How Does A Breathalyser Alcohol Tester Work?

If you're responsible for workplace safety, on a construction site, in logistics, public transport, or manufacturing, you've likely wondered: how do breath alcohol testers actually work? How accurate are they? And which model is right for your business?

This blog breaks down how workplace breathalysers function, the difference between active and passive testing, and what to consider when choosing a professional device like the Dräger Alcotest® 6000 or the Intoximeter Alco-Sensor FST.

What Does A Breathalyser Do?

A breathalyser measures the concentration of alcohol in a person’s exhaled breath, then uses that to calculate their Blood Alcohol Concentration (BAC). The result is typically shown on a digital display within seconds.

In a workplace context, speed and hygiene matter, especially when testing multiple staff across shifts. That’s why professional units use fuel cell (electrochemical) sensors, the same trusted technology used by police and transport authorities.

Devices like the Dräger Alcotest® 6000 and Intoximeter Alco-Sensor FST are designed for fast, accurate results, even in outdoor or high-traffic settings.

What’s The Difference Between Active vs Passive Breath Alcohol Testing?

Most workplace breathalysers support two modes:

Active Testing

This is the standard method. The employee blows into a disposable mouthpiece, and the unit provides a precise BAC reading. It’s suitable for:

• Random or scheduled workplace screening
  
  

• Pre-employment tests
  
  

• Post-incident investigations

Passive Testing

This involves detecting the presence of alcohol in the air near the subject, often without a mouthpiece. It's useful for:

• Quick screening in queues
  
  

• Identifying alcohol presence without requiring full cooperation
  
  

• Reducing single-use plastic mouthpieces

Devices like the Alcotest® 6000 offer both options, so you can adjust your approach as needed.

How Accurate Are These Devices?

Modern workplace breathalysers, like those from Dräger and Intoximeter, typically measure BAC to within ±0.01%, assuming:

• Proper calibration (every 6–12 months)
  
  

• Use of new, sealed mouthpieces
  
  

• Adherence to warm-up and environmental guidelines

The Intoximeter Alco-Sensor FST, for example, uses a fuel cell sensor that resists false positives from environmental factors and gives consistent, court-admissible results.

How Long Does A Test Take?

Time matters when you're testing multiple staff.

• Power-on to ready: under 30 seconds
  
  

• Blow-to-result: 3 to 25 seconds depending on alcohol level
  
  

• Device reset: typically 20 to 120 seconds

This makes both the Alcotest® 6000 and Intoximeter suitable for high-throughput environments like warehouses, depots, or events.

Why Are Businesses Using Workplace Breathalysers?

Workplace alcohol testing is a duty of care. For industries where impairment can put people at risk, quick, verifiable testing supports:

• Safer working conditions
  
  

• Compliance with HSE, FORS, Network Rail, or internal safety policies
  
  

• Consistent enforcement of drug & alcohol policies
  
  

• Post-incident documentation
  
  

• Insurance and audit requirements

Random, routine, or post-incident testing depends on your internal policies, but the goal remains the same: to keep everyone safe.

What Should You Look For in a Workplace Device?

Here’s a breakdown comparing features useful for professional settings:

Both the Dräger Alcotest® 6000 and Intoximeter Alco-Sensor FST meet these needs, your choice may come down to user interface, reporting preferences, or budget.

How Does a Breathalyser Work, and Which One Should You Use at Work?

In simple terms, a breathalyser detects alcohol in a person’s breath to estimate their blood alcohol concentration. But in a workplace context, the how matters far less than the why.

Professional devices like the Dräger Alcotest® 6000 and Intoximeter Alco-Sensor FST are designed not just for accuracy, but for speed, hygiene, and compliance. They’re used by businesses that need to test quickly, repeatedly, and with confidence, whether that’s on a construction site, at a depot gate, or after an incident.

If your staff operate machinery, drive, or work in public-facing roles, alcohol testing isn’t overkill, it’s part of your legal and moral responsibility. And having the right device on hand helps you meet that responsibility safely, fairly, and efficiently.