Many asthma inhalers operate primarily by injecting a mist containing a substantial quantity of alcohol into one's lungs. This alcohol does not pass into the blood stream, but remains in the alveolar lining of the lungs; from there the alcohol will be exhaled into the breath machine.
California DUI breath tests are problematic as they are designed to assume that the breath sample contains alcohol which has been swallowed and then metabolized by the body before being diffused into the lungs.
California DUI breath tests also assume that there are 2100 units of alcohol in the blood for every unit measured on the breath. So the breathalyzer’s computer mistakenly multiplies the alcohol measured from the asthma inhaler 2100 times. So a very tiny amount of alcohol in the lungs from the inhaler mist can have a very large effect on the California DUI breath test machine’s reading.
A number of asthma inhalers can cause high scientific readings on breath machines due to the propellent gasses used in the aerosols, in particular, chlorofluorocarbons. See "Using Asthma Inhalers Can Give False Positive Results in Breath Tests", 324 British Medical Journal 756 (March, 2002). 1 of the design defects in California DUI breath machines is that they are non-specific as they falsely report thousands of different chemical compounds as being alcohol.
Some of these contain alot of alcohol. For example, Primatene Mist contains 34 percent alcohol.
Note there are experts who maintain that asthma inhaler's mist would dissipate over the required minimum 15 minute continuous observation period just prior to the California DUI breath test.