F.D.A. Raids Juul Headquarters, Seeking Documents.

The Food and Drug Administration conducted a surprise inspection of the headquarters of the e-cigarette maker Juul Labs last Friday, carting away quite a thousand documents it said were related to the company’s sales and marketing practices.

The move announced on Tuesday was seen as an attempt to ratchet up pressure on the company, which controls 72 percent of the e-cigarette market within us and whose products have become popular in high schools. The F.D.A. said it was particularly interested in whether Juul deliberately targeted minors as consumers.

“The new and highly disturbing data we have on youth use demonstrates plainly that cigarettes are creating a plague of normal nicotine use among teens,” the F.D.A. said in a statement.

“It is significant that we take action to know and address the actual appeal of, and simple access to, these products among kids.”

F.D.A. officials described the surprise inspection as a follow-up to an invitation, the agency made for Juul’s research and marketing data in April.

Kevin Burns, Juul’s chief executive the officer said the corporate had already handed over quite 50,000 pages of internal documents to the F.D.A. in response to that request.

“We want to be part of the solution in preventing underage use, and we believe it will take industry and regulators working together to limit youth access,” he said.

In recent months, the F.D.A. has increasingly expressed alarm over the prevalence of vaping among youths in high school and even middle school, which it is commissioner, Dr.

Scott Gottlieb said had reached “epidemic proportions.”

The number of high-school students who used e-cigarettes within the past 30 days has risen roughly 75 percent since last year to about three million, consistent with preliminary unpublished data, confirmed by the F.D.A. Dr. Gottlieb has repeatedly noted that the candy-like names and flavors of the many vaping liquids seem intended to draw in younger users.

A RAND Corporation study of two,039 Californians from ages 16 to twenty beginning in 2015 through 2017, released Tuesday, offered new evidence for concern about teenage vaping.

Published within the journal Nicotine and Tobacco Research, the report said that as teenagers who used e-cigarettes grew older, many began smoking traditional cigarettes, which are more dangerous, as well.

By the top of the study period, over half of the e-cigarette users were also smoking cigarettes.

In another report released on Tuesday and published within the journal JAMA, the Centers for Disease Control and Prevention highlighted the dominance of Juul within the e-cigarette market.

The C.D.C. noted that Juul Labs’ sales soared from 2.2 million devices in 2016 to 16.2 million devices last year.

The C.D.C.’s figures only included those from retail stores, not the internet, which is also a major source of sales.

Other recent studies have also pointed out that teenagers are increasingly using vaping devices for marijuana consumption.

Many adult consumers of e-cigarettes say the devices have helped them move away from smoking traditional cigarettes, or quit entirely.

But the growing number of teenagers who haven't smoked also are turning to e-cigarettes, believing that they're relatively harmless products.

But though e-cigarettes do not have the carcinogens that come from burning tobacco, they, especially Juul, can have strong concentrations of nicotine, which is highly addictive, and detrimental to the developing adolescent brain.

In September the F.D.A. announced a flurry of fines and warning letters that it had sent to convenience stores for selling e-cigarettes to underaged customers.

(It is illegal to sell the devices to anyone under 18.) The agency said it might also, follow online sales, pointing out that bulk purchases were possible red-light indicators that a buyer might then resell devices to minors.

The agency has given Juul and 4 other e-cigarette manufacturers, a 60-day deadline to produce plans showing how they will limit access to teenagers.

Recently, it started its own multimillion-dollar campaign of posters for top school bathrooms and public service announcements on popular websites to warn teens of the dangers of vaping nicotine.