SACRAMENTO, California (AP) ― California health officials Wednesday declared electronic cigarettes a health threat that should be strictly regulated like tobacco products, joining other states and health advocates across the U.S. in seeking tighter controls as “vaping” grows in popularity.

The California Department of Public Health released a report saying e-cigarettes emit cancer-causing chemicals and get users hooked on nicotine but acknowledging that more research needs to be done to determine the immediate and long-term health effects.

“E-cigarettes are not as harmful as conventional cigarettes, but e-cigarettes are not harmless,” said California Health Officer Ron Chapman. “They are not safe.”

New generations of young people will become nicotine addicts if the products remain largely unregulated, Chapman said. Last year, 17 percent of high school seniors reported using e-cigarettes, known as vaping, according to the report.

“Without action, it is likely that California’s more than two decades of progress to prevent and reduce traditional tobacco use will erode as e-cigarettes renormalize smoking behavior,” the report says.

E-cigarettes heat liquid nicotine into inhalable vapor without the tar and other chemicals found in traditional cigarettes. A cartridge of nicotine can cost anywhere from $5 to $20 and can be reused.

California banned the sale of e-cigarettes to minors in 2010, but the report raises concerns about children consuming liquid nicotine with flavors such as cotton candy and gummy bears.

Reports of children under 5 with e-cigarette poisoning jumped from seven in 2012 to 154 last year.

The California report says e-cigarettes emit as many as 10 toxic chemicals, but advocates say there is no evidence those substances are released at dangerous levels.

“Despite the health officer’s false claims, there is ample evidence that vaping helps smokers quit and is far less hazardous than smoking,” Gregory Conley, president of the e-cigarette advocacy group American Vaping Association, said in an email.

“Smokers deserve truthful and accurate information about the relative risks of different nicotine products, not hype and conjecture based on cherry-picked reports.”