Massachusetts voters could be seeing double on the November ballot when it comes to the question of whether to legalize recreational marijuana, if Senate President Stanley Rosenberg has his way.

Rosenberg hopes to get a second question on the Nov. 8 ballot about whether the state should legalize marijuana — to clean up what he says would be the messiness of trying to change a proposed ballot question that would legalize the drug for those 21 and older and allow retail sales beginning in January 2018.

“I’m very concerned,” said the Amherst Democrat, following the report of a nine-member Senate committee that researched the experience of legalizing the drug in Colorado and Washington state.

Their 120-page report, issued March 8, described policy concerns in those states that were either not included in the legislation proposed in the ballot question or would have been dealt with differently than what the experience in those states would call for, Rosenberg told Recorder editors recently.

Unlike House Speaker Robert DeLeo, Gov. Charlie Baker, Attorney General Maura Healey and Boston Mayor Marty Walsh, Rosenberg has not said he is against the ballot question sponsored by the Campaign to Regulate Marijuana Like Alcohol.

But the “blueprint for policy work” if the ballot measure is approved by voters, or if the Legislature chooses to deal with the issue otherwise, points to a variety of public health and public safety concerns, Rosenberg said. Those include long-term developmental impacts because of marijuana use by young people who use “too much too soon,” and the lack of effective tests to know how much intoxification causes driver impairment.

“One of the most shocking things” that task force members found was “very potent PHC (Tetrahydrocannabinol) content in drinkables, edibles and even wearables” that can be rubbed or sprayed on the skin, or eaten as candy.

“The fact that people can access it who shouldn’t … if someone forgets and leaves the gummy bears on a table, and then Johnny comes along and grabs a snack … but these aren’t your ordinary gummy bears.”

Also, he said, Colorado and Washington have found that legalization has not reduced the black market for marijuana.

Rosenberg said he has been trying to convince the governor and House speaker that passage of the ballot measure — on which a recent Suffolk University-Boston Globe poll found voters about evenly split — would leave the Legislature trying to amend the proposed legislation, stirring a hornets’ nest. An easier solution, Rosenberg said, would be for the Legislature to propose its own ballot question, giving lawmakers an opportunity to craft a bill that addresses everyone’s concerns.

“It’s never been done,” he said of lawmakers voting to put proposed legislation on the ballot. Doing so would not be prohibited under the state Constitution, he said, and could be done right until the time the secretary of state needs to print up ballots.

The response Rosenberg said he’s gotten from Baker and DeLeo is essentially, “we’ll deal with it when voters speak,” meaning that they would have to tinker with the language of the proposed legislation.

But he added, “Once the voters vote a question in, the proponents fight tooth and nail to ensure it is not undermined in intent, and they often fight to maintain it in most or all its detail. So we’re going to have quite a time if the ballot question passes and we come in and try to fix it.”

Making changes on matters the ballot measure does not address would not necessarily be that difficult, but the rest could be problematic,  he added.

“Given that ballot questions are written from the perspective of one constituency, one point of view … there are lot of things where you really should have the kind of deliberative process that a legislature engages in to come up with best answers, rather than having people reinforcing each others’ beliefs.”

In the event both questions were approved by voters, Rosenberg said legislators could choose to amend either.

“The Legislature always has the power to amend a law,” he said, unless it’s part of the Constitution.

The marijuana ballot campaign has until July 6 to file 10,792 additional signatures with the secretary of state’s office, having already collected 103 signatures in an earlier part of the campaign, according to its website.

On the Web: 1.usa.gov/1VUxejf
www.regulatemassachusetts.org