Why the Saliva Drug Test Does Not Receive Widespread Use
With the saliva drug test, as with many similar chemical tests, timing is everything. If a test subject can delay a saliva drug test long enough, then the passage of time will erase the ability of the test to pick-up the presence of an illicit drug. Yet that is only one of numerous test features that diminish the chances for a widespread effort to test for drugs in saliva. What are those test features, and why are they important? Details on selected test features are given in the following article.
The saliva drug test has two features that would seem to encourage a wider use of that test. First, it is far easier to obtain a sample for the saliva drug test, than it is to get a sample for a urine drug test. Second the saliva drug test measures the level of the drug and not the level of drug metabolites.
Despite the test’s claim to those two features, the saliva drug test has not received widespread use. Testers are too aware of certain factors that could alter the test results. This article will provide details on those factors, and will highlight why they raise a concern in the eyes of the average test-giver.
The saliva drug test can proceed even if one has only a very small sample. It can detect even relatively minute concentrations of a drug. Yet that very addition to the test’s value also detracts from the usefulness of the test. The saliva drug test requires equipment that costs a good deal of money.
Moreover, the small sample used in the saliva drug test could be easily altered by the appearance of contaminants. That could potentially produce a batch of false positives. Take a look at what might happen if some test subject had previously used a legal, over-the-counter medicine that contained codeine.
Even if that test subject had brushed his or her teeth and had used a strong mouthwash, the ingested codeine would still be present as an oral cavity contamination. Such a contaminant would cause the test to produce a positive reading. Further testing would be needed, in order to demonstrate that the first test result had been a false positive result.
Perhaps improved collection methods could aid acceptance of the saliva drug test. At the present time, the test subject must typically expectorate 3 to 4 times over a 30 second interval. That normally produces a 5 ml sample of saliva. Yet that very collection method has a known flaw. Reliance on such a collection method could lead to a decrease in the concentration of certain drugs. The test-taker generally uses citric acid to stimulate saliva production. The presence in the mouth of that chemical could introduce yet another variable into an otherwise simple test.
The presence in the mouth of citric acid could alter the pH of the saliva sample. In that case the pH would decrease, due to the presence of a weak acid. If the mouth were to somehow allow entrance into the oral cavity of a weak base, then that would increase the pH of the saliva. The decreased pH could lead to a lowering of the concentration of certain drugs, notably cocaine.
One does not need a strong knowledge of chemistry in order to see that the saliva drug test lacks a high degree of reliability. That is why the test has not seen widespread use within the law enforcement community.