The state Department of Health has certified a second marijuana testing laboratory on Oahu.

Aeos Labs Inc., operated by Clinical Labs of Hawaii, got the green light Tuesday to begin testing medical cannabis from dispensaries, patients and caregivers.

“The certification of Aeos Labs provides more options for dispensaries to receive accurate and valid testing of medical cannabis,” Wanda Chang, DOH Environmental Health Analytic Services Branch chief, said in a news release. “This is a critical step in providing safe medical cannabis products for registered patients.”

Aeos Labs is the state’s third pot laboratory.

Steep Hill Hawaii on Oahu was the first to receive certification in July, while Pharmlabs Hawaii LLC on Maui was certified in October.

Hawaii legalized medical marijuana in 2000, but the state’s first dispensary, Maui Grown Therapies, only opened in August. Pono Life Maui also is selling cannabis on the island, while Aloha Green Apothecary and Noa Botanicals are currently operating on Oahu. A third Honolulu dispensary, Cure Oahu, is preparing to start marijuana sales as early as next week at 727 Kapahulu Ave. in the former Bank of Hawaii building.

Green Aloha on Kauai said on its website it is scheduled to open this month by appointment only. Two others, on Hawaii island, are projected to open by the summer, according to the Health Department, which issues roughly 1,500 medical marijuana cards each month. There were 20,518 cardholders as of Feb. 28.

Dispensaries are required to have their products tested for potency and purity before sale. The labs test for heavy metals such as arsenic, pesticides, solvents and microbial contaminants, as well as intestinal bacteria and pathogens and dangerous molds and toxins that can cause infection and disease.

Kauai and Hawaii island still do not have any labs that can test marijuana. However, Aeos Labs has offices on those islands to transport the products to Oahu, the DOH said. Labs can apply for state certification at health.hawaii.gov/statelab.