A mouth swab drug test detects substances in a person’s system by checking for the presence of drugs or alcohol in the saliva.

People may also refer to a mouth swab drug test as an oral fluids drug test or a saliva drug test.

In companies with drug testing policies, employers often use mouth swab drug tests. A company will usually make it clear when applicants and employees will undergo testing. However, random testing may sometimes also take place.

In some industries, businesses are required by law to test employees for drug use. Under Executive Order 12564, all federal employees working in the following fields are subject to mandatory drug testing:

  • law enforcement
  • national security
  • the protection of life and property
  • public health or safety
  • other functions requiring a high degree of public trust

Mouth swab drug tests are an alternative to urine drug tests. They are easier to carry out and much more difficult to cheat because the sample collection takes place under supervision and direct observation.

Man having a mouth swab drug test.Share on Pinterest
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A mouth swab drug test is a noninvasive method of drug testing that is very easy to carry out. The test also requires very little preparation, with an individual simply having to avoid eating or drinking anything for just 10 minutes prior to the test.

The test involves the use of a sponge or absorbent pad on the end of a stick to swab the inside of a person’s cheek.

An analysis of the sample, either on-site or in a lab, will reveal whether there are traces of specific substances present.

The sample collection time is relatively quick, taking about 1–3 minutes. If the analysis takes place on-site, the results are ready within minutes. If the sample goes to a lab for analysis, it takes about 24 hours to get the results.

When people carry it out correctly, a mouth swab drug test is more than 97% accurate.

According to the Drug & Alcohol Testing Industry Association, drugs do not remain in oral fluids for as long as they do in urine, meaning that this method of testing is more effective in determining current use.

The length of time that certain drugs are detectable in a person’s saliva may vary. Some research suggests that if a person has used a substance more frequently, the presence of that substance will be detectable for longer.

Various factors can affect the accuracy of a mouth swab drug test. These include:

  • the specific type of test
  • the drug under investigation and the quantity of the drug
  • the skill of the person carrying out the test
  • the testing facility
  • the specific detection window of the drug in question
  • whether the sample analysis occurs on-site or in a lab

Mouth swab drug tests can check for the presence of the following substances in a person’s system:

  • alcohol
  • amphetamines
  • barbiturates
  • benzodiazepines
  • tetrahydrocannabinol (THC) — a compound in cannabis
  • cocaine
  • methamphetamine
  • opioids
  • phencyclidine (PCP)

Mouth swab drug tests offer several benefits over other types of tests. These include:

  • fast speed of testing
  • painless for the individual
  • cost effective
  • harder to tamper with the samples

There are only a few cons to mouth swab drug testing. These include:

  • In oral fluid, drugs are detectable for 5–48 hours, which is less than in blood or urine samples.
  • The person carrying out the test requires specific training to ensure that the sample is not contaminated.
  • In some instances, a dry mouth makes taking a sample difficult.

While mouth swab drug tests are accurate, experts consider blood and urine drug tests to be more accurate and effective.

One study, which involved 1,500 paired urine and oral fluid tests, compared the two methods of testing. It revealed that urine drug testing was more likely to detect overall substance use than oral testing.

Drug testing detected substances in 3.7% of the urine samples but only 0.5% of the oral samples.

Mouth swab drug testing is an easy and effective method of drug testing. It is cost effective, painless, and more difficult to cheat than urine drug testing.

However, due to the fact that most substances do not remain in oral fluids for as long as they do in urine or blood, this method of testing is only useful when trying to detect recent drug abuse.

Mouth swab drug testing is common in the workplace. There are no federal laws in place to prevent workplace drug testing.

However, if an employee is not in a safety-sensitive position, some states restrict or question an employer’s ability to carry out random tests for substances. Therefore, businesses should be aware of their state’s specific laws before implementing a drug testing program.