ND (non-detect)

Non-detect is a lab result, not a statement that a compound is absent. It means the method, at its validated limit of detection, saw no signal distinguishable from a blank. A different method with a lower limit could find the same compound in the same sample.

On hemp certificates of analysis, ND usually appears on the delta-9 THC and THCa lines of isolate and broad-spectrum products. Some labs write less than LOQ instead, which is a slightly weaker statement: the compound might have been seen but could not be measured. The report should say which convention it uses and print the limit.

ND became a compliance term with section 781. The amended federal hemp definition excludes finished hemp-derived cannabinoid products holding more than 0.4 mg total THC per innermost container, effective December 11, 2026 (7 U.S.C. 1639o; P.L. 119-103). For a product at the lab's detection limit, total THC in the container is at most the limit times the container mass. If that product is under 0.4 mg, ND proves compliance. If it is not, ND proves nothing and a lower-limit method is needed.

Accredited labs validate their detection limits under ISO/IEC 17025 (ISO). THC-free as a marketing phrase should always be backed by ND on a current batch COA with the limit shown.