With marijuana now legal for adults 21 years old an up in Connecticut, effective July 1, here are some highlights of the new law that makes the state the 19th to legalize recreational use of cannabis.

How much cannabis will be allowed?

The new law allows adults up to 1.5 ounces on their person and 5 ounces in their home or locked car. It also wipes out previous convictions for marijuana possession of up to 4 ounces.

Where can you purchase recreational-use cannabis?

Not in Connecticut. The law suggests the first retail marijuana businesses will open in mid-2022, possibly later. Until then, Massachusetts dispensaries expect an uptick in business from new customers traveling across the state line. Most dispensaries sell cannabis in multiple forms, such as flower, edibles, concentrates and tinctures.

What are the risks of using marijuana?

Dr. J. Craig Allen, vice president of addiction services for the Behavioral Health Network and medical director of Rushford, says the drug affects younger people differently. The new law prohibits marketing to underage people in marijuana advertising. Marijuana marketers cannot sponsor events where more than 10 percent of the people are expected to be under 21.

“It’s essential that we limit access to adolescents and young adults,” says Dr. Allen, “because their brains are still developing and are more vulnerable to the negative consequences of THC (tetrahydrocannabinol), the psychoactive component of cannabis.”

Here are the high-risk groups:

  • Adolescents.
  • Young adults under 24 years of age.
  • People with an existing substance use disorder or a history of one.
  • People with psychiatric disorders.
  • Women of childbearing age.

“The negative consequences include addiction and neuropsychiatric problems for young adults,” says Dr. Allen. “An age limit of 24 was not adopted in the bill, so it will be really important to provide education and information about the potential risks to that population.”

Can you grow marijuana in your home?

Starting Oct. 1, holders of medical marijuana cards can grow up to six plants. Effective July 1, 2023, any adult 21 and old can also grow six plants. The plants must be grown indoors.

Where can you smoke marijuana?

Every community with a population of at least 50,000 must designate at least one public space for marijuana use. Otherwise, the same rules as cigarette smoking allows. That means no marijuana in healthcare facilities, restaurants, state and municipal buildings and workplaces.

The workplace ban also prohibits smoking within 25 feet of an entrance. Hotels must prohibit guests from smoking marijuana. The new law also bans marijuana use in state parks, on state waterways and in motor vehicles by both drivers and passengers. (How will police assess driving while impaired by driving? Here’s a look.)