A breathalyser is a device that can change a driver’s professional and personal life in a matter of seconds. It is worth knowing how a proper test is conducted, what rights you have during a check and when a breathalyser result can be effectively challenged.
How a Breathalyser Works
A breathalyser measures the concentration of alcohol in exhaled breath and converts it into a result expressed in milligrams of alcohol per cubic decimetre of exhaled air (mg/dm³ or mg/l). The result is converted into an approximate blood alcohol concentration using an established coefficient.
Devices used by the police operate on the principle of electrochemical oxidation of ethyl alcohol or infrared spectrometry. Both types have a defined measurement accuracy and permitted error margins.
How a Proper Test Should Be Conducted
A proper breathalyser test requires a specific procedure to be followed.
The observation period. Before the test begins, the officer should observe the driver for at least fifteen minutes, during which time the driver should not eat, drink, smoke, chew gum or use an inhaler. Substances in the mouth can distort the result.
Two measurements. The test should consist of two measurements taken at least fifteen minutes apart. Where a result above 0.00 mg/l is recorded, a second measurement must be taken using the same or a different device.
The result on the display. The driver has the right to see the measurement result on the device’s display.
The test record. A record of the test is prepared containing: the date and time of the test, the model and serial number of the device, the results of both measurements and the driver’s details. The driver should receive a copy of the record or have the opportunity to read its contents.
What Your Rights Are During a Test
The right to information about the device. You may ask for the breathalyser model and serial number – this information will be needed if you subsequently challenge the result.
The right to see the result. You have the right to see the result on the device’s display immediately after the measurement.
The right to a second measurement. You have the right to request a second measurement after fifteen minutes have elapsed.
The right to a blood test. You have the right to request verification of the breathalyser result by a blood test. A blood test is a more precise method – the laboratory result takes precedence over the breathalyser reading. This is particularly important at readings close to the legal thresholds (0.10 mg/l and 0.25 mg/l).
The right to remain silent. You are not required to answer questions about when and how much you drank – you have the right to decline to give an explanation until you have consulted a lawyer.
Can You Refuse the Test?
Refusing a breathalyser test is not legally permitted without consequences. Legal provisions provides that refusal is treated as a positive result – meaning the authorities will proceed on the basis that the driver was under the influence of alcohol. Refusal does not protect against liability – it worsens the procedural position.
The only exception is a medical condition that prevents the driver from undergoing a breath test – in which case a blood test is possible instead.
When You Can Challenge a Breathalyser Result
A breathalyser result is not absolute evidence. In court proceedings it can be effectively challenged in several situations.
No valid calibration certificate. Every breathalyser used by the police must hold a valid calibration certificate issued by an accredited laboratory. The certificate has a defined period of validity. Where the device had not been calibrated within the required period, the result may be challenged as having been obtained using a device not approved for use.
An improper test procedure. The absence of a fifteen-minute observation period, failure to take two measurements, failure to observe the required interval between measurements – any of these shortcomings can form the basis for challenging the validity of the test.
Measurement uncertainty. Under metrological regulations, the permitted measurement error for results up to 0.4 mg/l is ±0.02 mg/l. At a reading of 0.10 mg/l or 0.25 mg/l (the legal thresholds), measurement uncertainty may mean the actual concentration was below the threshold. The principle of resolving doubts in the defendant’s favour requires the most favourable result to be adopted.
Substances that interfere with the measurement. Certain medications, mouthwashes, chemical substances in the working environment and even some diets can affect the test result. Where the driver was using preparations that could have distorted the reading, it is worth informing the lawyer.
Improper storage or transport of the device. Breathalysers are sensitive measuring instruments – improper storage conditions can affect their accuracy.
Breathalyser result versus blood test result. Where the breathalyser indicated a legal breach but the blood test showed a result below the threshold, the blood test result is determinative.
The Importance of the Test Documentation
The breathalyser test record should contain all key data: the time of the test, the model and serial number of the device, the results of both measurements. Keeping a copy of the record is the first step towards any subsequent defence.
An application for access to the case file after it has been sent to the prosecutor’s office or court will allow the device’s calibration certificate to be obtained and the procedure to be verified.
Contact Us
If you have doubts about whether a breathalyser test was conducted correctly, or want to establish whether the result can be challenged, it is worth discussing the matter with a lawyer.
It pays to be properly prepared: both in knowing what you can claim and in having a clear strategy.
We handle cases for drivers in Poznań and across the Wielkopolska region, with in-person and online consultations available for clients elsewhere in Poland.
Adwokat Marta Krzyżanowicz and Adwokat Michalina Koligot Law Firm “Adwokat dla Kierowców w Poznaniu”
ul. Adama Mickiewicza 18/3, 60-834 Poznań
tel. +48 795 001 536 · +48 531 335 713
kontakt@adwokatdlakierowcy.pl · www.adwokatdlakierowcy.pl
This text is for general information purposes only and does not constitute legal advice. Every case requires individual analysis.
