A recent study by researchers at the Lawrence Berkeley National Laboratory found that the emissions from an alternative to cigarettes called heat-not-burn, or HNB, are harmful and can lead to poor indoor air quality.

Published in May, the study focused on the new HNB brand — where tobacco is heated instead of burned — developed by Philip Morris International, or PMI, called IQOS. An IQOS device has three parts: a heated tobacco unit, an IQOS holder and a charger. The consumer pushes a button on the device to draw in the “nicotine-containing vapor” created by the heated tobacco, according to the PMI website.

The research team studied these emissions in two ways. The first through mainstream emissions, which contain chemicals that consumers inhale; the second through sidestream emissions, which contain chemicals that are not inhaled by the consumer and can go into the air.

“We identified and quantified chemicals emitted by a heat-not-burn device, and found that emissions were lower than those from conventional cigarettes,” said co-author and deputy chemist of the Berkeley Lab Indoor Environment Group Hugo Destaillats in an email. “However, many of these compounds were emitted at levels that were comparable or higher than electronic cigarettes we had studied previously using the same methodology.”

According to the study, users do not have control of the heating power and duration when using an IQOS device, because these conditions are set by the manufacturer.

The study found that sidestream and exhaled mainstream emissions generated by this process increase indoor pollutant levels through the release of 33 “volatile” organic compounds found in the emissions.

“We know next to nothing about the risks of vaping,” said campus professor David Presti in an email. “While we are beginning to see serious adverse effects, it may take years before the full extent of the health consequences are revealed.”

In April, the Food and Drug Administration announced that it authorized the sale of IQOS in the United States, but has placed “stringent” marketing restrictions on the product in an attempt to prevent youth access and exposure to the device. IQOS has been sold in more than 40 countries in Asia, Europe, Africa, and South and Central America during the last four years.

According to the press release, IQOS underwent a “rigorous” review through the premarket tobacco product application.

“Ensuring new tobacco products undergo a robust premarket evaluation by the FDA is a critical part of our mission,” said director of the Center for Tobacco Products Mitch Zeller in a press release. “While the authorization of new tobacco products doesn’t mean they are safe, the review process makes certain that the marketing of the products is appropriate for the protection of the public health.”