A Meals and Drug Administration official with appreciable energy over authorization choices for e-cigarettes and merchandise geared toward curbing smoking resigned on Tuesday to work for Philip Morris Worldwide, the worldwide tobacco conglomerate and maker of Marlboros.

The official, Matt Holman, was chief of the workplace of science within the company’s Heart for Tobacco Merchandise. In a memo to the employees on Tuesday, Brian King, the middle’s director, wrote that Dr. Holman had introduced that he can be leaving — efficient instantly — to hitch Philip Morris. The memo mentioned Dr. Holman had been on depart and, in keeping with company ethics insurance policies, had recused himself from all tobacco middle work “whereas exploring profession alternatives outdoors of presidency.”

Mr. King lauded Dr. Holman’s 20 years of labor on the F.D.A., the place he has lately been “making ready for and overseeing overview” of promoting functions for e-cigarettes and different nicotine-delivery merchandise. Dr. Holman mentioned in an interview on Wednesday that his actual position at Philip Morris had thus far been broadly outlined however added that he would work on tobacco harm-reduction efforts and supply some enter on regulatory submissions to the company.

His resignation provides additional turmoil to the company’s tobacco management division, which is present process a overview ordered by Dr. Robert Califf, the company’s commissioner. The division additionally misplaced its longtime director, Mitch Zeller, who retired in April.

To critics, Dr. Holman’s transfer is a very regarding instance of the “revolving door” between federal officers and the industries they regulate; on this case, one which has garnered a excessive diploma of public mistrust. It has additionally raised questions on company approvals, together with that of Philip Morris’s IQOS, a “heat-not-burn” tobacco gadget, which some researchers have discovered troubling. IQOS is just not offered on the U.S. market now due to patent litigation, but when that had been resolved, the gadget may face recent F.D.A. evaluations.

Federal guidelines governing “revolving door” profession strikes don’t stop an official from overseeing regulatory issues one week and becoming a member of a company with merchandise underneath overview the following.

“That is authorized. That’s the underside line,” mentioned Dr. Michael Carome, director of the Public Citizen well being analysis group. “It’s such a revolving door transfer that actually undermines public confidence within the company.”

The federal guidelines do ban Dr. Holman from showing earlier than the F.D.A. on issues through which he “participated personally and considerably throughout authorities service.”

Dr. Holman mentioned that he consulted with company ethics attorneys earlier than beginning job discussions earlier this month. He mentioned he was drawn to Philip Morris as a result of he considered the corporate as being dedicated to the objective of shifting cigarette people who smoke to noncombustible and fewer dangerous merchandise.

“They’re taking the actions that I believe would align with such a objective,” Dr. Holman mentioned. “And that’s what actually drew my consideration to P.M.I. I’m going there to not assist them promote extra cigarettes, however the reverse.”

He dismissed “revolving door” criticisms, saying that if that had been his motivation, he may have left the company for business a few years in the past. However lawmakers and a few public well being specialists criticized Dr. Holman’s alternative and its impact on the F.D.A.’s decision-making.

“It’s embarrassing for the F.D.A., which sees itself as a public well being company, to have its staff go to an organization that may be a main producer of loss of life,” mentioned Micah Berman, an affiliate professor of public well being and regulation at Ohio State College.

Consultant Raja Krishnamoorthi, a Democrat of Illinois, was equally crucial. “The revolving door between F.D.A. and the industries it’s tasked with regulating is extraordinarily disturbing,” he mentioned in an announcement. “Whereas some, together with P.M.I., might argue that their rent is proof of P.M.I.’s alleged dedication to taking the well being impacts of its merchandise extra critically, I gained’t maintain my breath.”

As head of the F.D.A. science workplace, Dr. Holman performed a key position in approvals of digital cigarettes and comparable gadgets, which producers have needed to submit for overview to remain available on the market lately.

IQOS, the Philip Morris product that Altria has a license to distribute in america, was one of many authorized merchandise. It’s offered in Korea, Japan and different international locations. An organization spokesman mentioned U.S. gross sales had been anticipated to renew subsequent yr, however it may need to endure one other overview earlier than that.

Critics of the IQOS approval embrace Stanton Glantz, a retired professor of drugs, and his colleagues on the College of California, San Francisco, who revealed a examine saying the gadget contained toxins, some probably carcinogenic and a few at increased ranges than in flamable cigarettes. The company’s approval “disregarded legitimate scientific proof and misapplied the general public well being commonplace mandated by regulation,” the examine within the journal Tobacco Management concluded.

Dr. Glantz mentioned on Wednesday that Dr. Holman ignored one other main examine exhibiting that e-cigarette use — outdoors of managed research of quitting efforts — was not related to lowered charges of smoking. He mentioned approvals have completed little to take care of the issue of dual-use, or utilizing cigarettes and e-cigarettes, which is worse for total well being. Of Dr. Holman’s departure, Dr. Glantz mentioned, “good riddance.”

“He’s the one who signed off on these approvals,” he mentioned. “They take care of all of those points by ignoring it, by counting on out-of-date research.”

Among the many F.D.A.’s latest controversies was the choice in June to disclaim advertising and marketing authorization to Juul Labs’ e-cigarettes. Since then, the company has relented, asserting a overview of its resolution.

In a court docket submitting, Juul cited the authorization granted to Philip Morris as a cause it might seemingly prevail, saying IQOS was authorized though a dozen chemical substances in IQOS aerosols had been “‘probably genotoxic and/or carcinogenic’ and had been ‘current in increased focus[s]’ than in flamable cigarette smoke.”

Dr. Holman mentioned many company choices have their critics, however he believed IQOS authorization was warranted on a full overview of the information.

Philip Morris mentioned in an announcement that Dr. Holman “is dedicated to serving to current grownup people who smoke entry scientifically substantiated smoke-free alternate options whereas defending youth. We’re trying ahead to him becoming a member of our crew as we proceed to pursue a smoke free future.”

The corporate additionally lately employed Keagan Lenihan, a former F.D.A. chief of employees, as a vice chairman of presidency affairs.