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What are Drug Test Cut Off Levels?

An important factor that must be considered when carrying out drug testing is the application of cut-off levels. All drug screens have a cut off level which is internationally decided by by SAMHSA (Substance Abuse and Mental Health Services Administration). In this article we look at the Drug Test Cut Off Levels for various commonly used drugs of abuse.

How Are Drug Test Cut Off Levels Shown?

Drug testing cut-off levels are normally expressed as ng/mL (which means nanograms per millilitre) The cut-off level of a drug test is the ng/mL measurement at which a sample is deemed to be either a positive or a negative test result.

Each drug of abuse has it’s own defined drug concentration level which is the cut-off that has been chosen to minimise the chance of false positive results. An important thing to note here is that a negative drug test result does not necessarily mean that the urine sample is drug free, it just means that the concentration of the drug is lower than the defined cut-off.

When a drug test result proves to be positive, this is only an indicator that drug is present in the sample. What the test cannot tell you is how much of the drug was used or taken and if this had any correlation with the impairment of the individual at the time. It should also be remembered, that this kind of test is a screening tool and another testing method should be used to obtain a definite positive result.

Drug Test Cut Off Level For Cannabis

We have a dedicated article on the Drug Test Cut Off Levels For Cannabis, which is an informative read if you need more info on the subject. You may also want to read our blog post on how long cannabis is detectable in the body.

In general, the cut off levels for Cannabis are as follows:
Urine Drug Testing – 50 ng/mL
Saliva Drug Testing – 12 ng/mL
UK Drug Testing Cut Off for Driving  – 2µg/L

drug test cut off levels THC

Drug Test Cut Off Levels for Cocaine

Please refer to our article on Drug Test Cut-off Levels for Cocaine for detailed information on this subject. You should be aware that a urine drug test for cocaine will detect both Cocaine and its metabolite benzoylecgonine. How long cocaine is detectable in the body will be determined by past usage and the type of drug test taken.

In general, the cut off levels for Cocaine are as follows:
Urine Drug Testing – 300 ng/mL
Saliva Drug Testing – 20 ng/mL
UK Drug Testing Cut Off for Driving – 10µg/L

Drug Test Cut Off Levels for Opiates

An opiates drug test will screen for a variety of substances, which include Heroin and Morphine. Our blog post can offer you more information on Drug Test Cut Off Levels for Opiates. You may also refer to our article on how long heroin is detectable in the body?

In general, the cut off levels for Opiates are as follows:
Urine Drug Testing – 300 ng/mL
Saliva Drug Testing – 40 ng/mL
UK Drug Testing Cut Off for Driving – 5µg/L

Drug Test Cut Off Levels for Benzodiazepines

Benzodiazepines are part of a group of drugs known as depressants. Clonazepam, Diazepam, Flunitrazepam, Oxazepam, Rohypnol and Temazepam will all be picked up by a benzodiazepines drug test.

Detail information on drug test cut off levels for benzodiazepines can be found in our blog post. Similarly, if you require information on how long benzodiazepines can stay in your system.

In general, the cut off levels for Benzos are as follows:
Urine Drug Testing – 300 ng/mL
Saliva Drug Testing – 10 ng/mL
UK Drug Testing Cut Off for Driving – 50µg/L


This post has been updated since its original publication in 2014.
Photo by Louis Reed on Unsplash
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