How To Read A Certificate Of Analysis (COA)
If you’ve ever purchased CBD, there’s a good chance that you’ve seen a certificate of analysis before. Sometimes called COAs, certificates of analysis are technical documents that inform you about a CBD product’s potency and safety.
We can agree that knowing about your product is important, but sometimes, these documents can be hard to read. Hopefully, by the end of this post, you’ll know:
- What COAs are
- The shorthand abbreviations
- And how to read a certificate of analysis.
Note: For this post, we’ll examine parts of two older product COAs and an older Heavy Metal field test. You can find them in full in our Quality Test directory here.
What Is A Certificate Of Analysis?
A certificate of analysis is a technical document from an accredited third-party lab that can tell you about a product’s,
- Potency
- Presence of Terpenes
- Moisture Content
- Presence of any contaminants
- And more
The hemp and cannabis industries use COAs to confirm product potency and cannabinoid concentrations. Some companies, like Sunset Lake, also test their harvest lots for contaminants. In a few sections, we’ll examine what contaminants might be present in sungrown hemp flower.
Where Do You Get a Certificate of Analysis?
Most farms and vendors will get their COAs from third-party labs. Sunset Lake sends samples to a few different labs in the area. When you’re reading your certificate of analysis, always look for the lab that produced it. They should in no way be associated with the vendor or farm.
Why Is A Third Party Important?
Third-party testing is important because product quality should be impartial. For comparison, imagine that you’re buying a used car. Many of us aren’t mechanics so we rely on services like Carfax or our mechanic to tell us about any potential problems.
COAs are just like carfaxes. CBD vendors will probably tell the truth about their products, but for your peace of mind, you should see third-party tests to confirm. Many e-commerce vendors host their COAs on their websites. You may need a batch number to access the relevant product.
We list Sunset Lake’s COAs on a page called “Quality Tests,” which you can find here.
How To Read Your Certificate Of Analysis
On to the meat of this post. COAs are generally not user-friendly documents, so for the rest of this post, we’ll take you through the sections step-by-step.
Start At The Top
The header of your COA should contain information about tests, by whom, and when. Let’s dissect our 2022 Harvest Hemp Lot COA. (A harvest hemp lot is a sample of your plants from all around the field. The purpose is to discover any contaminants or heavy metals.)
Starting from the top left, we have,
- The Lab – The name of the lab that conducted the test will always be on a legitimate document. In our case, ProVerde Laboratories ran this test.
- Certificate ID – This is the ID number assigned by the lab for internal purposes. Sometimes hemp companies will reference this number, too.
- Client Sample ID & Lot Number – We provide the laboratory with the client sample ID and lot number. The sample ID tells us what we’re testing, and the lot number is associated with our hemp cultivation license.
- Matrix – This is the type of testing that the lab performed. For example, the lab tests smokable flower under the “dry flower” matrix and CBD gummies under their “edible” matrix. There is no one-size-fits-all CBD product potency test.
- Dates – Most COAs will have at least two dates listed on their documents. One date will note when the sample arrived, and a second to show when the product was tested. Sometimes COAs will have a third “expiration” date to tell vendors when their documents are no longer in compliance.
- Analyst – For the laboratory’s record keeping, this field denotes which laboratory technician carried out the testing on the product.
- Report/Certificate ID – This is the certificate’s unique identification number and should match the number on your product if provided on the label.
The Cannabinoid Profile
The cannabinoid profile is the real meat and potatoes of COAs. This section will tell us what cannabinoids are present in our sample and their respective concentrations. Below is the cannabinoid profile of our 2022 Hawaiian Hemp Flower (ID number: 110654)
Reading Our Cannabinoid Profile
You’ll notice first that we have three columns:
- ID – This is the cannabinoid in question
- Weight % – This number will tell us what percentage of our sample’s weight is that cannabinoid. The important one to look at in this column is the first, delta-9 THC. Cannabis flower is defined as hemp or marijuana based on this number.
- Concentration – This number tells us how many milligrams of each cannabinoid are in a gram of our sample.
How To Determine Total CBD
Smokables, like our 2022 Hawaiian Haze, are more often than not “raw” products. That means they’ll contain higher concentrations of acidic cannabinoids like CBDa.
Because smokables are more often than not “raw” products, they will contain higher concentrations of CBDa, CBD’s acidic precursor. CBDa turns into CBD via a process called decarboxylation, wherein it loses mass to become “activated” CBD.
To determine our product’s total CBD content, we have to convert the CBDa while also accounting for its lost mass. The equation looks like this.
([CBD] + [CBDa] x 0.877) = Total CBD
0.36 + (16.1 x 0.877) = 14.5% Total CBD
Accounting for the lost mass, this certificate of analysis says that after decarboxylation, our Hawaiian Haze flower contains 14.5% CBD.
Manufactured CBD Products
Reading the COAs of manufactured CBD products is similar to reading the COAs of our raw flower products. The above cannabinoid profile is from Sunset Lake’s 1500mg CBD Oil Tincture.
Our 1500mg CBD Oil Tincture contains 33.1mg of CBD and 16.6mg of CBDa per gram of oil. We’ll need to do a little back-of-the-napkin math to find the total number of milligrams contained in a single bottle.
Our carrier oil, MCT oil, weighs nearly 1 gram/mL. Our 1500mg CBD Oil Tincture contains 30 mL of CBD-infused oil, so let’s assume that our 30 mL of oil weighs 30 grams. We need to multiply 30 grams by our maximum CBD concentration (found at the bottom of the image) to find our total milligrams per bottle.
47.6mg/g x 30g = 1,428 mg Total CBD
While we undershoot the 1,500mg mark, the tincture is still within the allowable 10% (150mg) margin of error. These calculations will apply to most other oil, topical, and edible products, too.
Determining THC Content
You’ll also notice room for delta9-THC (Δ9 tetrahydrocannabinol) on most of your certificates of analysis. Delta9-THC is the only cannabinoid specifically restricted in the 2018 Farm Bill because of its psychoactive properties. According to the Farm Bill, cannabis is only considered to be hemp if the delta9-THC concentration is no higher than 0.3% of the sample by dry weight.
We see that while the total THC in our Hawaiian Haze is 0.51%, our delta9-THC concentration is only 0.05%, meaning that our flower is federally compliant.
Minor Cannabinoids
Depending on the depth of your certificate of analysis, you may also see other minor cannabinoids listed. Here’s what you might see:
- THCV (tetrahydrocannabivarin) – Similar to THC minus a few carbon chains.
- CBDV (cannabidivarin) – Similar to CBD in chemical makeup. Early studies suggest that CBDV could help with a number of maladies.
- CBG (cannabigerol) – A genetic precursor to both CBD and THC. Think of CBG as a cannabinoid stem cell.
- CBC (cannabichromene) – Considered one of the “big six” cannabinoids prominent in medical research. CBC isn’t intoxicating, but there is research into this phytocannabinoid’s medicinal benefits.
- CBN (cannabinol) – The “sleep cannabinoid.” As time passes, THC degrades into the non-intoxicating CBN.
- CBGa (cannabegeriolic acid) – The acidic form of CBG.
- D8-THC (Δ8 tetrahydrocannabinol) – Chemically different from D9-THC, but still intoxicating.
- exo-THC (exo-tetrahydrocannabinol) – Exo THC is an impurity formed during the synthesis of D9-THC.
Terpenes
Terpenes are aromatic hydrocarbons found in many plants and responsible for some of the various therapeutic properties of hemp.
Again, we look at our 2022 Hawaiian Haze Hemp Flower COA from ProVerde Laboratories. We see terpene concentrations visualized by a simple bar graph. Terpenes not in our sample are marked “ND” meaning non-detectable.
The most important column to look at here is the concentration (weight %). If you’re looking for hemp flower with a specific effects profile, be sure to look for terpene COAs.
Heavy Metals, Pesticides, & Fungi
Above are the pesticide and heavy metal results from Sunset Lake’s lot test. Some comprehensive COAs, called “full-panel” certificates of analysis, can include reports on heavy metals, fungi, residual pesticides, and residual solvents in manufactured products.
The main column to pay attention to is the “Status” column on the right. If you ever see a “fail” in this column, avoid that product.
Below is a list of handy definitions that you’ll want in order to understand these reports better:
- Conc. – Concentration.
- µg – Microgram (.000001 gram(s))
- kg – Kilogram (1000 grams)
- The “Limits” column is reported in µg/kg, which we can think of as parts per billion. These are the limits that are safe and acceptable according to the state of Massachusetts (where ProVerde is located)
- RL/LLD – Reporting limit/ lower limit of detection. These are usually specific to laboratories and or states where that lab is located.
- ND – Not detected to the lowest limit of detection.
Concentration
Conc (µg/kg) is going to tell us how many micrograms of that substance are in each kilogram of our product. In this particular case, the columns marked with “ND” means that none of said metal is detectable in the flower.
Reporting Limit
A reporting limit is the detection limit for a sample after making moisture content adjustments. In other words, the sample may have trace amounts of the substance being tested for, but because of instrument limitations, the test cannot detect them.
Status
This column tells us whether or not our product passes the test and is safe for consumption. In this case, we pass with flying colors.
Certificate Of Analysis Red Flags
You should consider each COA on its own merits, but there are a few instances when a COA (or lack of one) should make you pause.
You Didn’t Get A Certificate Of Analysis
Not getting a COA for your product is a red flag. Technically, every cultivator should test their flower, and every manufacturer should test their products. Without documentation, there’s no way for you to verify what’s in your product, quality, and safety.
Your Certificate Of Analysis Doesn’t Match Your Product
Does your product match the name of the product on your COA? How about the identification number? If not, that could be a problem.
Check the company’s website for the correct paperwork. If it’s not present, you could and should request the correct certificate of analysis before placing an order.
Your Certificate’s Measurements Are Off
There will be some times when your certificate of analysis’s concentrations and measurements may be off the mark when it comes to advertised CBD and THC levels. In some cases, that may be fine— the State of Vermont, for instance, allows for a 10% variance between testing and advertised CBD concentration. This is due in part to the sensitivity of the tools each lab uses and the variance between samples.
If your test results are off by more than 10%, then something may be wrong. It may be worth contacting your vendor about the accuracy of their COA.
Summary
Certificates of analysis aren’t the most user-friendly documents, but understanding how to read them will make you a decisive CBD consumer.
If you ever have any questions about our COAs, please reach out to us. If you’re looking for more information about COAs in general or on other companies’ COAs, we would be happy to help you out or provide you with more resources.
Updated
July 5, 2024