What drinker would not want a device to help them decide whether it was safe to order another drink or whether it was safe to drive home after a night of partying? Such a magic device would certainly eliminate the drinker’s obligation to monitor their alcohol consumption and to assess their BAC based on knowledge of standard drink units and their gender and body weight. After all, who wants to be troubled with all that thinking when there is drinking to do? When a need exists, a product is sure to follow. A proliferation of inexpensive Personal Portable Breath Test (PPBT) devices that promise to tell drinkers if they are safe to order another drink or if they are safe to drive after drinking are flooding the market. Are these devices the answers drinkers have been looking for, or are these devices a risk to personal safety?
To examine the question whether the use of personal portable breath test devices to make next drink and/or driving after drinking decisions is appropriate, the author collaborated with the National Alcoholic Beverage Control Association (NABCA) and the Institute of Police Technology and Management (IPTM) to test a random sample of PPBT devices for accuracy and usability during Standard Field Sobriety Test (SFST) training wet labs.
Thirty-two commonly available PPBT devices were purchased from mail order catalogs, from local auto parts and big box stores, and through the internet. The study devices ranged in price from $9 to $260. While almost all of the packaging noted that the products received FDA 510(k) clearance or US Department of Transportation – National Highway Traffic Safety Administration (NHTSA) approval as an alcohol-screening device (ASD), none of the devices tested was listed on the DOT Web Site as an approved device and no listing for FDA 510(k) clearance devices was found.
In the study protocol, volunteer drinkers consumed alcoholic beverages until their BAC level was in the 0.08% to 0.10% range as established by an evidentiary breath test devices certified for use in criminal DUI investigations. The SFST volunteers utilized each of their assigned PPBT devices within 10 minutes of obtaining their baseline BAC results establishing an accurate comparison between the PPBT and the evidentiary results.
Each of the 32 PPBT devices deviated from the legal standard. Some exhibited significant deviation. The average BAC for all the drinkers based on the evidentiary device was 0.09 %g, or slightly higher that the presumptive level for DUI in all 50 states. The average BAC for all the PPBTs was 0.125 %g, or 39 percent higher than the evidentiary device. At first glance, this deviation, while representing a significant error, was an error that informed the drinker that their BAC was considerably higher than it actually was. From a personal safety perspective, this error may be positive perhaps resulting in a decision to discontinue alcohol consumption before the drinker was a risk to him and others. However, these results were skewed by three devices that reflected BAC results over 0.30 %g, values that represented 4 times the presumptive level of intoxication.
The overall results did not accurately represent the results from each device. Individual PPBT results ranged from 0.03 %g BAC to 0.47 %g BAC. Fifty six percent of the devices overstated intoxication while 44% underrepresented intoxication. As previously stated, devices that over-represent intoxication may have the personal safety benefit of causing drinkers to discontinue consumption. However, devices that under-represent intoxication levels could have the opposite effect. Considering that several devices reported a 0.03%g BAC when the drinker’s actual BAC was 0.09 %g suggests that many of these type devices could actually encourage drinkers to continue to consume alcohol even when their actual BAC is above the presumptive level of intoxication. Eleven of the 32 devices, or over 1/3 of the PPBT devices, reflected a test result lower than the baseline device. The implications of these results is that with 11 of these devices, drinkers would incorrectly believe that their BAC is lower than it actually is which may lead to additional alcohol consumption or poor decisions concerning the operation of a motor vehicle.
The PPBTs obtained for the study ranged in cost from $9 to $260. Preliminary results suggest that the purchase price of the PPBTs does represent PPBT accuracy to a limited degree. For example, two devices varied only 0.002 g% BAC from the evidentiary device results. These devices cost $150 and $200 respectively. However, some lower-priced PPBTs performed almost as well and several higher-priced PPBTs did not perform as well.
While cost alone was not a determinate of expected result accuracy, the more expensive devices, those costing over $180, did not substantially underestimate BAC level. Underestimation presents the most significant risk to personal safety in that it might encourage the drinker to consume more alcohol believing their BAC is actually lower.
Several of the devices displayed results with a combination of green, yellow, and red LEDS rather than through a digital display. These devices, in general, were the most inexpensive and had the highest rate of failure to operate. The devices indicated a threshold level of 0.05 g% BAC and not the threshold limit for intoxication presumption utilized in the United States (0.08 %g). That notwithstanding, the devices that displayed results with color LEDs rather than a digital display were not accurate in depicting BAC levels. Their use probably should be limited to simply determining the presence of beverage alcohol rather than determining a value.
While most of the instructions included with the PPBTs told the drinker to wait a specified period after drinking to utilize the device, it seems unlikely that a drinker would wait the generally prescribed 20 to 30 minutes before utilizing the device in a drinking environment and before making a next purchase or drink after drinking decision. In addition, only a few instructions explained to the user that his or her BAC level would continue to rise for 30 to 45 minutes after last drink consumption and that the BAC reading, even if taken 20 minutes after last alcohol consumption, would be inaccurate as the BAC level rose.
Personal portable breath test devices are commonly used by drinkers to make next drink decisions and to make driving after drinking decisions. These decisions appear to be based on an expectation that the PPBT devices are accurate. Drinker expectations of PPBT accuracy seem largely based on the information contained on the product packaging. Presumptions of accuracy may also be subjectively based on purchase price with the user assuming more expensive devices are more accurate.
The PPBT devices tested were largely found to be inaccurate and inappropriate for drinker intoxication self-assessment. While several devices were quite accurate and reported drinker BAC levels within 0.002 g% of the benchmark breath test device results, most of the devices presented significant variances from the benchmark. The high variance could reasonable lead drinkers to believe that they were not intoxicated to the extent that their faculties were impaired when in fact they were a risk to themselves and others.
The devices that utilized colored LED lights to indicate BAC levels, when they actually worked, were highly inaccurate. Because of this, the devices that relied solely on colored LED lights would only be useful to detect the presence of beverage alcohol and should not be used for quantification. Each of these devices utilized a 0.05 g% level to indicate intoxication. This intoxication presumptive level is the standard in much of Europe and Canada. Using a threshold level of 0.05 g% instead of 0.08 g% could be confusing to drinkers in the United States.
Many of the study participants complained that the PPBT operating instructions were not easily understood (it appeared that the instructions for several devices were poorly translated from Chinese into English). The operating procedures for other devices were found to be overly complicated requiring operators to depress several buttons in a prescribed order and for a specific duration before the device would operate. Instruction confusion and difficulty in operation may discourage drinkers from using the products even when the devices may provide some benefit. This is especially true when the user’s BAC is approaching 0.08 g%. Most of the devices suggest the owner return the PPBT for calibration every 6 months or 1 year. It is unlikely that many PPBT owners would return the devices for calibration as suggested possibly resulting in greater inaccuracies.
With only a few exceptions, the written instructions did not advise the drinker that their BAC level would continue to rise for 30 – 45 minutes after consuming their last alcoholic beverage. This information is critical and the absence could lead a drinker to believe that the BAC level displayed by the unit was in fact the level upon which they should make their decision to drive or to have another alcoholic beverage.
About the Author: Maj. Mark Willingham served with the Florida Division of Alcoholic Beverages for 30 years where he policed and regulated the alcoholic beverage industry. He currently provides consultation and expert witness testimony concerning the responsible service of alcoholic beverages through Alcohol Solutions, Inc.