How Accurate Are Mouth Swab Drug Tests? (2024)

FAQs

How Accurate Are Mouth Swab Drug Tests? ›

A mouth swab drug test is relatively accurate—but only when used correctly.

Mouth swab tests are usually best for detecting recent drug use. Mouth swab drug tests are typically used to detect alcohol, amphetamines, cocaine, marijuana, opioids, and more.

Can substances such as food, beverages, over-the-counter medication, and mouthwash affect the oral fluid drug test results? Yes. For this reason, the donor is to refrain from consumption of food or beverages for 10 minutes prior to specimen collection.

Oral fluid production is stimulated by use of agents such as citric acid candy, chewing gum or other agents. This will inevitably change the pH and concentration of drug in the oral fluid.

Lab-based oral fluid testing offers some notable advantages for employers to consider. Its ability to detect recent use sooner following ingestion than is the case with urine or hair makes it a preferred sampling method for reasonable suspicion and post-accident testing scenarios.

Food, beverages, medication, and mouthwash can all interfere with accurate saliva drug test results. The specimen will either be instantly analyzed on-site or sent to a lab to determine if traces of controlled substances are present in the individual's body.

Amphetamine (more on this below) and methamphetamine are the most commonly reported false positive.

Patient must have diet free of avocados, bananas, tomatoes, plums, eggplant, hickory nuts, walnuts, pineapple and mollusks for 2 days prior to and during the collection. If advised by a physician, the patient should be off all drugs for 3 days. Restrict caffeine, nicotine and alcohol for 24 hours prior to collection.

Current case law indicates that in the context of drug testing, an employer or independent testing firm may be liable for negligence when tests are improperly administered, when test results are inaccurately maintained, and when an employee who has tested positive for drugs injures a third person.

False-negative results occur when a drug or metabolite is present at such low levels that it is not detected. Confirmatory testing is essential to distinguish a true negative from a false negative. Contaminants can also interfere with the immunoassay's ability to detect the presence of drugs.

How to dispute a false positive drug test? ›

If this happened in your case, ask for a retest of your sample. If your employer for some reason doesn't believe your explanation of the positive result, and your retest comes up positive again, it's time to talk to an experienced employment lawyer about the best way to protect your rights.

Mouthwash and Breath Strips: Most mouthwashes (Listermint®, Cepacol®, etc.) and other breath cleansing products contain ethyl alcohol. The use of mouthwashes containing ethyl alcohol can produce a positive test result.

Alcohol detection tests can measure alcohol in the blood for up to 12 hours, on the breath for 12 to 24 hours, urine for 12-24 hours (72 or more hours after heavier use), saliva for up to 12 hours, and hair for up to 90 days.

When compared to urine and hair drug tests, oral fluid is best at detecting recent drug use. Drugs take time to metabolize and pass through the system in a urine test, and the same drugs are incorporated as hair grows and it takes time for the drug to be present in the hair above the scalp.

HHS Approval and Implementation Timeline: The HHS approved oral fluid testing, with DOT's final rule effective from June 1, 2023, however employers cannot use oral fluid testing for DOT regulated tests until laboratories and collection devices are certified.

What testing methodology does Labcorp use to perform initial drug screening? Labcorp performs initial drug screening using immunoassay. An immunoassay is a test that uses antibodies to detect the presence of drugs and other substances in urine.

Saliva has been reliably used to detect HIV-1 and -2, and viral hepatitis A, B and C. It can also be used to monitor a variety of drugs including marijuana, cocaine and alcohol (1). There are compelling reasons to use saliva as a diagnostic fluid to monitor health and diseases.

Results for specimens that screen negative for all drugs are generally available within 24-36 hours after specimens are received at the laboratory. Results for confirmation testing of presumptive positive screens are usually available within an additional 72 hours.

Alcohol detection tests can measure alcohol in the blood for up to 12 hours, on the breath for 12 to 24 hours, urine for 12-24 hours (72 or more hours after heavier use), saliva for up to 12 hours, and hair for up to 90 days. The half-life of alcohol is between 4-5 hours.