Dilute Specimens

A “dilute specimen” test result can create misunderstandings, even lost job opportunities, but it
may not be catastrophic. Numerous, legitimate reasons can cause a urine specimen to be “dilute,”
meaning not every dilute specimen indicates a deliberate attempt at adulteration or sabotage.

In fact, the DOT recognizes three tiers of dilute specimens, and only one is treated as conclusive
proof of adulteration. Test results in the second and third tiers, despite the opinions of some
inexperienced Human Resources practitioners, should not be the reason for lost job opportunities.

Tier 1:
• < 2 mg of creatinine/dL of urine
• This is a “positive dilute” and is considered a positive drug test

Tier 2:
• ≥ 2 and ≤ 5 mg/dL
• While not considered a positive drug test, this will cause the Medical Review Officer to order a
second test under direct observation

Tier 3:
• > 5 and < 20 mg/dL
• This is a “negative dilute” and the employer can choose whether to require a second test or just
accept this result and move on
• Specimens in this range commonly result from donors simply drinking a lot of fluids, so the U.S.
Coast Guard is not concerned with these Tier 3 test results

Once again, test results in Tier 2 and Tier 3 should not be the reason for lost job opportunities.
If you believe you have been unfairly denied opportunities as the result of one of these dilute
specimen test results, contact us at SSMP and maybe we can help.