DENVER — Washington marijuana business owners are urging regulators to require cultivators to test adult-use crops for pesticides, a move that has triggered alarm bells among smaller growers.

Some cultivators hope such a move — already adopted in other states — would inspire confidence among consumers and bolster recreational marijuana sales.

But smaller growers — already squeezed by falling prices — worry they wouldn’t be able to afford mandatory pesticide testing, which is estimated to cost up to $300 per test.

The move also could force small farmers to cultivate fewer strains to keep costs down, although regulators so far have not signaled they will require the testing.

“Fundamentally, requiring pesticide testing doesn’t bother me,” said Mark Greenshields, a cannabis grower in Seattle, “but technically, increasing the costs, that’s a problem.”

Regulators already conduct random pesticide checks. But a mandatory regimen would force growers to submit cannabis for pesticide testing along with the standard testing criteria the state already requires.

Steve Fuhr, a producer-processor in Seattle, said “numerous industry groups,” including the Washington CannaBusiness Association and the Cannabis Alliance, have met and approached the state’s Liquor and Cannabis Board and provided written suggestions that the agency adopt mandatory pesticide testing that follows other cannabis markets in the United States.

Fuhr said his interest in mandatory pesticide testing arose from hearing that cannabis testing labs in the state have found “troubling reports” of pesticide content when conducting blind tests of flower.

“We feel that it’s a public safety issue and for the image of the industry,” he said.

Other states

Washington would join other states, including Oregon, California and Colorado, in requiring cultivators to submit product for pesticide testing for recreational cannabis.

“We shouldn’t have this great reputation of some of the best weed in the world and not back it up with scientific testing,” said Shawn DeNae, CEO of Washington Bud Company in Smokey Point.

However, a Liquor and Cannabis Board spokesman said the state is not pursuing implementing mandatory pesticide testing at this time.

Washington has a little more than 1,000 licensed producer-processors.

Currently, the state requires adult-use cannabis producers to test for:

• Potency, including THC and CBD levels.

• Microbials, which are microorganisms including mold, fungus and bacteria.

• Mycotoxins, which are byproducts of the metabolism of certain species of mold and fungus.

• Water activity, which measures shelf stability to determine how likely the product will develop problems such as mold and fungus.

The business opportunities for testing labs could be on the upswing if state regulators decide to make pesticide testing mandatory for all cannabis.

Molecular Testing Labs in Vancouver, is authorized to conduct the full range of testing for both recreational and medical cannabis. Stuart Bennett, director of sales for the lab, said adding pesticides would add about $250-$300 per test.

“It would certainly increase our overall business if it is mandated,” he added. “For every 50 recreational tests we do, we do one pesticide.”

Added costs

From an operational standpoint, the addition of mandatory testing wouldn’t change much for Greenshields because his cultivation facility uses predatory insects to control pests rather than pesticides.

But he is concerned about the added cost. When the state added mycotoxins to the list of required tests last year, his lab bill went from $60 to $105 per test, he said.

“I imagine throwing a mandatory test on there is not going to be cheap,” he added.

At Washington Bud Company, adult-use marijuana is voluntarily tested for pesticides and heavy metals.

DeNae recently wrote a check to her lab for $2,800 to test less than 25 pounds.

“The extra money that it takes to pesticide and heavy metal test is certainly a hit,” she said. “It’s a commitment, and it takes a lot longer to go through the process.”

Washington Bud Company periodically tests enough of its crop to prove its cannabis is clean. The company charges a premium. An eighth of an ounce of retail indoor-grown flower sells for $40-$45.

Some outdoor-grown ounces of flower are selling for not much more than that in retail stores.

DeNae believes mandatory pesticide testing will be a good development for the state’s market and help eliminate growers that use chemicals on their plants. But it also might drive some growers out of business.

“A lot of people have cut their margins down so short they wouldn’t be able to survive the tests,” she said. “That’s a downfall of people not understanding what their bottom line is.”

Extraction testing

Confidence Analytics, a cannabis testing lab in Redmond, charges up to $250 per lot to test for pesticides and heavy metals.

Shannon Stevens, the lab’s quality assurance manager, said she hasn’t seen much pesticide testing commissioned by growers since the recreational market supplanted the medical program. The bulk of the pesticide testing at her lab is from extractors who want to make concentrates.

“Since so many of the chemical residues will be concentrated along with the cannabinoids in that process,” she said, “they want to make sure they’re buying clean material before they potentially contaminate their extraction system.

“Obviously, if they create a product that would fail the state standards for residues, they’re expected to destroy it.”

DeNae would also like to see products for vaping and concentrates undergo mandatory testing.

“If they’re using dirty bulk products and it concentrates in their extracts, then that’s even worse,” she said. “Extraction doesn’t remove pesticides, it concentrates pesticides.”

Limited strains

One noticeable impact that mandatory testing could have on small growers is a reduction in the variety of strains they grow.

If the lot sizes stay the same, where one test accounts for five pounds of cannabis per strain, and the costs increase by adding pesticide tests, then growers likely will grow fewer strains with higher plant counts to cut down on cost.

“It would shift us to grow larger amounts of less varieties,” said Matt Sampson, owner of North Coast Growers in Anacortes.

Sampson has heard discussion of state regulators increasing the testing lot size to 15 pounds, which could help keep costs down.

Said DeNae: “No matter if you grow a crop that’s 2 pounds or 20 pounds per strain, it’s the same test with the same cost. So pesticide and heavy metal testing is more cost effective for growers who grow large quantities.”