Breath Temperature | Island Law Office

Breath temperature is a critical component to any breath testing program. Breath testing, in most machines, is assumed to be at 34°C. However, you know what they say about assume? This assumption improperly inflates your client’s true BAC result. Even the police acknowledge this problem in breath testing. The IACT Newsletter, Breath Temperature: An Alabama Perspective, determined in their study that the mean breath temperature was 35.1°C, more than a degree higher than the machine assumes.

This wasn’t an abnormality, but the norm. 93% of the tests were higher than 34°C. The article also points out the Schoknecht Study, which had 700 subjects, versus the minimal amount in the other cited studies, shows a possible temperature as high as 36.7°C, or almost 3°C higher than assumed by the machine.

For each degree C the temperature is over stated, it increases the test result by 6.7% or more. A test result can overestimated by nearly 20%. Reduce your client’s result by the same 20%, and it may very well bring her below the legal limit. Another tool you can find in the virtual library.