In today’s evolving world of tobacco and nicotine products, a topic that comes up time and time again is harm reduction: the concept that there’s a public health benefit in converting smokers to products that fall on the lower end of the nicotine continuum of risk, as opposed to an abstinence-only approach.

During his time at the FDA, Zeller has often acknowledged that there is a continuum of risk, with combustible cigarettes falling on one end and products such as FDA-sanctioned nicotine replacement therapies (NRTs) on the other.

“People are dying from tobacco-related diseases from the smoke particles, not the nicotine,” Zeller said in a June 2014 Legacy Foundation webinar.

That said, he seemed to stop short of a full embrace of tobacco harm reduction, at least when it comes to e-cigarettes and vape.

“I’ve participated in many discussions about the potential benefits of these new technologies, as well as the risk and harm they could cause,” Zeller said in the webinar. “The reality is it’s going to be some of both.”

In recent months, Zeller has seemed more open to harm reduction. While attending a 2017 NATO seminar, he said that “the debate for the last decade has been remarkably unproductive—a harm-reduction dialogue [may offer] common ground.”