Negative Dilute Drug Test Result

It is important when discussing negative dilute drug test results to distinguish between regulated drug testing and non-regulated drug testing or NonDOT. Regulated drug testing is testing regulated by the United States Department of Transportation or DOT. Dilute drug tests are with urine drug screenings, not with hair or oral fluid drug screens.

In all cases when a drug test is reported as positive with dilution or positive dilute, it is always a positive drug test. A test result reported as a Negative Dilute is not a positive and should not be a violation of employer policy.

In this article regarding dilute drug test, we will cover:

Negative Dilute Drug Test Result – Confused, what does this mean?

Many times, employers get back a negative dilute drug test result and are often confused. What does it mean that the specimen is negative dilute? Check out the video on this page and read the below sections for your policy options.

The laboratory determines that a urine specimen is dilute based on testing for creatinine and specific gravity. Basically, the urine specimen has a higher water concentration than the average specimen. A negative dilute specimen, by definition, is a urine specimen that tests negative and has a creatinine of greater than 5 mg/dl or less than 20 g/dl and a specific gravity is less than 1.0010 (or greater than 1.0200). Creatinine is a waste product that is consistent in normal human urine. A urine specific gravity test compares the density of urine with the density of water. These two tests are routinely performed on every urine sample that is evaluated at the Lab.

What Causes the Negative Dilute Drug Test Result?

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

When the lab reports a specimen as dilute, there are certain levels of creatinine and specific gravity that determine that the specimen may be dilute. This means that the donor consumed a larger quantity of water before providing the urine specimen. This may be normal as many folks drink a lot of water for health reasons or because of a fear of not being able to urinate at the time of the drug test specimen collection. This may be abnormal as perhaps the donor is drinking an excessive quantity of water in an attempt to cheat on the drug test. So, there is a little bit of a “gray” area concerning specimens that are reported as dilute specimens.

First and foremost, if the report from your Medical Review Officer is Positive Dilute, the result is Positive and the company should follow policy for the Positive result. The indication that the specimen was dilute may be interesting, but it is not relevant to the handling of the positive test result.

Consequences of Negative Dilute Drug Test Result

If you get a final result from the medical review officer (MRO) that says Negative Dilute, you have two options. You should choose one of these two for your drug free workplace policy and stay consistent. This is a DOT requirement and a best practice for NonDOT testing.

  1. Accept the negative dilute result as is, or
  2. Require the employee retest upon immediate notification


Note: A negative dilute is not a violation, it is a negative drug test result.

There should be no violation consequences for a negative dilute drug test result. It is a negative result but could potentially be suspicious because of the amount of water in the urine.

Handling DOT Negative Dilutes

For negative dilute results, the first question is whether or not the testing program is a regulated program – Federal employees or DOT drug testing. If it is a regulated testing program the following guidelines apply:

In the regulated drug testing program negative dilutes are managed in one of two ways depending on the creatinine levels.

When specimens have creatinine levels of greater than or equal to 2 mg/dl but less than 5 mg/dl; Specific Gravity less than or equal to 1.0010 the medical review officer (MRO) will report the results as dilute specimen with a requirement that the donor go for a second collection under direct observation.

When specimens have creatinine levels of 5 mg/dl or greater but less than 20 mg/dl and specific gravity is greater than 1.0010 and less than 1.0030, and these specimens test negative; this is a negative dilute and the employer should have a policy on how to manage this situation. The MRO drug test result report will simply state Negative Dilute. The policy should either be to accept the result as is or to have the donor go for a second collection. DOT rules (49 CFR Part 40.197) allow the employer to make a decision to re-collect these donors one time under the following circumstances:

a) There is a policy statement in place before the fact that allows the practice.

b) All employees need to be treated equally.

c) The re-collections are not to be observed re-collections.

d) Only one re-collection is allowed, and the result of the second collection is the result of record, even if it is another negative, dilute.

e) The decision to re-collect may vary by reason for test. In other words, an employer may decide to re-collect all pre-employment dilute negatives, but not random dilutes, or vice versa.

Sample policy language for regulated (DOT) drug testing programs can be found in the section below.

Handling Non-DOT Negative Dilutes

The above guidelines for negative dilute drug test results can also be used for non-DOT programs, this is a best practice. Your Company drug free workplace policy could specific different options. In no situation should a negative dilute drug test result be considered a violation of company policy.

In non-regulated drug testing programs, the decision on how to handle the Negative Dilute drug test is an employer decision. It is highly recommended that a policy is developed in advance on how to handle these results. Sample policy language for non-regulated or Non-DOT drug testing programs can be found in the section below.

A dilute specimen, by definition, is a urine specimen that has a creatinine of greater than 5 mg/dl or less than 20 g/dl and a specific gravity is less than 1.0010 (or greater than 1.0200). These two tests are routinely performed on every urine sample that is evaluated at the Lab. If the specimen meets the above 2 criteria, it is reported as a “Dilute specimen”. When a urine specimen is “dilute,” it is possible that drugs in their system may not be 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.

As with DOT testing, there is a highly suspicious level of dilution which would be where the creatinine levels are greater than or equal to 2 mg/dl but less than 5 mg/dl; Specific Gravity less than or equal to 1.0010 the medical review officer (MRO) will report the results as negative dilute with a recommendation that the donor go for a second collection under direct observation. It is not recommended that a non-regulated employer require direct observed collections unless there is a significant concern for safety relative to the tested group.

National Drug Screening recommends for negative dilute specimens for non-regulated employers to require for both applicants and employees a second collection with little advance notice and instructions to not drink an unusually large quantity of fluids before the testing. For applicants, the second test would determine eligibility for employment and should be negative, not negative dilute. For employees, a supervisor should escort the employee to the test to ensure that large quantities of fluids are not consumed.

DOT Policy Language Recommendations

DILUTE SPECIMEN

If the MRO informs the Company that a negative test was dilute, the Company may take the following action depending on Company policy and/or guidance provided by the MRO:

(1) If the MRO directs that a recollection take place under direct observation (i.e., because the creatinine concentration of the specimen was equal to or greater than 2mg/dL, but less than or equal to 5 mg/dL), the Company will do so immediately. Failure of the employee or applicant to submit for this recollection is classified by the DOT as a refusal to test.

(2) Otherwise (i.e., if the creatinine concentration of the negative dilute specimen is greater than 5 mg/dL and less then 20mg/dl ), the Company will for existing employees:

(3) Regarding a negative dilute (greater than 5 mg/dL on an applicant, the Company will:

NOTE: The Company will treat all employees the same for this purpose. The Company may, however, establish different policies for different types of tests (e.g., conduct retests in pre-employment situations, but not in random test situations). The Company will inform its employees in advance of its decisions on these matters.

When such a retest is required after a negative dilute specimen, the employee or applicant will be given the minimum possible advance notice that he or she must go to the collection site. Instructions will be provided on how to avoid a dilute specimen. The result of the retest will be considered the final result, not the result from the first test. For current employees required to submit to a return-to-duty test or follow-up test (both of which under DOT regulations must render a negative test result) a second directly observed collection resulting in a negative dilute urine test result will render the final result a “negative” test; and an applicant with a second directly observed negative dilute urine test result will not be eligible for hire under the Company’s uniformly enforced policy.

If the employee declines to take a retest required because of a dilute specimen, the action will be considered a “refusal to be tested” and will be treated the same as a confirmed and verified positive result. The offer of employment will be rescinded if an applicant refuses to take the retest because of a dilute specimen.

Non-DOT Policy Language Recommendations


DILUTE SPECIMEN

There is some flexibility for non-DOT programs, below find our recommendations.

If the MRO informs the Company that a negative test was dilute, the Company may take the following action depending on Company policy and/or guidance provided by the MRO:

(1) If the MRO directs that a recollection take place (i.e., because the creatinine concentration of the specimen was equal to or greater than 2mg/dL, but less than or equal to 5 mg/dL), the Company will do so immediately. Failure of the employee or applicant to submit for this recollection is classified as a refusal to test.

(2) Otherwise (i.e., if the creatinine concentration of the negative dilute specimen is greater than 5 mg/dL and less then 20mg/dl), the Company will for existing employees:

(3)    Regarding a negative dilute (greater than 5 mg/dL on an applicant, the Company will:

NOTE: The Company will treat all employees the same for this purpose. The Company may, however, establish different policies for different types of tests or employee categories (e.g., conduct retests in pre-employment situations, but not in random test situations). The Company will inform its employees in advance of its decisions on these matters.

When a retest is required after a negative dilute specimen, the employee or applicant will be given the minimum possible advance notice that he or she must go to the collection site. Instructions will be provided on how to avoid a dilute specimen. The result of the retest will be considered the final result, not the result from the first test.

If an employee declines to take a retest required because of a dilute specimen, the action will be considered a “refusal to be tested” and will be treated the same as a confirmed and verified positive result. The offer of employment will be rescinded if an applicant refuses to take the retest because of a dilute specimen.

How to Avoid a Dilute Specimen

Employers should give employees or applicants the least possible advance notice of a urine drug test. Advice employees and applicants to not drink unusual amounts of liquids before arriving for testing or while waiting to be called for testing. Individuals should consume their normal intake of fluids prior to a drug test. Those that typically do not typically drink a lot of fluids and believe they may have difficulty providing a urine specimen should drink not more than one extra glass of water. Check out our blog page – Avoiding Negative Dilute Drug Test Results

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