On Monday, the National Park Service announced that electronic cigarettes are now banned in any national park area where traditional smoking is prohibited.

The NPS said the measure was taken as a “step to safeguard people’s health,” reports U.S. News & World Report. Vapor from e-cigarettes don't pose the same fire hazard as tradition cigarettes, and research has yet to conclude whether secondhand vapor from e-cigarettes poses the same health threat as traditional smoke—although many medical experts agree that vaping does carry some degree of health risk. 

“Protecting the health and safety of our visitors and employees is one of the most critical duties of the National Park Service,” National Park Service Director Jonathan Jarvis told U.S. News & World Report. “We are therefore extending the restrictions currently in place protecting visitors and employees from exposure to tobacco smoke to include exposure to vapor from electronic smoking devices.”

Last week, park service employees were given an internal memo about e-cigarettes which discussed various findings, including that the devices emit harmful chemicals like formaldehyde and a toxic compound also found in antifreeze.

But, advocates for e-cigarettes are unhappy with the announcement. Gregory Conley, president of the American Vaping Association trade group, says the restrictions are a “bad idea.”

"Outdoor smoking bans in parks can at least somewhat be justified by the risk of fires, but vapor products pose no more of a fire risk than a cellphone battery,” Conley said. “This behavior is shameful and any enforcement of the ban will constitute a great misuse of government resources. The National Park Service should leave ex-smokers alone and let them camp and hike in peace."

E-cigarettes vaporize liquid that is usually laced with nicotine. While little data is available on the long-term effects of the devices, health experts and researchers have produced opposing policy guidelines regarding public e-cigarette use. The potential impact can differ greatly depending on the user’s preferred vapor density and nicotine content of product inhaled.

Between 2000 and 2011, conventional smokers caused an estimated 1,000 fires across 12 states, costing $22 million in extinguishing fees and burn damage to 20,000 acres, according to a 2014 study published in the International Journal of Wildland Fire. The report notes that there has been a big decline in outdoor fires linked to cigarettes in recent years, which has been attributed to better firefighting techniques, including detecting the fire’s origin, but also big declines in the number of smokers throughout the country.

There are no reported cases of an electronic cigarette contributing to an outdoor fire, though the report cited the possibility of the devices’ powerful batteries to start a fire.

The National Park Service lands join a growing list of destinations, including New York City, that are banning the use of e-cigarettes in densely populated or public areas.