A lack of testing facilities is threatening to slow the rollout of legalized recreational marijuana sales in Maine.

Maine voters approved adult use marijuana in a 2016 vote, and state regulators have said products could be available in stores in spring 2020. The state is requiring marijuana products to be tested for factors such as potency, foreign materials, dangerous molds and harmful microbes.

But only one lab was in the pipeline for state approval to serve as a testing facility as of Friday. The state is hopeful more applicants will come forward, but officials also acknowledge that the lack of applicants could slow down retail sales.

The sole company to apply to serve as a testing facility, Nelson Analytical of Kennebunk, likely can’t handle the volume of testing on its own, said Lorri Maling, the company’s laboratory director. Handling testing for facilities in far away parts of New England’s largest, most rural state could also be difficult, she said.

“There’s going to be a bottleneck. We really need more laboratories. Maine’s a huge state,” Mailing said. “Hopefully there are some labs that are going to open up north as well.”

The lack of labs is the latest hiccup in Maine’s long drive toward legal marijuana sales. The state began accepting applications from prospective marijuana retail, manufacturing, cultivating and testing facilities in early December and received 76 applications in the first week. None were from testing facilities, though Nelson Analytical has since submitted.

The possibility of delay due to few labs is “certainly a possibility, but one of which we are keenly aware and committed to addressing,” said David Heidrich, a spokesman for the Maine Office of Marijuana Policy. Maine has learned from other states that it takes time for high quality labs to establish themselves and develop the capacity to keep up with the volume of product in a newly legal state, he said.

“While testing is critical, it is equally important that testing be done right,” Heidrich said.

Other facilities are looking to get involved in testing but have yet to submit applications. Greg Newland, chief scientific officer of Nova Analytic Labs in Portland, said his company is readying an application.

It’s tough to know how many labs are needed, Newland said. Heidrich said the state would prefer to have more than one.

“Without a proper testing facility or program, the safety of the product could be in jeopardy,” Newland said. “It’s dangerous to put out a product for consumption if it isn’t tested for heavy metals and dangerous chemicals.”