What is an Éthylotest and How is it Used in France?

In France, an éthylotest (commonly referred to as a breathalyzer) is a diagnostic device used to determine if a driver has consumed alcohol beyond the legal limit. It functions by measuring the concentration of ethanol in a driver's exhaled breath. While these devices can be purchased for personal self-testing, they are also the primary tool used by law enforcement during routine roadside stops to conduct initial alcohol screenings.

There are two main types of breathalyzers used for screening:

• Chemical Breathalyzers (Éthylotests chimiques): These are single-use devices consisting of a tube containing chemical reagents (potassium dichromate) and a plastic bag (the balloon). The driver blows into the bag, and the air is pushed through the tube. If alcohol is present, a chemical reaction turns the yellow/orange reagent green.
• Electronic Breathalyzers (Éthylotests électroniques): These reusable digital devices use a sensor to analyze breath and provide a quick digital readout of whether the legal limit has been exceeded.

Legal Alcohol Limits on the French Code de la Route Exam

French road law enforces strict blood alcohol concentration (BAC) limits, which are heavily tested on the official Code de la route theory exam. The limits differ significantly depending on the driver's license status:

• Standard Drivers: The legal limit is less than 0.5 grams per liter (g/L) of blood, which corresponds to 0.25 milligrams per liter (mg/L) of exhaled air.
• Novice (Probationary) Drivers: For young drivers within their probationary period (three years for traditional licenses, or two years for those who completed accompanied driving), the legal limit is strictly less than 0.2 grams per liter (g/L) of blood, which is equivalent to 0.10 milligrams per liter (mg/L) of exhaled air. This limit is effectively a zero-tolerance policy, as even a single small alcoholic beverage can easily push a driver over this threshold.

Screening vs. Verification: The Legal Roadside Process

A crucial distinction in French driving theory is the difference between screening (dépistage) and verification (vérification):

1. Dépistage (Screening): Law enforcement uses a standard éthylotest to perform a quick initial screening. This test is binary—it only indicates whether the driver is over the legal limit (positive) or under it (negative). It does not provide a legally binding precise measurement.
2. Vérification (Verification): If the initial screening is positive, or if the driver refuses to blow, the police must verify the exact blood alcohol concentration. This is done using a highly precise calibrated machine called an éthylomètre (evidential breathalyzer) or through a medical blood test (prise de sang). The measurement from the éthylomètre is the official figure used to issue fines, deduct points, or suspend the license.

Ignition Interlock Devices (EAD) and Legal Consequences

An Éthylotest Anti-Démarrage (EAD) is an electronic breathalyzer wired directly into a vehicle's ignition system. Before starting the engine, the driver must blow into the device. If the recorded alcohol concentration exceeds the programmed limit (0.10 mg/L of air), the vehicle's starter is disabled, preventing the car from starting.

In France, judges or local prefects can mandate the installation of an EAD in an offender's vehicle as an alternative to a total license suspension following a drunk driving conviction. Furthermore, all public transport buses in France are legally required to be equipped with operating EAD systems to ensure passenger safety.

Mandatory Carriage Rules in France

For several years following a 2012 decree, French law required all motorized vehicles to carry an unused, unexpired breathalyzer. However, due to supply issues and reliability concerns, this regulation was modified over time. As of May 22, 2020, it is no longer mandatory to keep a physical breathalyzer inside your vehicle in France. Despite this change, self-testing remains highly recommended, and licensed establishments serving alcohol after midnight (such as nightclubs) are still legally required to make self-testing breathalyzers available to patrons.