Collaco said prenatal and neonatal e-cigarette exposure is suspected to cause changes in lung structure that may last a lifetime. There are not enough long-term data to know whether adolescent use of these products affects lung function in adulthood, but Collaco does recognize other known respiratory health effects: increased coughing, bronchitis, and asthma episodes and increased respiratory infections and lung injuries.

Secondhand smoke exposure has the potential to be as high as nicotine cigarettes, and in animal studies, fetal and infant e-cigarette exposure has been associated with reduced growth and eventual adult behavioral changes, including short-term memory deficits, hyperactivity, and increased anxiety.

"It's not safe -- whether you're vaping or near someone who's vaping." "Mr. Colaco said. "And it's definitely not water vapor."