Nick Brown, left, owner of Colorado marijuana shop High Country Healing in Silverthorne, looks over containers of marijuana while employee James Gilbert helps customers on Jan. 6, 2015. (Helen H. Richardson, Denver Post file)

If Massachusetts legalizes pot, what can be learned from Colorado?

BOSTON — Massachusetts may not be prepared for public health and safety issues associated with the potential legalization of recreational marijuana, a special state Senate committee that recently visited Colorado warned Tuesday.

In a 118-page report, the panel recommended steps that could be taken should voters approve a likely November ballot question that would allow the recreational use and possession of up to an ounce of marijuana for those 21 and older.

The report suggested that taxes proposed in the ballot initiative would not cover the cost of implementing a recreational marijuana law and warned that a black market for pot would persist in the state even if the drug was sold legally at retail outlets.

Representatives of Campaign to Regulate Marijuana Like Alcohol, the group behind the proposed ballot question, said the committee made a number of false claims in its report.

In January, members of the panel spent several days in Colorado, which was the first U.S. state to regulate recreational marijuana sales.

Here are some things to know about the report from the Special Senate Committee on Marijuana.

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Pro or con?

The committee took no official stance on Massachusetts marijuana legalization for recreational use, but the tone of the report and comments made during a Statehouse news conference suggested that senators were skeptical of the ballot question — and some were outright opposed. The panel’s chairman, Democratic Sen. Jason Lewis, of Winchester, downplayed public opinion polls showing strong support for legalization, saying it was too early to predict what voters might do in November.

Higher taxes

The proposal would create a 3.75 percent state excise tax on retail marijuana sales to be assessed on top of the state’s 6.25 percent sales tax. Cities and towns would also have the option of imposing an additional sales tax up to 2 percent on marijuana sales. Such a tax structure would not be enough to cover the regulatory and social costs of legalized marijuana, the report said. It suggested a marijuana sales tax of between 10 percent and 20 percent, a local option tax of up to 5 percent, and an excise tax on marijuana growers of between 5 and 15 percent. Jim Borghesani, a spokesman for the group sponsoring the ballot initiative, argued the current tax plan not only would cover regulatory costs, but provide additional revenue for other state needs.

Homegrown fears

Allowing Massachusetts residents to legally grow pot in their homes could provide consumers with greater choice, and be helpful to those who do not live near retail outlets, the committee said. But marijuana cultivated at home, the senators said, can’t be tested for safety or potency and could be more easily diverted to the black market. So they suggested a ban or temporary moratorium on homegrown pot, or alternatively a requirement that growers register with the state. The proposed ballot question would allow cultivation of up to 12 plants and 12 seedlings per household.

Restricting edibles

Edible forms of marijuana, such as cookies or candy, are the fastest growing segment of the marijuana market in Colorado and now comprise half the state’s legal pot sales, the report found. The senators called for prohibitions on the sale of products that could be mistakenly eaten by children, such as candy bars or gummy bears, and safeguards against the spraying of THC on existing food products.

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Online: Senate’s Massachusetts Marijuana Report