To the Editor: Alcohol Breath Testing

As submitted to the New York Times.

Alcohol breath testing devices, when properly calibrated and maintained, are precise scientific instruments to measure the ethanol concentration in breath. Our agency has model specifications for alcohol breath-testing devices in the United States and maintains a Conforming Products List of devices that meet those specifications.

The Volpe Alcohol Countermeasures Laboratory tests every device sent by manufacturers at several blood alcohol concentration levels and at different breath sample volumes and flow intensities before the device is included on the list.

To ensure accuracy, alcohol breath testing programs must perform regular maintenance and calibration checks on their devices, and calibrate their devices when outside of specifications.

In 2018, there were 10,511 alcohol-impaired driving fatalities in the United States. Impaired driving arrests and convictions are based on many factors, and do not rely solely on a breath test. Properly calibrated and maintained alcohol breath testing instruments are an important tool for law enforcement, and our roads are much safer with the help of these devices. 

—James C. Owens
Washington