Doctors and lawmakers in California want cannabis producers to warn consumers of health risks on their packaging labels and in advertising, similar to requirements for cigarettes. They also want sellers to distribute health brochures to first-time customers outlining the risks cannabis poses to youths, drivers and those who are pregnant, especially for pot that has high concentrations of THC, the chemical primarily responsible for marijuana’s mental effects.

“Today’s turbocharged products are turbocharging the harms associated with cannabis,” said Dr. Lynn Silver with the Public Health Institute, a nonprofit sponsoring the proposed labeling legislation, SB 1097, the Cannabis Right to Know Act.

Californians voted to legalize recreational pot in 2016. Three years later, emergency room visits for cannabis-induced psychosis went up 54% across the state, from 682 to 1,053, according to state hospital data. For people who already have a psychotic disorder, cannabis makes things worse – leading to more ER visits, more hospitalizations and more legal troubles, said Dr. Deepak Cyril D’Souza, a psychiatry professor at Yale University School of Medicine who also serves on the physicians’ advisory board for Connecticut’s medical marijuana program.

But D’Souza faces great difficulty convincing his patients of the dangers, especially as 19 states and the District of Columbia have legalized recreational marijuana.

Legalization is not the problem, he said; rather, it’s the commercialization of cannabis – the heavy marketing, which can be geared toward attracting young people to become customers for life, and the increase in THC from 4% on average up to between 20% and 35% in today’s varieties.

Limiting the amount of THC in pot products and putting health warnings on labels could help reduce the health harms associated with cannabis use, D’Souza said, the same way those methods worked for cigarettes.

He credits warning labels, education campaigns, and marketing restrictions for the sharp drop in smoking rates among kids and teens in the past decade.

“We know how to message them,” D’Souza said. “But I don’t think we have the will or the resources, as yet.”

Some states, including Colorado, Oregon and New York, have dabbled with cannabis warning-label requirements. California’s proposed rules are modeled after comprehensive protocols established in Canada: Rotating health warnings would be set against a bright-yellow background, use black 12-point type, and take up a third of the package front. The bill suggests language for 10 distinct warnings.

Opponents of the proposed labels say the requirements are excessive and expensive, especially since marketing to children is already prohibited in California and people must be 21 to buy.

“This bill is really duplicative and puts unnecessary burdens on the legal cannabis industry, as we already have incredibly restrictive packaging and advertising requirements,” said Lindsay Robinson, executive director of the California Cannabis Industry Association.

The state should focus more on combating the illicit pot market rather than further regulating the legal one, she said. Legal dispensaries are already struggling to keep up with existing rules and taxes – the state’s 1,500 licensed pot retailers generated $1.3 billion in state tax revenue last year. Adding more requirements makes it harder for them to compete with the illicit market, she said, and more likely to go out of business.

“The only real option if they fail out of the legal system is to shutter their businesses altogether or to operate underground. And I don’t think the state of California, with the tax revenue, wants either of those to happen,” Robinson said. “The heart of the issue is that there’s a massive, unregulated market in the state.”

KHN ( Kaiser Health News) is a national newsroom that produces in-depth journalism about health issues. Together with Policy Analysis and Polling, KHN is one of the three major operating programs at KFF ( Kaiser Family Foundation). KFF is an endowed nonprofit organization providing information on health issues to the nation. This story is part of a partnership that includes KQED, NPR and KHN.