Why do I have to hold my breath before exhaling into the iCOquit?

Why should I hold breath before taking a test with the iCOquit?

When testing breath CO, a breath hold needs to be performed in order for the CO level in your blood to equilibrate to the level of CO on your breath. This was clinically evaluated in 1984 by Robert West where he found that ‘CO increased systematically up to 25 seconds of breath holding, with the curve beginning to flatten off at 15 seconds’(1). This was supported in 1986 when Anthony Biglan et al writes that the use of 15 second breath hold is acceptable for discriminating between smoker and non-smokers(2).

Therefore the manufacturers, Bedfont, have adopted 15 seconds as our recommended breath hold time period as this appears to be both clinically correct as well as most acceptable for patients using the device.


1. R West 1984. The Effect of Breath-Holding on Expired Air Carbon Monoxide Concentration in Cigarette Smokers. Addictive Behaviors, Vol. 9, pp. 307-309.

2. A Biglan et al 1986. First Versus Second Portion of Expired Air and Duration of Breath Holding in the Sample of Expired Air Carbon Monoxide.


If the problem persists or has not been resolved by the information provided above, please contact Bedfont or your local distributor for more advice.