How to read a certificate of analysis: total THC, THCA and the numbers that decide legality
Published Sep 18, 2026
Page updated Oct 9, 2026
A certificate of analysis (COA) is the lab report for one batch of a product. Retailers and consumers now read it for one number above all others.
The rows that matter
- Delta-9 THC (% by weight) — the historic hemp test: 0.3% or less by dry weight.
- THCA (% by weight) — the acid form in raw flower. It becomes delta-9 when heated.
- Total THC — delta-9 plus 0.877 × THCA. Texas, Tennessee, Florida and others use this test today; federal law uses it from December 11, 2026. High-THCA flower typically shows 15–25% total THC — far above 0.3%.
- mg per serving / mg per container — for finished products. Federally, final hemp products are capped at 0.4 mg total THC per container from December 11, 2026; states set their own serving caps (Georgia 10 mg, Tennessee 15 mg, Minnesota 5 mg, New Mexico 2 mg…).
- Other cannabinoids listed — delta-8, delta-10, HHC, THC-O, THCP. Which bucket each falls into decides whether the November 12 or the December 11 date applies. HHC is already Schedule I (May 4, 2026).
- Lab name and test date — a COA older than the batch, or from a lab with no accreditation, is a red flag.
Compare the COA with the state's caps
The checker shows each state row's caps. Compare the COA's numbers with them yourself. The checker never decides whether one product is legal — the lamp comes from the rules row.
Choosing a lab
USDA published a directory of DEA-registered hemp testing laboratories; its address gave a "404 - Not Found" page on October 9, 2026. USDA's page for hemp testing laboratories (read October 9, 2026) says that USDA "is delaying until December 31, 2026, the enforcement of a requirement that all hemp must be tested by a Drug Enforcement Agency (DEA)-registered laboratory". Accreditation to ISO/IEC 17025 with a cannabinoid scope is the mark to ask for; the accreditation bodies (A2LA, ANAB, PJLA) keep public certificate searches. The testing labs directory on this site is seeded from archived copies of the USDA directory and shows accreditation once verified against a certificate.
General information — not legal advice. Checked October 8, 2026.
Sources
- P.L. 119-37 §781 — total tetrahydrocannabinols including THCA; 0.4 mg per container — checked Oct 8, 2026
- Texas 25 TAC §300.101 — total delta-9 = delta-9 + 0.877 × THCA — checked Oct 8, 2026
- USDA AMS — Information for Hemp Testing Laboratories (enforcement of the DEA-registered laboratory requirement delayed until December 31, 2026) — checked Oct 9, 2026
Frequently asked questions
›What is total THC?
Delta-9 THC plus 0.877 × THCA (the fraction of THCA that becomes delta-9 when heated). Several states use it today; federal law uses it from December 11, 2026.
›Which lab should I use?
A lab accredited to ISO/IEC 17025 with a cannabinoid scope. USDA published a directory of DEA-registered hemp testing laboratories; its address gave a '404 - Not Found' page on October 9, 2026. This site's lab directory is seeded from archived copies of that directory and shows accreditation once verified.
This site provides general information from public sources with the statute and the check date on every row. It is not legal advice, and it never states that a product is legal without the state, the date and the source.