Passive Alcohol Testing

When we think of alcohol testing we usually visualize someone blowing into a mouthpiece mounted on a breath testing device.  This typical method of alcohol testing is referred to as “direct” testing.  However, there are many screening situations that call for using breath test devices capable of conducting a “passive” test.  Passive alcohol testing does not require an individual to blow into a mouthpiece, but towards the device, which allows the operator to quickly screen for the presence of alcohol.

Whether your need is to screen an individual or large groups of people, passive testing can be an effective deterrent to alcohol use.  High school dances, shelters, and substance abuse treatment group meetings are some examples where passive testing can be used. Individuals found to have alcohol on their breath through passive testing, can be given a direct breath test to determine their intoxication level. Other advantages to passive testing include:

• No mouthpiece is required:  The PAS IV and PAS Sentry do not require mouthpieces.  Alco-Sensor FST and Alco-Sensor VXL utilize reusable passive sampling cups. No mouthpiece means there’s less cost-of-use associated with the device.
• Quick testing sequence:  Alco-Sensor FST can perform a passive test every 10 seconds.  Because the subject does not touch their mouth to the sampling cup the operator does not need to change the cup between negative tests, which also speeds the test process.
• The ability to test beverages or an environment for the presence of alcohol:  When a liquid contains alcohol, a small amount of that alcohol is constantly evaporating from the liquid and can be detected by the passive device simply by testing the air just over the surface of the beverage. Being able to conduct passive testing whether in a beverage or environment such as a vehicle, can identify people or situations that present potential harm.

Qualitative Results, Not Quantitative

Passive alcohol tests give qualitative results, or pass / fail results.  Because the devices are not able to precisely control the volume of breath being measured they are not able to accurately measure intoxication level.  They can, however, readily detect whether an individual has alcohol on their breath or not.  Some devices, such as the Alco-Sensor FST and the Alco-Sensor VXL, display results as “positive” or “negative.”  Other devices, such as the PAS IV flashlight, use a colored bar graph to indicate presence of alcohol at relative concentrations. Because passive testing devices cannot report on intoxication levels, it may in some cases become necessary to pair passive testing with direct testing practices.

How Passive Alcohol Testers Work

The passive test devices manufactured by PAS International use a small pump that runs for several seconds, pulling air into the sensor.  When testing an individual, the operator instructs the subject to blow at the device as the operator starts the sampling pump.  The pump then pulls some of the subject’s breath into the device.

The Alco-Sensor FST and Alco-Sensor VXL use a passive sampling cup in place of a mouthpiece.  The cup concentrates a person’s breath into the breath sample port.  As the subject blows at the sample cup the force of the breath automatically triggers the Alco-Sensor to sample the breath.

To learn more about passive testing devices and when best to use passive testing techniques, speak to an AlcoPro representative at 800.227.9890.