DOT Breath Alcohol Technician (BAT) Course Practice Test

The requirement is that the EBT can distinguish between ethanol and acetone at 0.020 g/210 L. This threshold is set because acetone, a common breath component for some individuals (like diabetics or those on ketogenic diets), can cause interference and lead to false positives on some sensors. By ensuring the device reliably separates ethanol from acetone at 0.020 g/210 L, NHTSA protects the accuracy of the reading and prevents acetone from being mistaken for alcohol at that level. In practice, this means the instrument’s discrimination capability must be validated at this concentration so that a true ethanol reading is not confounded by acetone.