A cutoff level is the concentration at or above which a laboratory reports a result as positive rather than negative. It is a threshold somebody chose, not a natural boundary, and understanding that explains both why results are reported as they are and why the answer to a dilute specimen is a recollection rather than a decision.
What a cutoff level is for
Every analytical method can detect vanishingly small quantities, so without a threshold almost any specimen would report something. Cutoff levels exist to separate meaningful use from trace amounts and incidental exposure, and to give confirmatory testing a defensible line. Federal testing sets specific levels for both the initial screen and the confirmation, and those levels are the product of a long regulatory process. A non-regulated employer may set its own, and most are best served adopting the federal levels precisely because they are defensible and universally understood.
Lower is not automatically better
Employers sometimes ask for lower cutoffs on the theory that they will catch more. They will, and much of what they catch will need explaining: more non-negatives, more confirmatory tests, more Medical Review Officer reviews, more delay and more results where the honest answer is that a small quantity was detected and it means very little. Unless you have a specific safety rationale for a lower threshold and the MRO capacity to handle the consequences, the standard levels are the better buy.
What a negative dilute actually means
A dilute result means the creatinine concentration and specific gravity indicate the specimen contained more water than normal. It says nothing directly about drug use. It can result from deliberate flushing, and equally from somebody drinking a lot of water because they were nervous about producing a specimen or because it was a hot day. The standard response is a recollection, sometimes with instructions on fluid intake beforehand, and under the federal procedure a negative dilute is reported as a negative test with the dilute finding noted. Treating a negative dilute as a positive or as a refusal is a serious mistake.
Reading a result properly
Negative means nothing above the cutoff. Negative dilute means the same with an unusually watery specimen. Positive means confirmed above the confirmation cutoff and reviewed by a Medical Review Officer. Adulterated and substituted are separate findings handled as refusals under the federal procedure. Cancelled means a problem with the specimen or the process meant no result could be reported. Each of those has a different correct response, and a policy that only addresses positive and negative leaves the person making the decision without an answer for the ones that actually cause trouble.
Questions people ask about pre employment drug screen cutoff levels
What is a drug test cutoff level?
The concentration at or above which a result is reported as positive. It is a chosen threshold that separates meaningful use from trace amounts and incidental exposure, and it gives confirmation a defensible line.
What does negative dilute mean?
The specimen contained more water than normal, indicated by creatinine and specific gravity readings. It says nothing directly about drug use, and the standard response is a recollection rather than a decision.
Should I ask for lower cutoff levels?
Usually not. Lower thresholds produce more non-negatives needing confirmation and Medical Review Officer review, more delay, and more results that mean very little. The federal levels are defensible and well understood.
Is a dilute result a refusal?
No. Adulterated and substituted specimens are treated as refusals under the federal procedure; a dilute one is not. A negative dilute is reported as a negative test with the dilute finding noted.