EHS OutLoud Blog

False Positive: Employers Should Re-Examine Drug Testing Policies


As safety professionals and HR personnel, we have our employees conduct random, post-accident and new-hire drug tests as a condition for hire. Although the medical reviewing officer (MRO), gives them what they consider adequate time to submit proof of medication, what happens when they can't produce it because they have truly never even tried any drugs? Do we terminate the employee? Do we decide not to hire them? 

Do we get rid of maybe one of our best hardest most loyal employee because a test concluded he was positive for opioids because he likes to treat himself to a cream cheese and poppy seed bagel for breakfast?  Do we ruin the career of a 20-year long employee because her new weight loss supplement says she is positive for THC – all because some vitamins have hempseeds as a natural supplement?

I go through this at every project at which I have to get drug test,  and it is embarrassing.  At one point, it even made me think about quitting as soon as I got the calls from the office telling me I had "popped hot" in a drug test.

Six years and eight months. That is the amount of time I proudly served the United States while on active duty.  After all that time and multiple deployments, I suffer from back, knee and shoulder pain, among other things. I have a medicine cabinet full of VA-prescribed medicine that I take from time to time when I have flare ups. 

Every time I take a urinalysis for a new job, I go through the same thing. I get a call from the MRO, and once again I have to fax in my VA medicine list to show I am not taking any illegal drugs. If you fail to fax the list in right away or within adequate time, it becomes a nightmare at work. Everyone you know believes you are the worst drug addict in the world.

A study published in The Journal of Opioid Management shows that the possibility for false positives and negatives do exist. Not only do they exist depending on the drug being tested and the type of test being conducted, the percentage of false positives can range anywhere between 20 percent to 50 percent in some instances. 

In an article, Charlene Latino talks about the research from a study conducted by Dr. Dwight Smith and colleagues at the Boston Medical Center. Information presented at the American Psychiatric Association's annual meeting stated that their research dating back to the 1980s show that false positives have been triggered by common household ingestions.

Over-the-counter medicine, weight loss supplements, antidepressants even some regular food we eat could trigger false positives.  A teaspoon of poppy seeds (less than that on a bagel) could cause a false positive for opioids, said Smith.

Instead of biting the bullet in the form of drug test cost, let’s allow workers to retest at a different facility or even the same facility, but with a new urine sample. It’s pointless to retest the same sample. If the employee cannot give you evidence of the medication they're taking, it doesn’t automatically mean they're lying and are drug addicts. There is plenty of proof that shows urine drug tests are extremely inaccurate. 

Maybe a second look at your drug and alcohol substance abuse program may not be such a bad thing.  

Josue M. Zamarron, STS-C, ASHM, CSHO, has been in construction safety for more than ten years. He started his career as a safety tech in high school for a small drywall company and joined the military after high school. After serving two combat tours, Zamarron left to become a safety instructor, helping veterans get free training and become employed.  He currently is a project safety manager.

Discuss this Blog Entry 3

on Dec 7, 2016

Do you have a link to the Journal study?? I really would love to follow up on this for my people.

on Dec 12, 2016

This blog is totally inaccurate. Were any of these claims investigated or checked out before publishing??? As a Substance Abuse Program Administrator certified in 1998 and with 21 years experience in the workplace drug testing field I can address each and every one of the claims made in this blog as false.

'False positives' are rare IF workplace testing is done properly using an HHS certified lab for testing and a certified Medical Review Officer. Many employers are fooled into thinking they can short cut the process by using quick test devices eliminating proper and correct collection procedures, lab testing via EMIT and GCMS and finally qualified MRO.

The levels used in HHS certified labs for workplace drug testing is set by the federal government and is called the Threshold Detection Level. The levels were set based on studies specific to judgement and motor skills while under the influence of certain drugs. It has been determined that these drugs, narcotics, marijuana, amphetamines, methamphetamines, cocaine affect abilities in the workplace. A specimen testing positive is tested twice at least by two different methods.

The lab in using GCMS testing for confirmation counts parts per billion of a prohibited (by company policy and or request) substance in a submitted specimen and can identify nutritional substances from drug substances in the system.

No poppy seeds, everyday foods or even hemp seed ingestion will result in a positive drug test. As a matter of fact hemp seed products are often made with the male hemp plant, not the female therefore not containing THC certainly not at levels to be detected by workplace testing.

The MRO requires submission of the name of the prescribing physician and fulfillment pharmacy for any legal prescription that is identified by the lab.The call to the candidate is CONFIDENTIAL and there is a time frame of 72 hours to submit the information. The faster the candidate submits the faster the negative result is forwarded to the employer. What kind of nightmare can that be???

The reference to the Journal of Opioid management is inappropriate when discussing workplace testing. The levels identified in addictive treatment protocols are not comparable and testing is done more frequently to address ongoing abuse issues as part of treatment protocols.

Narcotics, stimulants, tranquilizers and antidepressants are only effective 4-6 hours. Marijuana, if used more than casually, twice per week or more, cam accumulate in the body affecting motor skills for a longer period of time. Hence the longer window for a positive result. Opioids are not typically tested for as they are NOT part of a typical five or ten panel test. Opioids are synthetic and must be tested as a specific requirement with additional processes.

This is the reason another specimen cannot be submitted, the substance is metabolized out of the body in 8-12 hours. Submitting a second specimen two or three days later will always be negative as the candidate has time to prepare, by not using or flushing his/her system. Also Federal, State and DOL employment law prohibits the submission of a second specimen in the case of a lab confirmed positive for this exact reason.

Workplace drug testing is done on applicants who should by rights, be presenting their best possible face to be considered for hire...clean and ready for work. Testing done as part of a random program, after and accident or on reasonable suspicion conditions is during work hours when none of these mind altering drug should be in the system. Prescription drug like narcotics, even if they are legally prescribed, can be a safety concern and should not be used on worksites, rather over the counter, Aleve or Ibuprofin, used to control pain and to assure safe working conditions.

I am not aware of any statistics or proven facts to support the claim false positives are common. I would be very interested in seeing any facts with references to prove these claims.

Again, it's all about safety and limiting liability. Accidents and injuries are expensive and can affect one's ability to provide financially for a lifetime. It's all about safety, folks!!

on May 23, 2017

The article claims 20% or more false positives. I manage a workforce of over 500 people and in the last 6 years I've only had two people CLAIM that they were falsely positive (one of whom later admitted to using). That's it. One in six years. That's more that 4000 drug screens.

Please or Register to post comments.

What's EHS OutLoud Blog?

EHS OutLoud blog provides a candid look at health and safety issues both at work and at home.


Sandy Smith

Sandy Smith is editor-in-chief of EHS Today magazine, a Penton Media Inc. publication. She has been writing about occupational safety and health and environmental issues since 1990. She has been...

Stefanie Valentic

Stefanie Valentic is an associate editor for EHS Today magazine, a Penton Media Inc. publication.  A native of Cleveland, Ohio, she has been in B2B publishing for eight years. Her work has...
Blog Archive

Sponsored Introduction Continue on to (or wait seconds) ×