The Difference Between An Alcohol Interlock & A Breathalyser

Drink driving continues to be a serious issue in Australia, contributing to approximately 30% of fatalities each year. With strict laws in place and lives on the line, monitoring alcohol levels before getting behind the wheel is more important than ever.

When it comes to alcohol detection tools, two devices are commonly used: alcohol interlocks and breathalysers. While both serve to detect alcohol in a person’s system, their functions, legal uses, and applications are quite different.

As a trusted provider in the field, Guardian Interlock helps Australian drivers meet their legal obligations through reliable, court-approved alcohol interlock systems, offering a pathway to safer roads and second chances.

What Is An Alcohol Interlock Device?

An alcohol interlock device is a specialised breath testing unit that is hardwired into a vehicle’s ignition system. Its purpose is simple but powerful: to prevent someone from starting their care if alcohol is detected on their breath.

Before the engine starts, the driver must blow into the interlock. If the device detects alcohol over the registered limit, the vehicle won’t start. Some systems also require random retests while driving to ensure the driver remains alcohol free behind the wheel.

Alcohol interlocks are commonly mandated by the court systems for drivers with drink driving offences. They’re also used in rehabilitation programs and by some companies as part of employee or fleet safety policies.

Their goal is to not restrict driving but to encourage behaviour change, reducing repeat offences and keeping roads safer for everyone.

What Is A Breathalyser?

A breathalyser is a device designed to measure the amount of alcohol in a person’s system by analysing their breath. It’s commonly used in a variety of settings such as by individuals for personal safety, employers for workplace testing, and most notably, by police for roadside enforcement.

Breathalysers work by detecting Blood Alcohol Concentration (BAC), the key metric used to determine intoxication levels. When you blow into the device, it captures a sample of your breath, which contains alcohol vapour from your lungs. This vapour is then measured using sensors that calculate your BAC and determine if you’re over the legal limit.

There are two main categories of breathalysers: portable and professional-grade.

• Portable breathalysers, typically used by individuals, offer quick readings and are convenient for personal checks before driving. 
• Professional models, like those used in law enforcement or workplace settings, are far more accurate and often feature advanced calibration, data logging, and integration with safety protocols.
  

While both types aim to promote safety, the key difference lies in their accuracy, reliability, and legal standing in enforcement situations.

Key Differences Between An Alcohol Interlock & A Breathalyser

When Is An Alcohol Interlock Required?

If you’ve been convicted of a high-range, repeat, or aggravated drink driving offence, most states and territories will mandate an alcohol interlock program as part of your licence reissue conditions. These programs typically require a participant to install an interlock in their vehicle for a minimum period (e.g., 3-48 months), and only drive vehicles/nominated vehicle fitted with the device.

Common legal triggers for an alcohol interlock include:

• Driving with a BAC of 0.05 or above
• Repeat drink driving offences
• Refusing to submit to a breath test
• Drink driving while on a learner or provisional licence

During this mandated period, you must provide a clean breath sample before starting your car. Mandated interlocks also require random retests when driving, and failed attempts are logged and reviewed by authorities. This can lead to an extension of the interlock program.

While a breathalyser helps you make informed decisions, an interlock is about compliance and accountability, designed to keep repeat offenders off the road unless they’re sober.

Why Choose Guardian Interlock?

When it comes to choosing an alcohol interlock provider, Guardian Interlock stands out for our commitment to making the process as smooth and supportive as possible. As an accredited Australian provider, we offer a nationwide network of installation locations, ensuring easy access wherever you are. From the moment your device is installed, you’ll have the backing of a dedicated team who manage all monitoring requirements and provide ongoing customer support, so you’re never left navigating the process alone.

We also understand the importance of moving forward. That’s why we make licence restoration fast and hassle-free, with a streamlined removal process once your program requirements are met. More than just a provider, Guardian Interlock is your partner in regaining independence safely and responsibly. Whether you’re just starting your interlock journey or nearing the finish line, we’re here to support you every step of the way.

Stay Safe & Drive Responsibly

While both alcohol interlocks and breathalysers serve to reduce drink-driving, it’s important to recognise their different roles—one is a legal requirement, the other a personal safety tool. Whether you’re navigating the conditions of a court or voluntary program, or simply looking to make safer choices behind the wheel, understanding your options is a vital part of protecting yourself and others on the road.

At Guardian Interlock, we’re here to help drivers meet their legal obligations and regain their independence with confidence. If you have questions about installation, monitoring, or program requirements, our friendly team is ready to assist. Email admin@guardianinterlock.com.au or call 1300 881 005 today to get started.