What is a negative dilute drug test result?


Perhaps the donor drinks a lot of water, perhaps the donor is trying to cheat the test. 

We define a dilute specimen dilute consistent with SAMHSA guidance and DOT published regulations:

(a) As a laboratory, you must consider the primary specimen to be dilute when:

(1) The creatinine concentration is greater than or equal to 2 mg/dL but less than 20 mg/dL, and

(2) The specific gravity is greater than 1.0010 but less than 1.0030 on a single aliquot.

If the specimen meets the above 2 criteria, it is reported as a “Dilute  specimen”. When a urine specimen is “dilute” and negative, it is possible that drugs in their system may not have been detected. We recommend that an employer have a section in their drug testing policy stating that  another specimen be collected as soon as possible with minimum advance notice, this will help  prevent false negative results. However, the employer may also elect to accept the negative results with the notation “dilute” from the lab. The company policy should be consistent in all  cases. See sample language for company policy.  

Policy Option For Non DOT Programs: 

Option 1: If the urine specimen is determined to be negative and diluted, require a second test and advise applicant or employee to refrain from drinking excessive amounts of fluids.  Be sure to provide minimum possible advance notice for this second collection. The second test shall become the test of record.  For existing employees, a company official may escort the employee to the collection site. 

Option 2: A negative dilute result will be accepted for compliance with this policy. (This would be the appropriate action if the company policy does not address dilute specimens.)