The Difference Between Instant Vs. Lab-Based Drug Testing

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Employers who implement a drug and alcohol testing policy are further protecting their company and building a more productive workforce. However, maintaining compliance with state and federal laws while also navigating the complexities of custom drug testing services can be difficult. It’s important to understand exactly how drug testing works to efficiently build a drug testing program that meets the standards necessary to ensure a safe workplace.

What is Instant Drug Testing?

Instant drug testing or Point of Collection Testing (POCT) is drug testing that isn’t performed with a certified laboratory. There’s a variety of devices offered for this method, like oral fluid or urine, that test for a single drug, while others can be used to test for combinations of drugs. Unlike lab-based drug testing, POCT or instant drug testing requires a subjective assessment of the result (e.g., the tester must decide if the test is negative or positive based on visual clues), while laboratory-based drug testing is objective. The primary benefit of a POCT is speed to results, but that speed comes with additional risk of a false positive. Some employers choose to send all POCT samples to a certified laboratory for confirmatory testing.

What is Lab-Based Drug Testing?

Lab-based drug testing is when samples are sent to a certified laboratory to undergo an initial screening test and more stringent confirmatory testing for drugs (e.g., cocaine, marijuana, and amphetamines) and specimen validity (e.g., to determine if the sample has been tampered with). These screening tests tend to be fairly specific and highly sensitive for the drugs being analyzed. If a non-negative sample is detected, labs utilize technologies like gas chromatography/mass spectrometry (GC/MS) to confirm the presence or absence of specific drugs, thereby preventing false positives. Turnaround times for a negative drug test typically range from hours to 1-2 days with a larger TPA like DISA.

Additionally, lab-based drug testing goes through a chain of custody, which is the recordkeeping process of who handles a drug testing sample and why from the time the sample is collected to the time the sample is discarded. Chain of Custody documentation includes both the original sample and any portion of the sample that might be removed from the original container. The documentation provides a paper trail showing the collection, transfer, testing, and disposal of the sample, further verifying its integrity and holds up to any legal scrutiny.


Although instant testing results in a quicker turnaround time for tests, it comes with several considerations, such as:

    POCT does not currently meet standards set by the U.S. Department of Transportation (DOT) and cannot be used for covered employees.

    Lack of standard operating procedures.

    Lack of chain of custody.

    Reduced Accuracy:

     •    POCT devices may not achieve acceptable performance (significantly higher % of false positives vs. lab-based testing).

    •    POCT do not test for the same drugs at the same concentrations as the laboratory-based tests.

    •    Storage conditions of the devices can influence the performance of the device.

    •    Staff must be thoroughly trained on how to use the device and the interpret results. Risk increases as frequency decreases.

    •    Susceptible to donor adulteration.

    •    Unintentional biases towards employees the testing staff has relationships with may cloud results.

    •    No confirmatory testing may be conducted.

    Increased Risk:

      •    May increase liability by acting based on screening confirmation only.

      •    May create HIPAA concerns for donors who are taking valid medications that may appear on a quick test.

      •    Lack of documentation of testing and quality control results may result in legal liability.

    In a certified laboratory, the raw analytical data is available long after the test results are reported. This is not the case in POCT since the majority of POCT results are visual, and the result is handwritten.


What Does the Employer Need to Know?

Employers utilizing drug testing ultimately aim to ensure a safer workplace and need legal defensibility of drug testing outcomes. Because POCT programs don’t always have the same stringent standards as lab-based drug testing, they can give a false sense of security and increase risk. DISA recommends that employers wanting to take advantage of a quicker test result with POCT testing also send those samples to the laboratory for testing. Since lab-based drug testing offers accurate documentation and screening and confirmation processes, employers benefit from a safer workplace and a more legally defensible position if taking any action based on drug test results.

How Can DISA Help?

DISA’s professionals offer expert industry insight to help you build and maintain a drug testing program customized for your company. Our wide array of products and services make it easy to ensure safety for all employees. Whether you’re building a drug testing program from scratch or you’re required under the DOT to implement specific drug testing standards, our professionals can assist you in building a program that meets your needs.

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About DISA Global Solutions

Founded in 1986, DISA is the industry-leading provider of employee screening and compliance services. Headquartered in Houston, with more than 35 offices throughout the U.S. and Canada, DISA’s comprehensive scope of services includes drug and alcohol testing, background screening, occupational health, and transportation compliance. DISA assists employers in making informed staffing decisions while building a culture of safety in their workplace.