What’s your call?
It is not unusual for an individual who has a positive alcohol test to claim that the positive alcohol test was caused by _________________ (fill in the blank), and to deny they had been drinking alcohol. We frequently get questions asking whether a subject’s explanation is plausible.
Here is a recent example. On July 5 (one day after the July 4 holiday!) an individual comes in for an alcohol test. The screening test is .091. After a 15 minute observation period a confirmation test gives a result of .082. The individual says “paint fumes in his car” caused him to test positive.
Our response: Breathing paint fumes should not create a reading on the evidential fuel-cell based instrument used for this test. Furthermore, the decline in alcohol level from .091 to .082 (a difference of .009) after 15 minutes is typical for an intoxicated person whose alcohol level is declining.
Our opinion is that the individual had been drinking, was clearly intoxicated, and their explanation about the paint fumes creating the positive test is false.