FILE - In this July 12, 2018 file photo, newly transplanted cannabis cuttings grow in soilless media in pots at Sira Naturals medical marijuana cultivation facility in Milford, Mass. Massachusetts marijuana regulators meet Thursday, Aug. 23 2018 to consider approving independent testing laboratories, which would clear the way to allow the first retail pot shops in state to open. (AP Photo/Steven Senne, File)
FILE - In this July 12, 2018 file photo, newly transplanted cannabis cuttings grow in soilless media in pots at Sira Naturals medical marijuana cultivation facility in Milford, Mass. Massachusetts marijuana regulators meet Thursday, Aug. 23 2018 to consider approving independent testing laboratories, which would clear the way to allow the first retail pot shops in state to open. (AP Photo/Steven Senne, File) Credit: Steven Senne

BOSTON — The first retail marijuana stores in the eastern United States moved a major step closer to opening on Thursday when Massachusetts regulators approved licenses for two independent testing labs.

The state’s voter-approved recreational marijuana law requires all cannabis products be tested for contaminants and the concentration of THC — the psychotropic chemical in marijuana — before they can be sold to consumers. The lack of any licensed labs had been among several factors delaying the rollout of retail sales which had originally been targeted to begin July 1.

The Cannabis Control Commission voted to license CDX Analytics, of Salem, and MCR Labs, of Framingham, pending final inspections and other conditions.

Both facilities already hold licenses from the Massachusetts Department of Public Health to test medical marijuana but were required to seek separate commercial licenses for the testing of recreational pot. They also needed to negotiate host community agreements with municipal officials.