False-positive results from drug tests occur in 5%-10% of cases. When a substance-free sample falsely indicates that a person has used drugs, the report can affect employment, insurance, and other aspects of life. If you have to submit to a drug test, below are a few surprising contributors to false-positive results.

How Can a False-Positive Drug Test Occur?

1. Inhaling Secondhand Marijuana Smoke

Even if you don’t partake, being close to where marijuana is being smoked could compromise your drug test. If you sit next to a marijuana smoker in a confined space for long periods, THC could show up in a urinalysis test. If the room is well ventilated, there’s less risk of this happening. Be sure to avoid second-hand smoke if you are aware that you will be taking a drug test soon.

2. Taking Cold Medications & Diet Pills

If you are taking over-the-counter medications to combat a cold or allergies, let the technician know before the drug test. Some medicines can taint the sample, resulting in the false-positive detection of amphetamines and methamphetamines. This can be the case when a drug contains the antihistamine brompheniramine. If you are taking diet pills, the stimulant benzphetamine can also create a false-positive for amphetamines.

3. Drinking Tonic Water

A standard mixer for many popular cocktails, tonic water contains trace amounts of quinine. Although the medication, used to treat malaria, isn’t illegal, it is often mixed with the illicit drug heroin to decrease its potency. Having quinine in your system might lead the test to conclude illegal drug use has occurred. However, this can often be disputed, and most technicians will understand this false-positive result.

For reliable, accurate drug screening in the St. Louis County, MO, area, contact EMSI-BiState Professional Services. Located in Chesterfield, this center provides substance abuse and pre-employment drug testing and insurance examinations. With over 30 years of experience, you can trust their technicians to conduct the test using ethical and industry standards. To schedule a drug test, call (636) 537-3200. Visit them online for more information about what to expect, and find answers to common questions on Facebook.