Questions to Ask Your Cannabis Testing Laboratory Before You Sign

Most cannabis businesses choose a testing lab the way they choose most vendors: a phone call, a price quote, maybe a tour. But the questions you ask in that first conversation tell you far more than the price sheet does. Here are the ones worth asking directly, and what a strong answer sounds like.

"What is your accredited scope, specifically?"

Don't settle for "we're ISO accredited." Ask which panels — potency, pesticides, heavy metals, microbials, residual solvents, terpenes — are actually covered under their current accreditation. A lab can be accredited for some methods and not others, and that gap matters if you need a specific panel for a specific product category.

"What's your average turnaround time right now, and during your busiest month?"

Every lab has a fast answer for the first half of that question. The second half tells you whether you can actually plan around their timeline during harvest season or a big product launch.

"Walk me through your sampling protocol."

For flower, ask how they ensure a representative sample from the batch. For edibles, ask specifically about multi-point sampling — pulling from different locations across a production run rather than a single grab sample. A lab that can describe this in detail is one that takes result accuracy seriously before the sample even reaches an instrument.

"What happens if my batch fails?"

Ask them to walk you through the actual process: how you're notified, what data you receive, whether remediation and retesting are an option under current CRA rules, and how quickly a retest can be scheduled. A lab that treats this as routine, with a clear process, is more valuable to you long-term than one that's never had to explain it.

"Can I see a sample COA?"

Look at how clearly it's laid out. Are units consistent? Are pass/fail thresholds shown, or just a stamp? Could you hand this to a retail buyer or a state inspector without a follow-up call to the lab?

"Who will I actually talk to after I'm a client?"

Sales conversations are always responsive. Ask specifically who handles questions about a result six months from now, and what their typical response time is once you're not a prospective client anymore.

"How do you handle a result that's close to an action limit or label claim?"

This gets at how the lab thinks about measurement uncertainty — every result has some range around it, not a single perfect number. A lab that can talk you through how they treat borderline results is one that understands the science, not just the pass/fail stamp.

"What's your retention sample policy?"

Ask how long they hold leftover sample material and under what conditions, in case a retest or dispute comes up later.

The Real Test

None of these questions have a universally "correct" answer — different labs make different reasonable choices. What matters is whether they can answer clearly, specifically, and without hesitation. A lab that gets vague or defensive on any of these is telling you something worth paying attention to before you sign a contract, not after your first failed batch.

If you'd like to ask Prism Triangle these exact questions, get in touch with our team — we'd rather you ask now than find out the answers the hard way.

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This article is for general informational purposes. Always confirm current Michigan CRA requirements directly with the agency.