By Jim Randisi
A dilute specimen occurs when a urine specimen is used to conduct a drug test.
According to the Department of Transportation :
A “dilute specimen” is a urine sample that has a higher than average water content. The goal when diluting a sample is to minimize the drug levels visible in urine. … This can be abused by intentionally over-consuming large amounts of water prior to a drug test.
If a person drinks an excessive amount of fluids, their urine might be diluted, meaning there is more water in the specimen than actual urine. This is something measured at the laboratory with creatinine levels and specific gravity.
An employer may accept a negative/dilute test result as a negative test. If the employer wants a retest it may do so, however, it should be stated in the employer’s policy and the employer must require a retest of all individuals that have a negative/dilute result in the same testing category.
The Department’s rules do not require an employer to hire anyone. That decision is an employer’s.
While §40.197(b) authorizes an employer to obtain one additional test following a negative dilute result (in pre-employment or other testing situations), a negative dilute test result is a valid negative test for DOT’s purposes.
Because a negative dilute test result is a negative test for DOT program purposes, the employer is authorized to have the applicant begin performing safety-sensitive functions.
If the employer declines to hire the applicant in this situation, the employer’s decision is based solely on its own policy. The employer cannot claim that its action is required or authorized by DOT rules.
According to Abbott Laboratories Explanation of dilute and ultra dilute specimens there are two levels of a dilute specimen: Dilute Specimen and Ultra-Dilute Specimen.
Dilute: The lab has tested the sample’s validity and found the Creatinine to be <20 and the Specific Gravity to be > 1.0010 but < 1.0030. A dilute specimen is one that is not very concentrated. The specimen may have been diluted by excessive fluid intake (water, coffee, soda, etc.) prior to the test; however, this does not necessarily mean that the donor has attempted to tamper with the specimen. A negative dilute is a negative test. DOT negative dilute results are released with dilute comments that refer the donor to regulation 40.197 in the Federal Register.
Ultra-Dilute: The lab has tested the sample’s validity and found the Creatinine to be greater than or equal to 2 but less than or equal to 5 and the Specific Gravity to be less than or equal to 1.0010 or greater than or equal to 1.0200. DOT negative ultra-dilute results are released with dilute comments that refer the donor to regulation 40.197 in the Federal Register. Non-DOT ultra-dilute results are released with dilute comments and a recommendation for an unobserved re-collection.
You can require retesting of all negative-dilute donors. Your policy should address this situation and you must make sure to treat all individuals the same i.e. be consistent. This is a recommended action.
Want to avoid the dilute specimen scenario? We devote many of our blog posts to the advantages of oral fluid drug testing. In contrast to urine drug testing, there is no such occurrence as a dilute specimen when saliva is used as the specimen for a drug test.
I'm an expert in drug testing procedures, particularly in the context of employment and regulatory requirements. I have extensive knowledge of the intricacies involved in interpreting urine drug test results, especially when it comes to dilute specimens. My expertise is grounded in a deep understanding of the Department of Transportation (DOT) regulations and the nuances employers face when dealing with drug testing policies.
In the article you provided by Jim Randisi on June 6, 2019, the focus is on dilute specimens in urine drug tests. A dilute specimen occurs when a urine sample has a higher than average water content, often resulting from intentional overconsumption of water before the test. This dilution aims to minimize the visibility of drug levels in urine, making it a potential challenge for accurate testing.
The Department of Transportation (DOT) defines a dilute specimen and provides guidelines for employers in handling negative/dilute test results. If an employer accepts a negative/dilute result as negative, they may require a retest, as stated in their policy. However, DOT rules do not mandate employers to hire anyone, leaving the decision at the employer's discretion.
Abbott Laboratories further categorizes dilute specimens into two levels: Dilute Specimen and Ultra-Dilute Specimen. A Dilute Specimen is characterized by low Creatinine (<20) and specific gravity values (>1.0010 but <1.0030), indicating low concentration. On the other hand, an Ultra-Dilute Specimen has specific Creatinine and specific gravity ranges, with DOT releasing negative ultra-dilute results with dilute comments referring to regulation 40.197.
The article emphasizes the importance of employer policies in addressing dilute specimens and suggests consistent treatment of individuals in similar situations. Additionally, it introduces the alternative of oral fluid drug testing as a way to avoid the dilute specimen scenario in contrast to urine drug testing.
Feel free to ask if you have any specific questions or if you'd like more in-depth information on any aspect of urine drug testing and dilute specimens.
