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Understanding Drug Abuse and Impairment in the Workplace

Posted on Monday, May 22nd, 2023

By Yvette Farnsworth Baker, Esq., Senior Legal Consultant at Current Consulting Group (CCG)

Click Here to View the Original Article on the CCG Website

Note: This article is provided for educational purposes only and should not be relied upon as legal advice. The reader retains full responsibility to ensure compliance with all applicable laws relative to drug testing.

While drug testing for illegal drugs is the backbone of an effective workplace drug testing policy, policies that go no further than illegal drugs can still fail in their goal. With the widespread prevalence of the opioid epidemic, prescription drug abuse, and the legalization of marijuana, workplace drug testing policies need to address the abuse of legally obtained substances and impairment on the job to be truly effective.

Use Versus Abuse

Differentiating between drug use and drug abuse is critical with legal substances like prescription medications and alcohol. Many prescription drugs are highly addictive and use that began as beneficial can quickly spiral out of control. Additionally, the use of other substances, such as alcohol, may be acceptable in certain circumstances, but can escalate to abuse that affects workplace safety and the well-being of the employee. Drug abuse leads to an increased risk of problems and an inability to control use.

There are several steps to identifying employee substance abuse. The first is through drug screening and use of a Medical Review Officer (MRO) to verify valid prescriptions. But even employees with a valid prescription can be abusing the drugs they are prescribed. An employee may use their prescription medication at times or in quantities that make them unfit to perform their job effectively and safely. This is especially dangerous for safety sensitive positions. These can include not only DOT safety sensitive workers, but also employees who handle sensitive data, work with hazardous chemicals, drive a work vehicle, etc.

On the other hand, disability law requires employers to allow prescription drug use by employees that is in appropriate prescribed quantities and does not affect safety or their ability to perform the functions of their position. Employers cannot lawfully ban prescription medications or require that all medications be reported to management. There is a balance required by law between maintaining the safety and effectiveness of the workplace and upholding the rights of employees with medical needs.

Employers should craft workplace policies and implement processes to identify drug abuse and to differentiate between appropriate use and abuse. Employers can work closely with professionals in workplace drug testing, law, and human resources to follow disability law while also establishing policies and practices that address drug-abusing employees in the workplace.


Like drug abuse, drug impairment is another tricky line to identify. In what circumstances can a person have used an intoxicating substance but not be impaired by it? The easiest way to understand this difference is by looking at the history of alcohol testing.

Science has told us for over a century that alcohol use affects the brain and body’s function and can cause people to engage in risky behaviors. In the early 1900s a test was created to identify alcohol metabolites in a person’s system that showed they had ingested alcohol within a certain period. However, these metabolites could be identified in a person’s system even after the intoxicating effects of alcohol had worn off.

As time went on, the scientific community was able to identify what level of blood or breath alcohol concentration (BAC) has an impairing effect. By 2004, all 50 states had established BAC limits of 0.08% for driving. If a person tests at or above 0.08%, they are impaired by alcohol. If they test above zero but less than 0.08%, they have ingested alcohol but were not definitively impaired by alcohol at the time of the testing.

To prove impairment for purposes of Driving Under the Influence (DUI) crimes, law enforcement has two methods. The first is to prove that a person tested over the “per se” impairment level of .08% BAC by using a bodily fluids test. The second is to prove that the person was impaired. This is generally done by observing the person’s behavior or appearance, be it driving pattern, performance of roadside tasks, bloodshot eyes, etc. When law enforcement cannot use a bodily fluids test, perhaps because the person refused to take the test or equipment was not available in a timely manner, they use evidence of impairment.

In the workplace, knowing the signs of impairment can be extremely useful. Signs of impairment can be used to show that an employee is using a lawful substance, such as prescription medication, in a manner that makes them unfit for the job. Signs of impairment can give an employer probable cause to drug test a certain employee. Signs of impairment can be used for drugs such as marijuana, which can stay in the system for a long time or for which impairment cut-off levels are not well established.


Testing for marijuana is becoming problematic with widespread marijuana legalization. Marijuana is a drug whose metabolites can remain in a person’s system for a long time after impairment has worn off. Additionally, the scientific community has not reached a consensus about a marijuana cut-off level that conclusively indicates impairment. So, when solely utilizing drug testing, it is extremely difficult to know if marijuana use is abuse and/or demonstrates impairment.

Oral fluid testing is currently the most suitable drug test for capturing marijuana impairment. This is because oral fluid testing captures only recent use. Oral fluid does not retain marijuana metabolites like other bodily samples do, so an oral fluid drug test detects the parent drug rather than the metabolites. The parent drug exits a person’s body much more quickly than metabolites do, so a positive marijuana test in oral fluid evidences only recent marijuana use and is much stronger evidence of impairment.

As many as ten states and the District of Columbia restrict workplace discipline for off-duty recreational marijuana use. Many states also restrict discipline for off-duty medical marijuana use. California is one of the latest states to pass laws prohibiting refusal to hire or termination of employment for marijuana use unless the individual was impaired on the job, used marijuana during work hours, or possessed marijuana in the workplace. Other states with similar laws include Connecticut, Illinois, Maine, Missouri, Montana, New Jersey, and Rhode Island. New York has the most restrictive law prohibiting nearly all workplace testing for marijuana. Some states do provide exceptions for safety-sensitive positions or employees who could pose a danger if impaired in the workplace, so it is important to research the details of each individual state law.

In the past, it was not necessary to prove marijuana impairment instead of marijuana use because marijuana was an illegal drug and any use at any time was grounds for workplace discipline. However, now many employers must prove additional factors before disciplining an employee for testing positive, such as impairment on the job, use or possession at work, or a safety-sensitive position. This makes an understanding of use versus abuse and use versus impairment vital, particularly as marijuana use increases nationwide.

Action Items

There are several important steps that employers can take to combat drug abuse among employees. Employers should regularly review their workplace drug testing policies. Workplace policies can address not only illegal drug use but prescription drug abuse as well. An MRO can assist with identifying false prescriptions, outdated prescriptions, or use in quantities higher than prescribed. Policies can also utilize signs of impairment at work. Employers should take care to understand the laws surrounding marijuana in their state and to be sure that their policies conform to the requirements of their state laws.

Additionally, employers should consider what testing methods are most appropriate for their workplace. Identifying recent use is best done through oral fluid testing. Instant results can be obtained through on-site testing as opposed to lab-based testing. But again, employers need to know the state laws surrounding workplace drug testing for the states in which they operate, as not all testing methods are permitted in every state.

Above all, employers need to be sure they are addressing the very real risk of drug abuse and impairment in the workplace. Physical safety of employees and the public, safety of sensitive data, legal liability, and productivity are all placed in jeopardy when drug abuse is not curbed or monitored in the workplace.

© 2010-2023 The Current Consulting Group, LLC – No portion of this article may be reproduced, retransmitted, posted on a website, or used in any manner without the written consent of the Current Consulting Group, LLC. When permission is granted to reproduce this article in any way, full attribution to the author and copyright holder is required.

The post Understanding Drug Abuse and Impairment in the Workplace first appeared on ClearStar.

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