By adopting passive alcohol testing, organisations can:
- Accelerate employee screening — especially critical on zero-tolerance sites where every individual is tested daily.
- Reduce reliance on single-use plastic mouthpieces, lowering both cost per test and environmental waste.
- Minimise disruption and resource drain, streamlining safety procedures without compromising compliance.
What is Passive Alcohol Testing?
Passive alcohol testing is a contactless method of breath analysis. Instead of using a mouthpiece, the subject simply exhales, speaks, or breathes near the instrument, which draws in ambient air using an internal pump and analyses it for the presence of alcohol.
The pump may be activated manually by the operator or automatically via a pressure sensor that detects airflow across the inlet.
The Purpose of Passive Testing
Passive testing is designed to quickly confirm the absence of alcohol. It is not a substitute for standard (mouthpiece) testing, which provides a precise BrAC reading.
For Police and large workforce environments, passive testing enables rapid screening — allowing motorists and employees to be cleared and moved on with minimal disruption. In workplace safety contexts, it ensures individuals are alcohol-free before commencing their shift.
Accuracy vs Sensitivity
Passive alcohol testing indicates whether alcohol is present or absent in the ambient air around the instrument at the time of testing.
It’s important to understand that a positive passive test does not automatically mean the subject has consumed alcohol. The detected alcohol could originate from environmental sources. What matters most in passive testing is the sensitivity of the instrument — its ability to detect even trace amounts of alcohol in the surrounding air.
Unlike standard testing, which focuses on accuracy and quantifying alcohol levels in the subject’s breath, passive testing is designed to flag the presence of alcohol, regardless of its source.
High-quality breathalysers with passive mode functionality are engineered to maximise sensitivity. This ensures that if alcohol is present — from any source — the instrument will detect it.
Once alcohol is detected, the instrument signals the need for a follow-up test using a mouthpiece. This second test determines whether the donor is the source of the alcohol and provides an accurate reading of their Breath Alcohol Concentration (BrAC).
Reliability of Passive Testing
When conducted using a high-sensitivity instrument and by a trained operator following manufacturer guidelines, passive testing is highly reliable in:
- Confirming the subject is alcohol-free.
- Detecting the presence of alcohol in the surrounding air.
Pressure-Activated Passive Testing
Recent advancements have introduced pressure-activated passive testing, where the subject’s breath pressure automatically triggers the instrument to sample ambient air. This increases the likelihood that the sample reflects the subject’s breath, though environmental factors may still influence results.
Responding to a Positive Passive Test
In industrial settings, passive testing is a valuable first step in maintaining an alcohol-free workplace. However, a positive passive result should trigger secondary testing based on your workplace police and procedure. This is an example of a following protocol:
- Withholding Period
The subject waits 15 minutes under supervision (only water permitted). - Standard test
A mouthpiece test is conducted using an AS 3547-certified instrument to determine BrAC. - Interpretation
If the standard test shows zero alcohol, the passive result likely stemmed from environmental alcohol, not consumption.
Note – These are not “false positives.” A quality instrument detecting alcohol is almost always correct — the alcohol may simply originate from another source.
Passive Mode Sampling Cup
The passive mode sampling cup, available for the LE5 and HH4 breathalysers, enables fast, economical, and environmentally friendly testing. It features:
- Anti-blow-back protection
- Redirected breath flow away from both donor and operator
This supports safe, efficient alcohol screening in high-throughput environments.