COA Glossary

This COA glossary explains the most common terms you will see on a cannabis/hemp lab report, with a focus on THC-free CBD products. If you’ve scanned a product QR code or downloaded a PDF and want to understand what the numbers and acronyms mean, start here.

A Certificate of Analysis (COA) helps verify potency (how much CBD, THC, and other compounds are present) and safety (screens for contaminants like heavy metals, pesticides, and microbes). Knowing the basics lets you compare products and confirm a THC-free claim.

To go deeper into broader topics, see our Glossary & Learning Center. For compound-specific definitions, please use our Cannabinoid Glossary, Terpene Glossary, and THC & Testing Glossary.

Disclaimer: This page is informational only and is not medical, legal, or testing advice. Product performance and test results can vary by batch and lab method. Drug-testing outcomes cannot be guaranteed.

What is a Certificate of Analysis (COA)?

A COA is a third-party laboratory report that documents a product’s potency and safety test results. It typically includes the sample identity (batch/lot), methods used, measured cannabinoids, and compliance with action limits for contaminants.

For THC-free CBD, the key objective is confirming that delta-9 THC and total THC are non-detect (ND) or below method limits, while CBD content aligns with the label.

How to read a COA at a glance

Verify identity: Match product name, batch/lot number, and form (oil, gummy, capsule, topical).
Scan potency: Confirm CBD content and check delta-9 THC and total THC are ND or below limits.
Check method limits: Note LOD/LOQ for THC to understand the smallest amount the lab can detect/quantify.
Review safety panels: Pesticides, residual solvents, heavy metals, microbes/mycotoxins show Pass/Fail.
Confirm lab quality: Look for ISO/IEC 17025 accreditation, report date, signatures, and a QR code link.

Key COA terms (glossary)

Potency and cannabinoid reporting

Cannabinoids: Active compounds in hemp/cannabis (e.g., CBD, d9-THC). For definitions of specific cannabinoids, see our Cannabinoid Glossary.
Delta-9 THC (d9-THC): The primary intoxicating THC isomer measured for legal compliance.
THCa: Acidic precursor to THC; converts to d9-THC when heated (decarboxylation).
Total THC: Calculated to estimate THC after decarboxylation, typically d9-THC + (THCa × 0.877).
CBD (cannabidiol): Non-intoxicating cannabinoid commonly reported as mg per serving and mg/g or %.
CBDa: Acidic precursor to CBD; converts to CBD when heated.
Total CBD: Often CBD + (CBDa × 0.877), reflecting post-decarboxylation potential.
Minor cannabinoids: Compounds like CBG, CBC, CBN. Listed if measured; see Cannabinoid Glossary for details.
Terpenes: Aromatic compounds sometimes reported on separate panels; see Terpene Glossary.
ND (Non-detect): Below the lab’s detection limit; not necessarily zero.
LOD (Limit of Detection): Smallest amount the method can reliably detect as present.
LOQ (Limit of Quantitation): Smallest amount the method can measure with acceptable accuracy/precision; higher than LOD.
Action limit: Regulatory or manufacturer threshold for Pass/Fail decisions.
Serving calculation: Per-serving potency derived from batch concentration and serving size.

Safety and contaminant panels

Pesticides: Agricultural chemicals; COAs list compounds tested and whether each passes set limits.
Residual solvents: Leftover solvents from extraction (e.g., ethanol, butane); reported in ppm with limits.
Heavy metals: Elements like lead (Pb), arsenic (As), cadmium (Cd), mercury (Hg); typically in µg/g (ppm).
Microbial screening: Total aerobic count, yeast and mold, bile-tolerant gram-negative bacteria; often Pass/Fail.
Pathogens: Specific microbes such as Salmonella and Shiga-toxin E. coli; must be absent for compliance.
Mycotoxins: Toxins from molds (e.g., aflatoxins, ochratoxin A); reported vs. strict limits.
Foreign matter/filth: Non-product material; relevant for raw plant material.
Water activity (aw): Indicator of microbial growth potential; lower values reduce spoilage risk.
Moisture content: Percent water by weight; affects stability and microbial risk.

Methods, units, and calculations

HPLC/UPLC: Liquid chromatography methods commonly used for cannabinoids (no heat; preserves acids).
GC-MS/LC-MS/MS: Gas/liquid chromatography with mass spectrometry for sensitive analyses.
ICP-MS: Mass spectrometry used for metals testing.
qPCR: Molecular method to detect specific microbial DNA.
Units: % (w/w), mg/g, mg/mL, mg/serving, ppm (mg/kg), ppb (µg/kg), µg/g; note the matrix (oil, gummy, flower).
Decarboxylation factor: 0.877 multiplier converting acidic forms (THCa, CBDa) to neutral equivalents.
Measurement uncertainty (MU): Estimated range around a reported value reflecting method variability.
Recovery/spike: Accuracy check by adding a known amount of analyte and measuring percent recovered.
Duplicate/RPD: Precision check via repeat measurement; RPD is relative percent difference.
Calibration curve/R²: Verifies instrument response linearity across concentrations.
Dilution factor: Sample dilution applied; important for back-calculating true concentration.

Report metadata and verification

Batch/Lot number: Unique identifier for the production run; should match product packaging.
Sample ID/COA ID: Lab-specific identifier for tracking the sample/report.
Sample matrix: Product type (tincture, gummy, capsule, topical, flower, distillate).
Collected/Received dates: When the sample was taken and when the lab received it.
Report date/Revision: When the COA was issued and if it has been updated.
ISO/IEC 17025: Lab accreditation standard demonstrating validated methods and quality systems.
Chain of custody (COC): Documentation of sample transfer from producer to lab.
Analyst/Reviewer signatures: Indicate approval by qualified personnel.
QR code/Verification link: Directs to the lab’s hosted report for authenticity.
Pass/Fail statement: Overall compliance status for each panel vs. action limits.
Method/SOP reference: Identifies the analytical procedure used.

THC-free context and drug testing

On a COA, “THC-free” typically means delta-9 THC and total THC are ND or below the method’s LOQ. Because ND depends on method sensitivity, “THC-free” does not mean absolute zero. Some drug tests can detect trace THC or related metabolites, and individual metabolism varies. If avoiding THC is critical, review LOQ values, confirm total THC is ND, and consider broad-spectrum or isolate products. Outcomes on workplace or clinical drug tests cannot be guaranteed.

Verifying authenticity

Use the QR code or direct lab link to view the hosted COA.
Match the batch/lot on your product to the COA.
Check for ISO/IEC 17025 accreditation and a recent report date.
Look for consistent units, method references, and complete panels.
Contact the brand or lab if any detail seems inconsistent.

Related resources

Glossary & Learning Center: Broader terms and guidance.
Cannabinoid Glossary: Compound-by-compound definitions.
Terpene Glossary: Aroma and effect descriptors.
THC & Testing Glossary: Legal thresholds and test methods.

FAQ

What does ND mean on a COA?
ND (non-detect) means the analyte is below the method’s detection limit. It does not prove the absolute absence of the compound.

What’s the difference between LOD and LOQ?
LOD is the smallest amount the method can detect as present; LOQ is the smallest amount it can measure accurately and precisely.

Why is total THC higher than delta-9 THC?
Total THC includes potential THC from THCa after decarboxylation: d9-THC + (THCa × 0.877).

How often should COAs be updated?
Each batch should have its own COA. Check that the lot number on the product matches the COA you’re viewing.

Does THC-free guarantee passing a drug test?
No. Even with ND results, testing methods and individual factors vary. No product can guarantee a specific drug-testing outcome.

Explore rigorously tested options: Shop THC-free products at cannagea.com/thc-free.

Summary

A COA verifies potency and safety through standardized lab methods. For THC-free CBD, confirm ND or below-LOQ results for delta-9 THC and total THC, review safety panels, and verify accreditation and batch details. Use this glossary to interpret key terms, and consult the linked resources for deeper topic-specific learning.