A molecule which mimics ethyl alcohol when blown into the Intoxilyzer sample chamber. With the 8000C ethyl ether or diethyl ether. With the 5000C limonene or d-limonene. Acetone and Acetaldehyde are possible interferents but may be flagged by the Intoxylizer as Interferent Detect (or subtract on the 5000C). An interferent can create a false positive or aggravate the readings. An interferent can also compromise the reliability of control tests.