BOSTON – As the retail marijuana industry takes off in Massachusetts, lawmakers are gearing up to make major changes, again, to the state’s voter-approved pot law.

Dozens of proposals to expand or restrict the sale and use of retail marijuana were filed ahead of the two-year legislative session that got underway last month.

Much of the focus by Beacon Hill leaders aims at giving law enforcement more authority to target people suspected of driving while stoned. Other proposals would ease workplace rules that pot advocates claim are unfair, including bills that would prevent private employers from testing workers for marijuana.

“Businesses don’t test employees for alcohol, why should they be doing it for legal cannabis?” said Jim Borghesani, a marijuana industry consultant and spokesman for the 2016 campaign to legalize its use.

Meanwhile, opponents of legal weed are backing a number of plans to restrict where marijuana can be sold and used.

One would extend the 500-foot buffer between marijuana establishments and schools to include daycare centers “or any facility where children congregate.” Another imposes a blanket ban on “advertising, marketing and branding through promotional items, including giveaways, coupons, discounts, free or donated marijuana.”

“The commercialization of this drug is making a dangerous drug more harmful,” said Jody Hensley, a policy adviser for the Massachusetts Prevention Alliance, which opposed legalization. “And we’re dealing with a regulatory structure dominated by the cannabis industry, which has escalated the harms caused by this drug.”

Gov. Charlie Baker, a Republican who also opposed legalization, has filed legislation that, among other changes, would suspend the driver’s licenses of motorists who decline to submit to police demands for a blood, saliva or urine test. It and other proposed rules would mirror the penalties for suspected drunken drivers who refuse to take a Breathalyzer test.

Driving while under the influence of marijuana is illegal and punishable under the same laws against drunken driving. But there is no “implied consent” law in Massachusetts that requires drivers suspected of driving while stoned to submit to any such test.

Baker has said the legislation, based on recommendations of a special panel, “will make Massachusetts safer and improve how police officers train for detecting the influence of intoxicating substances like marijuana, how they interact with motorists who show signs of impairment, and eventually how these cases are tried in a courtroom.”

“There is plenty of evidence that no one should drive when they’re impaired, period, whether it’s alcohol or drugs of any kind,” he told reporters recently.

Baker’s plan also would extend the state’s open container law to include marijuana, prohibiting drivers from having loose or unsealed packages of pot in their vehicles.

Pot advocates and groups such as the American Civil Liberties Union of Massachusetts say they support efforts to reduce impaired driving but oppose pairing rules for drunken driving and marijuana use, citing the unreliability of marijuana field sobriety tests and the possibility that minorities could be targeted in impaired driving crackdowns, among other concerns.

“The problem is that these tests are not admissible in court,” said Borghesani. “Until we have a test that is scientifically proven to determine impairment, we shouldn’t be applying operating under the influence laws to marijuana.”

Sen. Jason Lewis, D-Winchester, has filed a separate proposal that would require cannabis regulators to set limits on the potency of marijuana products similar to beer, wine and hard cider.

Another proposal, filed by Rep. Jim O’Day, D-Worcester, seeks to increase the legal age for buying and using marijuana from 21 to 25.

Hensley, of the Marijuana Prevention Alliance, said there is increasing research showing negative mental health effects from use of the drug by youth and adults, including cannabis-induced psychosis.

“The harms of high potency cannabis use to mental health is becoming clear,” she said. “This should give everyone pause.”

There’s even a citizen-filed proposal seeking to repeal the recreational pot law, as well as one requesting the state Supreme Judicial Court to rule on the law’s constitutionality.

The 2016 voter-approved law allows adults age 21 and older to possess up to 10 ounces of weed, and it authorizes regulated cultivation and retail sales.

Since late November, nine retail marijuana stores have opened their doors -- including Alternative Therapies Group in Salem -- and regulators say they expect four to eight new stores each month.

Lawmakers revamped the law in 2017, requiring recreational marijuana sales to be charged a 10.75 percent tax on top of the state’s 6.25 percent sales tax. They also gave communities that allow retail sales the option of charging pot shops local excise taxes up to 3 percent.

Cities and towns can also charge impact fees that are “reasonably related to the costs” of hosting a pot business, don’t exceed 3 percent of the company’s gross revenue and expire after five years.

But pot advocates have complained that cities and towns are charging companies excessively. They’re backing bills that would restrict how much local governments can ask for, while giving state regulators more leverage over the host agreements.

“There are communities that are assessing fees on marijuana businesses that go well beyond the scope of the law,” Borghesani said. “We need to even the playing field.”

Christian M. Wade covers the Massachusetts Statehouse for North of Boston Media Group’s newspapers and websites.  

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