Smoking in federal prisons, which has been banned in practice since 2006, has been officially outlawed, according to U.S. News & World Report. Prison guards will still be allowed to possess tobacco.

Under the law, possession of tobacco of any kind by inmates will be prohibited. They will only be permitted to smoke for religious purposes. According to Bureau of Prisons spokesman Ed Ross, tobacco products were taken off the shelves of prison commissaries in 2006.

If an inmate is caught with tobacco they can face discipline, possibly including loss of phone or visitation privileges, Ross said. “I think it’s just formalizing the policy that’s in place.”

The rule applies to the more than 212,000 inmates in federal facilities. Many state and local jails have also banned tobacco use, the article notes.

While the 2006 rule did not ban possession of tobacco, it became impossible for inmates to obtain tobacco once commissaries stopped selling it. Before tobacco was banned from commissaries, an estimated 60 to 80 percent of inmates were smokers. Public health advocates said smoking harmed the health of smokers and nonsmokers, who were exposed to significant amounts of secondhand smoke due to poor ventilation in prisons.

Banning cigarettes has led to a surge in black market prices for cigarettes. Last year The New York Daily News reported the price of a pack of cigarettes in city jails had jumped to as high as $200.