PLENNY LEARN · LAB REPORT LITERACY
What “not detected” actually tells you
ND usually means “not detected” on a cannabis certificate of analysis, or COA. It means the laboratory did not detect the named substance at its stated detection or reporting threshold. It does not prove that the concentration is exactly zero.
By Plenny · Updated September 18, 2026 · 4 minute read
What does ND mean on a cannabis COA?
Start with the report’s legend. Laboratories define their abbreviations and reporting conventions there. Keep the result attached to its compound name, units and stated limit.
The EPA’s data-quality guidance distinguishes a nondetect from a measured zero: when a concentration falls below the detection limit, its exact value is unknown. That analytical principle helps explain an ND entry, although this EPA document concerns environmental data rather than cannabis rules.
An ND result for one cannabinoid also says nothing about an untested cannabinoid. Read the list of substances actually included in the panel. Do not turn a single row into a claim about every chemical in the sample.
What is the difference between LOD and LOQ?
Limit of detection: the lower concentration at which a laboratory can reliably distinguish a signal from background.
Limit of quantitation: the lower concentration at which the method can reliably report a numerical amount.
Below the quantitation limit. Follow the laboratory’s legend to determine exactly how it uses this label.
SC Labs explains its LOD and LOQ definitions and reports concentrations between those two limits as “<LOQ.” That is an example of a laboratory’s reporting practice, not a reason to assume every COA uses identical conventions.
Look for the limits on the same row or in the method notes. Published SC Labs panel details show that limits vary by analyte and sample type. One sensitivity number does not describe every substance the laboratory tests.
A worked example: ND, <LOQ and a number
Teaching example only: a method has an LOD of 0.02 mg/g and an LOQ of 0.10 mg/g for a fictional analyte. Its legend defines ND as below LOD and <LOQ as detected below the quantitation limit.
These invented values explain the labels. They are not legal limits, a real batch report or a statement about product safety.
The result is ND. What can I conclude?
The method did not detect the analyte at the stated 0.02 mg/g threshold. Do not replace ND with a claim of exactly 0.000 mg/g.
The result is <LOQ. Is that the same as ND?
Under this example’s legend, no. The analyte was detected, but its amount was below 0.10 mg/g, the lower quantitation limit. The label alone does not supply a reliable exact concentration.
The result is 0.15 mg/g. What changed?
The report now provides a numerical concentration above the example’s LOQ. Whether it meets a specification is a separate question that requires the relevant action limit and decision rule.
Keep the units consistent. A number in mg/g cannot be compared directly with a percentage or a number in micrograms per gram. For mass concentrations, 1 mg/g equals 0.1% and 1,000 micrograms per gram.
Does ND mean a cannabis product passed?
ND describes an analytical result. Pass or fail describes how a result compares with a particular specification. Those are different pieces of information.
ACS Laboratory’s COA guide separates potency results from contaminant results and their action levels. A measured amount can be below an applicable limit without being ND. Equally, an ND label without the relevant reporting threshold is incomplete context for evaluating compliance.
Read the laboratory’s reported outcome for each required category. A cannabinoid panel does not substitute for pesticide, heavy-metal or microbial testing. A result on a product COA also cannot predict the outcome of a person’s drug test.
Before relying on an ND result
SC Labs’ COA walkthrough identifies sample details, dates, verification links and detailed test pages. Use those parts of the report together.
If a row is blank, absent or marked with an unfamiliar code, ask the laboratory what it means. Do not silently translate missing information into “not detected.”
Common questions
Does ND mean no THC at all?
No. Check which THC compound was tested and the threshold attached to the result. An ND entry does not establish an exact zero or describe untested compounds.
Can I compare ND results from two laboratories?
Compare the analyte, units, sample type, method and reporting thresholds first. The same letters can represent results obtained at different sensitivities.
Is not tested the same as not detected?
No. A test that was not performed supplies no detection result. Use the laboratory’s legend for codes such as NT, and ask about any missing panel.
Keep learning
Sources and scope
Sources checked September 18, 2026. Laboratory resources describe their own reporting practices. The EPA reference supports the general distinction between nondetection and zero; it does not set cannabis requirements. This guide explains report terminology and does not certify a sample or establish a legal threshold.
Chris Garcia, Owner and CEO
September 18, 2026
How this page is prepared: Plenny uses linked research and other relevant sources for educational explanations, and product details and batch COAs where relevant. General strain, flavor, and effect descriptions are not guarantees.
Commercial transparency: Plenny sells products discussed on this website. Educational pages are not medical or legal advice, and content is not medically reviewed unless a named licensed reviewer is shown.