Pros and Cons of Various Drug Testing Specimens

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What is the preferred specimen (urine, saliva, hair) for use in a workplace drug testing program? Unfortunately, there is no clear-cut answer.

The choice depends on a variety of factors including: federal regulations, a company’s level of risk tolerance, desired detection length, costs, and the type of testing required – (pre-employment, random, reasonable suspicion, post-accident or return-to-duty screening).

Each specimen offers particular strengths and weakness and the use of multiple specimens in testing programs can often complement each other.

In the beginning there was urine

In the late 1980’s and early 1990’s, private employers started implementing drug-free workplace programs and urine was considered the “gold standard” in testing.

It was easy to collect and transport, inexpensive to test, accurate, provided a detection window deemed adequate by many employers, and at that time was difficult to subvert.

However, testing rates from drug screening programs initiated during the late 80’s showed double digit positive rates falling dramatically over time to current single digit numbers.

Quest Diagnostics –

Artificially low positivity rates

While urine positivity rates have decreased over time to around a three percent level, suspicion amongst drug screening professionals is that the positive rates on drug screens have become artificially low which may demonstrate that a persistent population of illicit drug users have discovered ways to sidestep or subvert drug tests.

The chart below depicts Quest Diagnostic lab positive rates from 2002 to 2012 compared to self-reported illicit drug use from a study conducted by the National Institute on Drug Abuse (NIDA).

Self-reported illicit drug use is almost three times higher than lab detection.

HireRight Pros and Cons of the Various Drug Testing Specimens

Consider the advantages of multiple specimen drug testing

Employers who have not taken the time to evaluate the various specimens utilized for drug testing, including their strengths and weaknesses, may be positioned with a less effective drug-free workplace program, especially if their positivity rates are artificially low.

For some employers interest has shifted from urine testing alone towards a combination of different specimens to help maximize drug screening program efficiencies and return on investment.


Today, urine remains the most commonly used drug specimen because of its familiarity, its cost to test, and its detection of a wide range of drugs for inclusion on test panels.

A significant problem with urine testing is that it is vulnerable to “cheating“, especially in unmonitored collection situations.


  • Inexpensive
  • Longevity in industry and proven track record
  • Detects recent drug use (previous 4-72 hours)
  • Dependable
  • Approved for federal testing (including DOT)
  • Applicable for a variety of testing reasons including – pre-employment, random, post-accident, reasonable suspicion, follow-up and return-to-duty screening


  • Easily manipulated
    • Adulteration (placing something in urine so drugs will not be detected)
    • Dilution (drinking a lot of water over a short period of time)
    • Substitution (using fluid other than the donor’s own urine)
  • Collection process is not observed
  • Cannot measure frequency of illicit drug use, nor does it indicate severity of impairment

Saliva (Oral Fluid)

Oral fluid drug tests are collected by the donor while under supervised observation which makes tampering with the test sample virtually impossible.

Oral fluid is a good specimen type for remote work locations and organizations who have physical contact with their candidates and employees (i.e. offices, manufacturing plants, distribution centers, etc.).

The narrow but immediate detection window makes it a natural choice for reasonable suspicion testing and for post-accident testing.


  • Inexpensive
  • Detects recent drug use (up to 48 hours)
  • Sample collected under direct observation (difficult to cheat)
  • Lab-based testing has proven to be scientifically accurate (equivalent to urine)
  • Applicable for a variety of testing reasons including – pre-employment, random, post-accident, reasonable suspicion, follow-up and return-to-duty


  • Does not detect illicit drug use beyond 48 hours
  • Cannot measure frequency of use
  • Not currently approved for federal testing (SAMHSA is seeking approval for future federal testing)


Hair testing can be useful in settings where drug testing is scheduled (such as pre-employment and return-to-duty screenings), because of its long detection window.

An individual with substance abuse issues may choose to abstain from drug use for a few days when facing a scheduled oral fluid or urine drug test in order to subvert the detection of drugs in their body.

It can be far more difficult for habitual drug users to refrain from drug use for 90 days in order to pass a hair test.


  • Long detection window (up to 90 days)
  • Higher rate of positive results, and a good test for cocaine detection
  • Can reveal historical patterns of drug use
  • Highest donor “Fear Factor” which may result in some donors electing not to test
  • Not easily subverted
  • Suitable for pre-employment and return-to-duty testing


  • Relatively high cost
  • Takes approximately 5 to 10 days from the time of drug use for detection
    • Poor specimen to detect sporadic drug use, including marijuana
  • Longer turnaround times
  • Challenging when donor has shaved or is void of head/body hair
  • Not approved for DOT federal testing
  • Not appropriate for post-accident or reasonable suspicion because of detection window

Drug Screening Program Considerations

Employers should evaluate the various testing specimens to determine which specimen type best meets the needs of its organization – consider cost, whether testing can be done on-site, and the length of the detection window.

When evaluating a drug screening provider, employers may want to consider these important requirements: Find a drug testing provider with deep expertise and experience in drug testing that is knowledgeable about your industry.

Look for a provider that is able to offer customized solutions, not a one-size-fits-all program. Make sure the provider offers a wide variety of drug screening specimen types and testing panels for different drugs.

Last but not least, an employer should consider looking for a provider with in-house medical review officers (MRO) who can help validate accurate and verifiable drug test results.


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Dr. Todd Simo

Dr. Simo is the Chief Medical Officer and the Managing Director of Transportation at HireRight. He served as HireRight’s medical director starting in 2009 and was promoted to chief medical officer in 2015. Dr. Simo was also appointed to the role of managing director of transportation and drug & health screening in 2018. Dr. Simo came to HireRight with a decade of experience in the medical consulting arena. Before that he was the medical director for an occupational health clinic in Virginia and owned a consulting firm providing medical director services to employers across the United States

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