Non Detect Definition

What is the current definition for Non Detect for THC? I’ve heard anything below .1% is typically non detectable. However, in a recent conversation, I was told true Non Detect is .0001 or less. We are developing a new remediation process whereby THC will be less than .0245. I was under the impression that few, if any, labs could detect THC at that level. If anyone has any insight to share, it would be greatly appreciated. Thanks!

it’s not that they cant detect it. just that they don’t usually bother.

looking harder costs more money. so if you’re selling thousands of potency tests, you adjust your detection level to a point where you see what you need to accurately, and let the LOD fall where it may.

the machinery itself is capable of parts per billion, so the only thing that is going to make the THC undetectable is the huge CBD peak next door.

other relevant threads…


If you can quantitate 0.0005%, then you know apriori that others can detect it

If you cant quantitate 0.0005% then you need to reduce the number of significant digits to reflect that.

LOQ = 0.005%?

Then you should present your lower limit as 0.02%

Anything else is spurious precision

The detection limit by either GC or HPLC depends on how strong of an extract you make.
If you put 100milligrams of hemp in the extraction vial you will have half the the detection limit that you would have if you put 200mg in the vial instead. So why not put 1 entire gram or 10 grams or more in the vial to push the detection limit down as far as you want. Its because if you also want to measure the CBD at the same time and in the same analysis you can’t put so much hemp in the vial that the CBD peak is so big you can’t measure it. So its a compromise. Make the extract strong enough to measure the THC but not so strong you can’t measure the CBD.
Typically with GC you can measure .01% THC and still measure 10-15% CBD. That’s a 1000 to 1 ratio.
Hugh Goldsmith


As Hugh said you can always decrease your dilution to increase the peak size. This would essentially give you the ability to detect at a much lower level, this would be targeted at one compound, similar to how some labs do a “trace level test” This is always an added cost and us usually the price of a regular potency test. sometimes the labs will charge more because they may need make a new sample a couple times to find the right dilution to give an accurate result.

Non detectable THC is a term that is missing a very important side note, and that side note would be ND down to (whatever the labs stated LOD)

With that in mind ND THC can range drastically. I’m seeing some people state they need less than 1ppm of THC so %0.001.

We just had a trace test done on our “tfree” distillate and it came back at a solid 0.009%


I could be mistaken, but I believe 1ppm is the same as .0001%.


yes, this is absolutely correct, I missed a zero.

thanks for clarifying.

We usually use 0.08% as pre discussed level for ND products. We have had no push back from large public companies at this level once we had our discussion explaining there is no standard definition for ND.

1 Like