How to Dispute a False Positive Drug Test

Drug testing programs are used to detect illicit substances in your system. These tests most often occur when applying for a job but can also occur as part of random or routine screenings for employees. Drug screenings are implemented to ensure safety and efficiency standards are met, but test results can sometimes be inaccurate.

A false positive test result can greatly affect someone’s position with their current employer and even jeopardize future employment. If someone receives a positive test result, they will likely want to challenge it. Learn what could have caused a false positive test result and how to dispute it.

Types of Workplace Drug Tests

There are several ways to test for drug use, but specific tests are useful in different situations. Employers will consider cost-effectiveness and convenience when deciding which type of drug test to implement. The accuracy of test results may vary depending on when drugs were taken and when testing occurred.

1. Urine Testing

Urine testing remains the most common method of drug testing because it’s cost-effective and non-invasive. Urine tests detect drug metabolites, substances your body creates when breaking down a drug. These substances can stay in your system for weeks, depending on the drug. However, urine tests can struggle to detect recent substance use and are more likely to produce false positives than other testing methods.

2. Hair Testing

Hair testing provides a better view of long-term drug use. Substances move through your bloodstream, end up in your hair follicles, and stay there while your hair grows. Like urine tests, these screenings struggle to detect recent drug use but can detect substances for up to 90 days. Hair tests are difficult to fake but are more expensive than urine tests and are therefore used less often.

3. Saliva Testing

Oral fluid testing excels in areas where urine and hair testing struggle. Saliva testing is helpful for on-the-spot testing because it can detect substances almost immediately after drug use. These tests are practical if an employer has reasonable suspicion of an employee currently on drugs but don’t serve much of a purpose outside a 24-hour window.

4. Other Types

Urine, hair, and saliva testing are the most common screening methods, but other types of drug tests can be useful. Blood tests are the most accurate way to determine if someone has used drugs recently. 

However, like saliva testing, these tests are less effective in determining long-term drug use because substances tend to leave the bloodstream quickly. Because these tests are expensive and invasive, they’re only used when definitive results are needed as soon as possible.

Breath alcohol tests provide instant measurements of the amount of alcohol in your system. These tests, usually conducted with a breathalyzer, are fast and efficient at detecting alcohol but don’t provide any information on drug use or past alcohol consumption.

What Can Drug Tests Detect?

Employers commonly use two types of drug tests: 5-panel drug tests and 10-panel drug tests. These panel tests change color if they detect metabolites attributed to certain substances.

5-panel drug tests detect marijuana, cocaine amphetamines, phencyclidine, and opiates. 10-panel tests detect the same five plus barbiturates, benzodiazepines, methadone, methaqualone, and propoxyphene. Employers can also request customized panel tests to detect other specific substances.

These drug tests will usually be monitored, and collected samples are sent to a laboratory for analysis. An initial screening determines if any drugs are present. If the initial screening returns positive, a more precise test determines what substances are present.

What Causes False Positive Drug Test Results?

Panel tests are meant to be cost-effective and convenient but can sometimes produce false positives. The following are some of the more common causes of false positive results.

Medications

False positive drug test results can be triggered by several over-the-counter (OTC) and prescription drugs, like painkillers, cough medicines, antidepressants, and sleeping pills. Document any medications you have taken if you receive a false positive drug test result.

If you know you have a drug screening coming up, you may consider using alternative OTC medications that won’t affect your results. Continue to take your prescribed medication unless advised otherwise by your doctor.

Substances

Common substances in your household can affect drug test results. Cannabidiol (CBD) oil is closely related to marijuana but does not produce a high. Commonly used to ease pain, CBD oil might cause marijuana to show up on a drug test.

Mouthwash and other breath-cleaning products often contain ethanol, a form of alcohol. Because drug tests can detect trace amounts of ethanol, you may receive a false positive if you’ve used these products. Alcohol-based hand sanitizers can produce similar results.

Food

Employees are often advised not to eat or drink anything 30-60 minutes before a drug test because even food can trigger false positives. Like mouthwash, vanilla extract contains ethanol and can appear on your test results.

Poppy seeds naturally contain morphine and codeine, while coca tea is made with leaves from the same plant cocaine comes from. Consuming any of these before a drug test can produce misleading results.

Laboratory Errors

Sometimes, test results have nothing to do with the individual. Mislabeling or mishandling samples can result in false positives, and urine samples can become contaminated during collection, handling, or testing.

An individual may be able to challenge the validity of the test results if mistakes were made in the testing process or if proper protocol was not followed.

Can You Challenge a False Positive Drug Test?

While rare, it is possible to test positive for drug use even when a person hasn’t used any. This test result can lead to disciplinary action, termination, and legal consequences. Furthermore, the test result can become embedded in your record and threaten future employment opportunities.

If someone receives a positive test result that they believe to be false, it’s reasonable to want to do everything in their power to challenge it.

How to Dispute a False Positive Drug Test

1. Speak to Your Employer

Raising your concerns about your test results is the first step in disputing a false positive. It’s vital to be completely transparent about any medications you are taking or any substances you may have ingested.

Provide any documentation from your doctor regarding your prescription medication. Provide the test administrator with as much information as possible to allow for a retest.

2. Speak to a Professional

If you’re taking medication, speak to your doctor or pharmacist for their professional advice. Ask if any ingredients in your medication may have triggered a false positive test result. If so, ask for documentation highlighting the medication you are taking that could have produced a positive and present it to your employer.

3. Ask For a Retest

Panel tests are not foolproof and can result in false positives. Most employers will agree to a retest if asked. Provide any documentation that suggests the reason for the false positive to justify the need for a retest.

Consider requesting a more accurate test. While most employers understand that panel tests can be unreliable, some may not agree to a retest or will move on to a new candidate if you were a potential hire.

4. Consider Legal Action

Become familiar with employment laws and regulations in your state and consult your employer’s handbook on company drug policy.

You may need to speak to a lawyer if your employer doesn’t believe your explanation for the results and refuses a retest or if you have been suspended or fired. Consult an experienced employment lawyer on your rights and available legal options.

Frequently Asked Questions

Can a False Positive Drug Test Be Proven?

Yes, it’s possible to prove a positive drug test is false. If your initial screening is positive, a confirmation test usually follows to rule out false positives. However, if it yields another positive, you can request a retest and disclose any medications or substances that may have affected the test results.

Final Thoughts

Drug screenings can cause anxiety even when an individual knows they’re clean. A positive test result can drastically affect employment chances, but it’s possible to dispute it if it’s likely false. Taking the necessary precautions before a drug test helps produce accurate results, and knowing the steps to dispute a test result is crucial when receiving a false positive.

ScoutLogic provides solutions to employment drug testing programs, and the lab results are verified by medical review officers (MRO) to ensure accuracy. Contact us today to learn more about our drug screening services.

David Garcia

David Garcia, co-founder and CEO of Scout Logic, is an industry leader in the bulk background check world. With his strategic acumen and expertise in the HR sphere, specifically in hiring, recruiting, legal compliance, background checks, and resume screening, he’s an invaluable asset and consultant.

David's counsel extends across the boards of ScoutLogic, YipitData, and Supplier.io, drawing from his impactful stints on the boards of Infutor and Avetta. With an extensive 25-year journey, he champions unparalleled B2B commercial leadership within data & analytics, significantly shaping the HR landscape.