Testing for alcohol is relevant as alcohol is the most commonly abused drug in the UK. Alcohol is unique in the fact that it is volatile enough to be detected on expired breath. Alcohol use can be detected and recorded in a number of ways including the detection of previous regular use via hair analysis. The most common of these is testing for alcohol via a “breath test”. We can perform a test in a similar way to the police, on a roadside breath test on suspected drink-driving.
Testing for alcohol in breath can be taken in isolation, or routinely performed alongside a drug test. There are a number of solutions to testing for alcohol in a breath sample.
- Some qualify results only – for example crystals changing colour in a tube when a “positive” breath sample is provided.
- Some quantify results – for example the breathalyser unit shows a reading (usually in BrAC – Breath Alcohol Content).
ITS Test Kits recommend a quantifiable breath test to ascertain alcohol levels in a person’s system.
There are many models of breathalyser in the UK marketplace, but again it really comes down to price versus quality. ITS Test Kits are an approved distributor and calibration centre for Intoximeters Inc. We recommend these breathalyser units due to reliability, accuracy, durability, credibility and value for money. They are UK Home Office approved and are used by many Police forces and organisations worldwide.
Testing for alcohol with personal breathalysers, like the cheaper “Alcometers”, is mainly based on semi-conductor sensor technology. Devices are designed, in principle, for use by a single, regular user. It is assumed that the user is a willing participant and trying to get an accurate, consistent sample. They are not trying to “fool” the machine by varying the way they blow, using mouthwash or any other means to avoid an accurate reading.
These personal breathalysers can be a very effective and useful device provided the user:
- ensures that every time they use the device they blow in the same manner,
- that they always take the average of 3 readings (ignoring any spurious results) and,
- most importantly, use the device primarily to determine how long it takes them to return to zero.
With regular use the user will know roughly what result to expect for a given consumption. They will also therefore be aware if/when the readings start to become unreliable. The person doing the testing has no idea what to expect when testing someone else. The tester is obvious and unaware of the consumption of the person being tested. Therefore they cannot know whether the device is giving an expected, or spurious, result.
Semi-Conductors can be very accurate around their calibration points (usually 0.03% & 0.10% BAC) but outside of this can start to vary by a greater degree. Again, for personal use in determining how long it takes to return to zero this is not a problem, but it can make any single specific reading less reliable. Samples are only measured based upon a set time (and sometimes minimum pressure) but the actual volume can be varied considerably should the user choose to do so. Replacing parts and sensors is the only way to re-calibrate these devices.
Professional breathalysers (like the Intoximeter FST) are specifically designed for testing for alcohol in other people. They measure a volume sample (usually around 1.7ltrs) irrespective of how long or how hard a person blows. They are based upon an ElectroChemical Fuel Cell rather than a semi-conductor sensor.
These platinum based fuel cells give an accurate reading throughout their range and are largely impervious to compounds other than alcohol. They are far more consistent and more resistant to contamination by excess alcohol. For instance by a test taken too soon after drinking and also to smoke particle contamination.
In most circumstances within the UK we would always recommend the use of a UK-certified device like the Intoximeter FST. Many UK and Worldwide Police forces currently use these UK Home Office type approved devices. These can and always should be, recalibrated to maintain reliability and legal defensibility.
It is now sufficient within the UK for employers to use the results of a breath test taken by a Home Office approved breathalyser (such as the Intoximeter FST with printer) as part of the disciplinary procedure.
The use of urine sampling for alcohol screening and/or confirmation is no longer considered advisable unless no other option is available as this must be done in a very controlled and specific manner to avoid false positives.