Week 33: Understanding Certificates of Analysis (COAs)

A Certificate of Analysis (COA) is a document from an independent laboratory verifying what's actually in a cannabis product. COAs are essential for confirming that products contain what labels claim and are free from harmful contaminants.

Learning to find and interpret COAs is one of the most valuable skills for navigating the cannabis marketplace.

What Is a COA?

A COA is a third-party laboratory report containing:

Cannabinoid testing. Verification of cannabinoid types and amounts in the product.

Contaminant screening. Tests for pesticides, heavy metals, residual solvents, microbial contamination, and other potentially harmful substances.

Sample identification. Information about what product was tested, batch numbers, and test dates.

Laboratory information. Details about the testing lab, including accreditation.

Pass/fail determinations. Whether the product meets quality thresholds.

COAs provide independent verification rather than relying solely on company claims.

Why COAs Matter

COAs serve several important functions:

Label verification. Does the product contain what the label claims? COAs answer this question definitively.

Safety assurance. Testing confirms products are free from contaminants that could cause harm.

Legal compliance. COAs verify THC levels are within legal limits for hemp products.

Quality indicator. Companies willing to invest in testing and share results demonstrate quality commitment.

Consumer empowerment. COAs give you data to make informed decisions rather than trusting marketing alone.

In an inconsistently regulated market, COAs are your best source of objective product information.

How to Find COAs

Accessing product COAs:

QR codes. Many products include QR codes on packaging that link directly to lab results.

Company websites. Look for "lab results," "COA," or "test results" sections. Some sites let you search by batch number.

Direct requests. Contact customer service if COAs aren't readily available. Quality companies provide them promptly.

Point of purchase. Some retailers can provide COAs for products they sell.

If you cannot find or obtain a COA, that's a significant red flag about product quality and transparency.

Reading Cannabinoid Results

The cannabinoid section shows what's in the product:

Cannabinoid breakdown. Lists each cannabinoid detected (CBD, THC, CBG, CBN, etc.) and its amount.

Units of measurement. Usually expressed as mg/g (milligrams per gram), percentage, or mg/mL.

Total cannabinoids. Sum of all detected cannabinoids.

THC content. Particularly important for legal compliance. Total THC should be ≤0.3% for legal hemp products.

ND (Not Detected). Indicates a cannabinoid was below detection limits—effectively absent.

LOQ (Limit of Quantification). The smallest amount the lab can measure accurately.

Compare lab results to label claims. They should match closely.

Reading Contaminant Screening

Safety testing covers multiple categories:

Pesticides. Tests for common agricultural chemicals. Results should show all tested pesticides as "Pass," "ND," or below action limits.

Heavy metals. Screens for lead, mercury, arsenic, cadmium, and other toxic metals. All should be below established limits.

Residual solvents. For extracted products, tests confirm extraction solvents were removed. Particularly important for concentrates.

Microbial testing. Screens for mold, bacteria, and other microorganisms. Contamination can cause illness.

Mycotoxins. Tests for toxic compounds produced by certain molds.

All contaminant categories should pass. Any failures indicate product safety concerns.

What to Look For

When reviewing COAs, check:

Match between product and COA. Does the batch number match? Is this COA actually for the product you're evaluating?

Recent testing date. COAs should be reasonably recent—within the past year for most products.

Accredited laboratory. Look for ISO accreditation or state licensing indicating the lab meets quality standards.

Complete testing. Both cannabinoid and contaminant screening should be included.

Label accuracy. Cannabinoid amounts should match label claims within acceptable variance (typically ±10-15%).

Passing results. All contaminant tests should pass or show levels below action limits.

Thorough review catches problems that casual glances might miss.

Red Flags in COAs

Warning signs include:

Missing information. Incomplete COAs lacking key sections raise questions.

Old test dates. Very old COAs may not represent current production.

Significant label discrepancies. Large differences between label claims and lab results indicate quality control problems.

Failed tests. Any failed contaminant test is a serious concern.

Unknown or unaccredited labs. Labs without recognized accreditation may not follow proper testing protocols.

Altered documents. Signs of manipulation or editing suggest dishonesty.

Any red flags warrant caution about the product.

COA Limitations

Understand what COAs can and cannot tell you:

What they verify. The specific batch tested contains what results show.

What they don't guarantee. That every batch is identical, that the product will work for your purposes, or that the company maintains consistent quality.

Sample representation. COAs represent the sample sent to the lab. Reputable companies test representative samples; less scrupulous ones might test only their best batches.

Testing methods vary. Different labs may produce slightly different results using different methods.

COAs are valuable tools but not complete guarantees. Use them alongside other quality indicators.

Key Takeaways

• COAs are third-party lab documents verifying cannabinoid content and safety
• Find COAs via QR codes, company websites, or direct requests
• Cannabinoid results should match label claims closely
• All contaminant tests should pass or show levels below action limits
• Verify batch numbers, test dates, and lab accreditation
• Red flags include missing information, old dates, failed tests, and label discrepancies

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