Juul, the fast-growing e-cigarette startup recently valued at $15 billion, had to deliver awkward news to its employees last week.

The mandate arrived via email from CEO Kevin Burns on Dec. 11. Effectively immediately, vaping was officially banned inside the Juul offices.

Its 800 employees are no longer allowed to use Juul products in the office. If employees want to vape, they now have to go to the Silicon Valley version of smoker's lounge: a tent outside the office.

Wall Street Journal reported the news:

"It may feel nonsensical to prohibit at-work use of the very products we work hard to create and promote," Burns' email said, "But the bottom line is we need to comply with legal requirements the same as any company."

Since 2016, e-cigarettes have been included in California's statewide smoking ban, which covers workplaces, many public spaces, restaurants, and bars. Juul hadn't been enforcing the ban in their own offices. Now they're complying.

This isn't the first time Juul has come under fire. The last few months have been rocky for the most popular e-cigarette on the market. The FDA conducted a surprise inspection of Juul headquarters earlier this year, seizing thousands of documents about the company's marketing and sales practices.

To address claims that Juul targeted their products towards teens, the company suspended retail sales of flavored e-cigarettes and shut down its Facebook and Instagram profiles. Though Juul is no longer selling mango, fruit, creme, and cucumber flavors in retail stores, mint and menthol flavors are still sold. Truth Initiative, a non-profit that works to reduce the popularity of tobacco products among teens and young adults, found that mint is the most popular Juul flavor among 12-to-24 year olds.

Despite its rocky relationship with the FDA, the company is still going strong. The Altria Group, the parent company of Marlboro, is reported to be in talks to buy a minority stake in Juul. It's become so popular, the brand name has become a verb.