Worker Drug Testing: Defending False Optimistic Allegations

Drug testing is getting more and more complicated for employers. According to Quest Diagnostics’ drug test index, the workforce’s drug test positivity rate reached its highest level in 16 years in 2019, with marijuana drug test positivity increasing by double digits. The employers control this increase, disability and discrimination problems as well as the state level Occupational health and safety for some medical and recreational marijuana use.

Regardless of the complexity of these changes, one thing remains the same: people will fail drug tests and will complain and claim that they have never used drugs and that the drug test given was flawed and / or discriminatory.

Often times, such a lawsuit is brought after an employee or applicant fails a drug test and then passes a second drug test that they have secured themselves. This article offers some helpful tips to ward off such claims.

First steps

The first thing to do is to determine whether the worker or applicant claims they have been exposed to drugs in the environment. This is usually a claim of exposure to secondhand smoke or living with a drug user, but is sometimes made by a law enforcement officer who interacts with drugs in the course of his or her engagement.

Often times, in false positive drug test cases, the plaintiff will expressly reject any exposure to drugs. This is a helpful fact as the presence of drugs in their system – especially on the second test – is compelling evidence of willful illicit drug use.

Second, a second drug test often provides evidence to support the results of the first drug test, even if the second drug test is rightly interpreted as negative. In particular, the second drug test often shows evidence of drugs below, sometimes just below the laboratory limit and / or more than the spiked control The samples go through the drug testing laboratory process. (Such samples – with known drug concentrations – are tested to ensure that the laboratory process is working properly.)

In the absence of pollution, there is no legitimate explanation for the presence of drugs on the second drug test, meaning that the second negative result supports the first positive result. As drug testing lab directors like to say, “A negative test result doesn’t necessarily mean there was no drug in the sample.”

If the drug test at issue in the litigation was conducted as part of a series of drug tests, a table shows the limit value used, the drug levels obtained by examining various laboratory control samples, and the results of all drug tests performed.The batch in question can be a very useful method to measure to show why the plaintiff’s second negative drug test is actually confirmation of the first positive drug test. Typically, the plaintiff’s sample is close to the limit and / or differs from the bulk of the “no-drug” samples shown in the table.

Third, there are often legitimate reasons why the second sample was negative, even if no drug was found in the second sample – reasons that do not cast doubt on the scientific validity of the first drug test. The time lag between the first and second drug tests is often the explanation why the sample donor failed the first test and passed the second drug test.

With a time lag, the second negative test ordered by the plaintiff is often only the result of drugs that disappear from the dispenser system. This is a particular risk with urine drug testing given the short half-life of drugs found in urine and the ease with which a sample donor can flush their system with water.

In addition, comparing one drug testing modality to another drug testing modality (hair to urine, oral fluid to urine, etc.) is usually an apple versus oranges comparison – especially due to different “look back” periods.

For example, hair drug tests typically identify drugs that were used in the seven to 90 days prior to the test. Urine and oral fluid drug testing usually identifies drugs that have been used more recently, but nowhere near looking back at drug testing for hair.

Even if the same modality is used (urine versus urine, etc.), different laboratories use different technologies and methods in their testing process. The natural and legitimate variation in results caused by different technologies can often explain the “mismatched” results between two drug tests.

Claims another substance caused a positive result

Finally, employers routinely face litigation claims that another substance (prescription drugs and CBD, but also mentholated steam inhalers and even poppy seed bagels) produced a “false positive” drug test result.

Fortunately, employers can rely on their drug testing Medical Review Officer (MRO) to determine the legitimacy / illegitimacy of such claims by interviewing the donor, securing prescription copies, evaluating laboratory results, etc. Do you know MROs have the skills required to do such an analysis; Employers should rely on this and not try to make such decisions themselves.

Employers should also be aware that prescription drugs and the use of CBD often pose problems of disability discrimination, which should be resolved through an informal interactive dialogue between the employee and the human resources department in order to find reasonable accommodation for a person’s disability To discuss the employee.

Similarly, medical marijuana, and sometimes even recreational marijuana, often have professional rights that require dialogue similar to the Disabled Americans Act. Note that the ADA itself does not provide protection for medical marijuana as marijuana is still illegal under federal law. Dialogue is required for state ADA analogues such as the New Jersey Law Against Discrimination, Massachusetts Chapter 151B, etc.

Drug testing is an area where labor law is changing rapidly. All types of drug testing-related lawsuits, including “false positives” claims, are being filed in ever increasing numbers. Even in this brave new world, discerning employers can defend their drug-free workplace policies and reject such claims.

This column does not necessarily reflect the opinion of the Bureau of National Affairs, Inc. or its owners.

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Michael K. Clarkson, a shareholder in Ogletree Deakins’ Boston office and co-chair of the company’s Drug Testing Practice Group, works regularly with employers and is a leading voice on critical drug testing issues. He drafts compliant guidelines for drug testing, advises on drug testing issues and defends employers against “false positive” claims about drug testing.

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