When you apply for a job and you are asked to pass a drug test the consequences of failing the drug test are pretty simple: you don’t get the job.  When you are required to pass a drug test for probation the consequences are much more severe: usually it is jail time.

A pre employment urine drug screen has a standard set of cut off levels for each substance.  A cutoff level is the minimum concentration of drugs or drug metabolites present in the specimen before the lab will reach a determination that the sample is positive for a certain drug.  Each drug has a different cutoff level. For marijuana that cut off level would be fifty nanograms per milliliter.  For cocaine it would be one hundred and fifty nanograms per milliliter and so on for different drugs.  These cutoff levels are pretty much universally accepted and anything below these levels would be a negative result on the test.

Probationary drug tests have a whole different set of criteria.  The cut off levels for substances for someone on probation vary from jurisdiction to jurisdiction and substance to substance.  Most of the time there will be a zero tolerance for all substances.  Some jurisdictions may have a cutoff level of twenty nanograms or fifteen nanograms for THC.  There will be some jurisdictions that will fail the person being tested if the creatine level or specific gravity in the sample is too low.  This is what is known as a diluted sample and the courts may take this as an attempt to tamper with the results of the test and fail the person.