Police use several methods to measure blood alcohol concentration (BAC), depending on the circumstances:
1. Roadside Breath Test (Screening Test)
A portable breathalyser measures the presence of alcohol in your breath.
This test provides a quick estimate of whether alcohol is present but is not precise enough for legal proceedings.
It doesn’t test whether you are over the limit, just whether you have alcohol on your breath.
If you fail this test, you will be taken to a police station for further testing.
2. Evidential Breath Test
At the station, a more sophisticated evidential breathalyser is used.
This device provides accurate and legally admissible BAC readings by measuring the amount of alcohol in your breath.
The device is operated by the police officer once the air surrounding the machine (ambient air) has been checked by the machine for the presence of alcohol.
If the machine detects alcohol in the air (e.g. from a previous arrested motorist) it will shut down and not function.
Even if the machine is working, the motorist may not be able to provide the required 2 breath specimens due to a medical complaint e.g. asthma.
3. Blood or Urine Tests
If a breath test cannot be conducted (e.g., due to medical or technical reasons), Gardaí may request a blood or urine sample.
A qualified doctor or nurse will now be called to oversee the taking of blood or provision of urine.
Once the sample is taken/provided it is sent to the state laboratory (Medical Bureau of Road Safety) for analysis.
The results determine the exact BAC level and are legally admissible in court.
Comments