It's called "hookah"-- a type of smoking found all over the Middle East and Asia, and now it's become very popular in the Bay Area.
With cigarettes banned in California restaurants, smoking in a San Francisco bar is a strange sight.
"I don't smoke cigarettes or cigars," said San Francisco resident Christina Rosa.
But at Kan Zaman on Haight Street, Christina Rosa unwinds with a few puffs from a hookah water pipe.
"It's a social thing. You just kind of like, smoke it and drink and talk," said Rosa.
The mixture smoked in a hookah is made of tobacco, molasses and fruit.
"Coconut, double apple, cherry, melon, mixed fruit, honey, apricot and strawberry. This is strawberry," said Kan Zaman server Chrystal Powell.
It's covered in aluminum foil and warmed up with charcoal.
The reason why you can smoke inside of Kan Zaman is the Hookah mixture has no tobacco inside of it. But researchers at UC Berkeley say it's not so much the hookah that you're smoking that can cause health problems, but the charcoal that keeps it warm.
"That probably means you're going to have the high carbon monoxide," said U.C. Berkeley professor Katharine Hammond, Ph.D.
U.C. Berkeley professor Katharine Hammond is the chair of the Environmental Health Sciences Department.
Her research on the health effects of cigarette smoke on flight attendants eventually led to the smoking ban in airplanes.
Hammond's latest research on hookah smoking was published in the Journal of the American Medical Association.
"We looked at carbon monoxide as one of the things that people are exposed to but its only one of probably hundreds of toxic chemicals that people get exposed to from water pipes," said Hammond, Ph.D.
She studied a group of students after an hour of hookah smoking.
"These students actually have twice as much carbon monoxide as people who smoke a pack a day," said Hammond, Ph.D.
At Kan Saman, server Chrystal Powell doesn't believe she's doing harm to her health.
"I don't leave and smell like smoke. I don't feel like anything is being too harsh to my body," said Powell.
Professor Hammond believes more research needs to be done on long and short term usage.
"How that accumulates, that's to be studied. But I certainly wouldn't want to do that to my body," said Hammond, Ph.D.