The state Department of Health expects to certify Hawaii’s first medical marijuana testing laboratory by the end of the month.

At least three of the state’s first eight dispensaries have marijuana ready to sell but can’t open until the DOH certifies laboratories — PharmLabs Hawaii, Clinical Laboratories of Hawaii and Steep Hill Labs — to test the potency and purity of the drugs.

Keith Ridley, head of the dispensary program at the DOH, told a legislative oversight committee Wednesday that the department must ensure the safety of the products before they are sold to patients.

“We have seen reports where products haven’t been tested and there have been serious negative consequences,” he said. “We want to make sure … patients can be safe.”

Sen. Will Espero (D, Ewa Beach-Iroquois Point) said he is concerned the department may be over-regulating and causing unnecessary delays.

“I understand we need to set standards but if you’re expecting the Hawaii program to do more over and beyond what’s happening on the mainland, literally tens of thousands of dollars are being lost because of our bureaucratic slowness,” he said.

Medical marijuana was legalized in Hawaii in 2000, but patients have no legal way to obtain the drug. As of June 30, there were 17,591 registered patients, up 573 from the month before.