It’s the second meeting in a row canceled by the commission, following a July 3 meeting that was called off because too many commission members would have been absent. The commission has met once, on June 13.

The group, a requirement of the state marijuana law, was slow to form. The law was in place last summer but Cannabis Control Commission Executive Director Shawn Collins, chairman of the commission by statute, said in March some appointments to the commission had still not been made.

The 13-member commission was tasked by the Legislature with producing “a comprehensive study relative to the regulation and testing of operating under the influence of marijuana, narcotic drugs and depressant or stimulant substances” as well as recommendations for legislation by Jan. 1, 2019.

In late June, the Department of Public Health said about 21 percent of adults in Massachusetts reported using marijuana in the last 30 days and a third of users said they have driven under the influence of marijuana in the last 30 days. The commission said it will announce its next planned meeting date later.