Inside The Company Making Sure Your Pot Is Strong (And Safe)

As legalized marijuana becomes more prevalent, it’s becoming more important to hold it to the same quality and safety standards that we use for anything else we put in our bodies. Take a trip inside medical cannabis testing company CW Analytical, which tests weed for potency and contamination.

Inside The Company Making Sure Your Pot Is Strong (And Safe)
Cannabis via Shutterstock

Dr. Robert Martin, the co-founder of medical cannabis testing company CW Analytical, is a 30-year veteran of the food industry. In the 1990s, he was part of the Kraft Foods team that helped create the Nutrition Labeling and Education Act, which gave the FDA the right to require nutrition labeling on most foods. After his stint at Kraft, Martin worked as director of research and development at Dreyer’s Ice Cream. He knows more than most people the value of quality assurance and labeling. So after retiring in 2002, Martin moved onto another industry that he believed was in dire need of some quality assurance: marijuana.


Martin spent the first part of his retirement working as a consultant. Then he noticed that some of his friends were starting to get sick with late-stage cancers as they aged. “My friends were coming to me and asking me questions about marijuana. The reason they were asking me is because I’ve used marijuana a lot through my career and life and I don’t take any pains in telling anyone that, really,” he says.

When his friends started asking about safety, Martin visited dispensaries in California (CW Analytical is based in Oakland and has an outpost in San Francisco), talked to people in the industry, and ultimately found that few people were paying attention to quality assurance. “Most people were concerned with, how strong is it? There weren’t that many labs, and the ones that were operating were focused on cannabinoids [a measure of potency]. I thought there was a big need for a new dispensary and a new lab.”

Martin’s dispensary never got off the ground, but the lab did. Founded in 2009 by Martin and an environmental chemist named John Oram, CW Analytical is one of a select group of labs focusing on marijuana safety in addition to potency. The six-person team focuses on microbiological safety (bacterial testing, mold tests, E.coli test, etc.), truth in labeling, tamper evidency, and dosage–with a heavy focus on microbiological safety.

Why test marijuana?

We expect our food to be free of contamination. When something happens–a salmonella outbreak or an E.coli scare–there are recalls. Food gets taken off the shelves, and news outlets frantically report the story. Martin strongly believes that marijuana users should have those same protections (perhaps minus the outraged news stories, which wouldn’t help the already fragile industry). He cites California’s Sherman Food, Drug, and Cosmetic Law of 2008 as evidence: “You have a right as a consumer to know what you’re ingesting in terms of caloric impact, in terms of allergenic impact. I mean, these are very serious things we’re talking about,” he says.

The unfortunate truth is that even legal, regulated marijuana has a contamination problem–not surprising considering that most California dispensaries aren’t required to test their goods for safety (some cities, including Oakland and Richmond, do require testing).


When Martin first opened his lab, he assumed that pesticides were going to be the main contamination issue. It’s a logical assumption. As with fruits and vegetables, growers sometimes spray pesticides on their cannabis. He didn’t think microbiological safety would be a problem, mainly because of substances on the surface of the plant–called terpenoids–that tend to be anti-bacterial. He was wrong.

In the food industry, approximately 80% of all contamination involves handling issues, according to Martin. He believes that’s true in the marijuana industry as well, where most contamination is the result of poor handling, poor hygiene, improper storage, and lack of cleaning instruments. “Essentially, we’ve changed our opinion. Now we look at a flower of marijuana like a little sticky gooey sponge and if you roll that through dirt, it’ll pick up that dirt,” he says.

CW Analytical has a poster up on its office wall featuring some of the unsettling facts: 12% of cannabis flowers contain high levels of molds or other fungi. 70% of bubble hash contains high levels of bacteria. Most of this contamination isn’t severe enough to hurt marijuana users, but some of it could be. “Someone’s going to get real sick if they haven’t already,” says Martin.

Who Goes To A Marijuana Testing Lab?

With so many data points on contamination floating around, you might think that dispensaries and growers would be jumping at the chance to prove that their marijuana is clean. They’re not. “As it is right now, only about 15% of people are testing,” says Martin. CW Analytics’ quandary is figuring out how to spread the message about quality assurance without damaging the industry. It shouldn’t, of course–contamination is not inherent to marijuana any more than it’s inherent to food. There just isn’t as much oversight as in the food sector.

The lab tries to make testing as cheap as possible without bankrupting itself; dispensaries already deal with enough roadblocks that pricey lab testing could scare them away. “We have these three things we try to follow: affordability, speed, and accuracy,” says Martin. “We changed our business plan at CW to involve our vendors, to make sure we get good discounts on our supplies, to involve our team on efficiency, and to work every minute we can to become efficient.” That is, he points out, why there’s nobody in the lab on the morning of my visit. Samples don’t begin arriving until 1 PM.


Even so, the lab’s customer base is unstable. If you live in Northern California, it’s hard to ignore the nearly constant stream of news reports about landlords being pressured to kick out dispensaries, either because they’re too close to parks and schools, or simply because the local U.S. Attorney decides she doesn’t like them.

Martin explains: “Clients get nervous sometimes and they just quit doing business. That just happens. Last month, we had a regular client just disappear and we wondered what happened. We found out later that he was nervous and couldn’t take the stress and anxiety of the federal pressure any longer. And that’s a shame. He really cared about what he was doing, and he was a good producer.”

Dispensaries that work with CW Analytical bring in samples of their marijuana for testing, and if they get unsatisfactory results, often decline to work with the grower that provided the tainted sample. It’s great for patients who go to these diligent dispensaries–but growers will sometimes just go to other dispensaries that don’t require testing. On the flip side, CW Analytical is more than willing to help growers figure out what they can be doing differently. The growers just need to care enough to change, and without mandatory testing, many don’t.

Inside the Lab

Walking into the CW Analytical lab, you’d never know that all the vials, beakers and drawers are filled with marijuana. The lab, which looks pretty standard from an outsider’s point of view, doesn’t smell at all. As Martin walked me through the space, I got to see exactly how samples are put through the wringer.

Every new sample makes a stop at the intake area, where lab workers fill out chain of custody form so that if law enforcement comes in, they at least have some evidence to show that they are legally in possession of the marijuana. All sorts of products come through–edibles, flowers, hash, concentrates–and everything is treated differently. Over the years, the lab has come up with various standards for how to prepare the items.


Each item gets a unique sample ID number, and each number is held in a virtual database. Once the items have been processed, clients can log onto the CW Analytical website and look at their results. There are no standards for contamination in cannabis, so the company uses food industry standards.

Once the samples make it past the intake area, they’re separated and tested. “Depending on what it is, it gets treated differently. It gets put into methanol usually for cannabinoid testing, acetone for pesticides, so whatever the chemists do to it here they set it up in different ways,” explains Martin.

Martin takes me over to the area set up for cannabinoid preparation, where there are shakers and sonication baths to break up the plant material so that it releases cannabinoids into a solution. A moisture analyzer reveals how much moisture the samples have been exposed to–something that goes into the cannabinoid calculation, since the chemists measure based on dry weight.

The chemists are set up for microbiology testing as well. Each sample is put into a little buffer, and all of the resulting liquid is shot onto a petri film. All of the films are kept at body temperature, and every two days Martin and his colleagues check for bacteria. Martin shows me some of the samples that been heating up; there are only small dots of bacteria growing on the films. “There’s lots that’s clean today,” he notes.

For fungal testing, little fungal plates are placed in an old oven-like USDA incubator. The samples are kept at ambient temperature (the fungi grow at a higher rate that way).


Yet another area contains the machines used to analyze cannabinoids and pesticides. Samples are analyzed for cannabinoids with a gas chromatograph machine with flame ionization detector (FID) that separates them out by molecular weight. Eventually, the molecules are burned and measured against a standard to calculate cannabinoid contents.

A gas chromatography–mass spectrometry (GC-MS) machine tests for pesticides by breaking samples down into molecules and throwing them against an electron plate. The plate shatters the molecules so that the machine can look at the fragments. “The computer gives probabilities of what we’re looking at. You’ve got to look at the data and you’ve got to have a chemist there to interpret the data,” explains Martin.

In short: it takes a lot of work to get the data that dispensaries are looking for, and it’s not cheap (still, the lab can process hundreds of samples each day). “We’re fighting every day to keep the costs down for [our clients],” says Martin.

What Next?

For whatever reason, San Francisco has been slow to catch on to testing. Martin is hopeful that will change. And while Washington and Colorado–the two states where voters last year opted to make marijuana fully legalized–haven’t announced any quality assurance standards, CW Analytical was invited along with other California labs to discuss possible regulations with the Washington Liquor Control Board. California is leading the way in cannabis testing; the Association of California Cannabis Laboratories (ACCL) has eight members listed on its website, including The Werc Shop in Los Angeles and Steep Hill Halent Laboratories, also located in Oakland.

There is a real opportunity for these states to set an example–to make it so obvious that quality assurance testing is necessary that no one would dare neglect to do it. Mandatory testing could ultimately make the entire industry seem more legitimate. “The industry doesn’t help itself,” says Martin. “We put terrible faces out in public and people believe there are a lot of stoners running everything, and that’s not really the case anymore.”

About the author

Ariel Schwartz is a Senior Editor at Co.Exist. She has contributed to SF Weekly, Popular Science, Inhabitat, Greenbiz, NBC Bay Area, GOOD Magazine and more