What is the difference between a breathalyser and an alcohol interlock?

A breathalyser and an alcohol interlock both measure alcohol in exhaled breath, but they have different functions.

Breathalyser

A breathalyser is a standalone device used to estimate the alcohol concentration in exhaled breath.

For example, it can be used to check whether alcohol is still present in the body after drinking.

Breathalysers are available with different sensor technologies and varying levels of accuracy.

Alcohol interlock

An alcohol interlock is a system installed in a vehicle and connected to its starting function.

The driver normally needs to provide a passing breath sample before the vehicle can be started.

Alcohol interlocks are used in commercial transport and other settings where sobriety checks are required.

Which should I choose?

If you want to carry out a personal check of the alcohol concentration in your breath, a breathalyser is the relevant option.

If the aim is to prevent a vehicle from starting without a passing alcohol test, an alcohol interlock is needed.

Important: A breathalyser is an aid, not a guarantee that you are fit to drive. Alcohol can affect driving ability even at low levels, and a test result must never be the sole basis for deciding to drive.