What’s Your Score?

Dozens of health-conscious people ‘know their numbers’ after visiting Express Medicals’ stand at this November’s CIPD show in Manchester.

Sales team Mat Gilliver and Sam Bennett were joined for the two-day event by one of our nurses, Haley Young, to welcome visitors to our stand.

Those keen to find out more had a basic health check, with the team on hand to explain how simple medicals and fuss-free testing can help companies to create effective and efficient occupational health strategies for every member of staff. We were promoting our ‘Know Your Numbers’ tests, which collate blood pressure, cholesterol, blood sugar and other scores to help identify trends in staff health.

“We had a really enjoyable show and were able to meet dozens of people, keen to talk about the hot topics in occupational health,” explained Mat Gilliver, Express Medicals’ Sales Manager. “We talked about current best practice and have already had follow-up requests for meetings, with companies who want to continue those conversations.

“We’re a UK-owned and operated company which is tried and trusted in our field. Our ‘Know Your Numbers’ testing was popular, and we had lots of enquiries about our drug and alcohol testing too. Visitors certainly enjoyed the chance to chat with qualified medical staff on the stand and CIPD’s excellent logistics support meant we could concentrate on meeting and talking to visitors during the event.”


Know Your Numbers

– Express Medicals encourages exhibition visitors to take a health MOT –

Our nursing and sales staff will be out in force at this year’s CIPD annual conference and exhibition in Manchester on November 8 and 9, 2017.

This year’s show is themed around ‘embracing the new world of work’. Part of that new world can include increased levels of stress leading to mental health issues or busy lifestyles affecting physical fitness.

We’ll be encouraging visitors to have a quick blood pressure test administered by one of our friendly, professional nurses.

We’ll also be discussing our popular ‘Know Your Numbers’ service, which offers companies of all sizes the chance to gain an overview of cholesterol, BMI, blood pressure and blood sugar levels across the company, to help plan successful occupational health strategies.

Come and visit us on stand G64.

Roadside Breathalyser

This month marks the 50th anniversary of the first roadside use of the breathalyser.

 Express Medicals’ scientific advisor, Dr Simon Davis BSC PhD explores the history of this ground-breaking technology that’s trusted by the courts.

 50 years of alcohol breathalysers – an occupational health revolution

The use of drugs in modern society is generally seen as socially unacceptable, yet one drug is openly used and readily available: alcohol.

Its effects are well-known, ranging from a relaxing soporific glow to violent and uncontrolled eruptions when consumed in excess.

The choice of whether, and how much alcohol, to drink could be seen as a personal choice. But when that behaviour is embedded in a workplace, the use of alcohol can and has had fatal consequences. The depressive effects of alcohol impair both mental judgement and physical co-ordination, something to be avoided at all costs when operating machinery, driving or undertaking any safety critical activity.

Where it all started

The effect of alcohol in the workplace has been a problem for many years, some of the first UK drink driving regulations actually date back to 1872. The Licensing Act, made it an offence to be in charge of a carriage or horse whilst under the influence of alcohol. The first conviction followed shortly after, in September 1897 when George Smith was fined 25 shillings for being intoxicated while in charge of a horse-driven London taxi.

Such legislation was welcome, but the lack of any method to measure the amount of alcohol a person had consumed meant the way the law was applied was open to abuse and highly subjective.

Chemistry verses alcohol

Scientific knowledge around this period was sufficiently advanced to know that alcohol within the body was equally distributed through all fluid compartments. This meant that the amount of alcohol in the blood, urine and saliva would be proportionately equal to one another. Armed with this knowledge, US doctor Dr Emil Bogen published a landmark study on the relationship between alcohol within blood and exhaled breath. The 1927 paper conclusively showed that although the amount of alcohol in breath was far lower than that of the blood, it was directly proportional. In other words, blood alcohol could be directly calculated from breath alcohol.

The method Bogen used to measure breath alcohol was a wonderful yet simple chemical process that any high school student could now repeat. He placed a small amount of sulphuric acid and potassium dichromate into a football bladder. The person being tested would then breathe into the bladder and, if alcohol were present, the crystals would change colour. The degree and hue of colour change provided an estimate of the amount of alcohol within the breath. This beautiful reaction worked exceptionally well but wasn’t practical for roadside or workplace testing.

Due to the potential of Dr Bogen’s method it wasn’t long before the first usable breathalyser had been developed. The aptly named Drunkometer first went on sale in 1936 developed by Professor Rolla Neil Harger at the Indiana University School of Medicine.

The Drunkometer worked on a similar principle to Dr Bogen’s system. Breath was passed through an acidified solution of potassium permanganate. The presence and approximate concentration of alcohol was indicated by a change in colour.

The first commercially available breathalyser known as the Drunkometer (Indiana 1936)

Although available to the UK market, the Drunkometer was never seriously adopted by the British police or regulatory authorities. The identification of inebriation was left to subjective sobriety tests.

Lab coats and legislation

Little changed until January 1966, when Parliament introduced the Road Safety Bill. Among other regulations, the first formal imposition of a maximum blood alcohol level was set: 80mg of alcohol in 100cc of blood. Concentration of alcohol above this level constituted an offence. This landmark legislation meant that, for the first time, intoxicated drivers could be identified and prosecuted with confidence and fairness. Things had come a long way since the 1897 conviction of George Smith.

The following year, Barbara Castle, then Minister for Transport, introduced the 1967 Road Safety Act that included approval of roadside portable breathalysers. The effect of the Act combined with active enforcement by the police was almost instantaneous, reducing road accidents by a full 10% in the following year.

Into The Modern Age

Alongside legislative changes, 1967 saw the development of the first electronic breathalysers. Tom Parry (UWIST) and electrical engineer Bill Ducie designed the prototype system in Cardiff. The two engineers went on to form Lion Laboratories and designed many of the workhorse devices commonly used over the past 50 years.

Modern day occupational health and police testing programmes have a wide range of devices to choose from. Despite this, some providers still opt for ‘Colormetric’ detectors. These units use Bogen’s 1927 technique and depend on the operator observing the changes in colour of potassium-dichromate crystals, hence the title Colormetric. These devices are cheap and have some functionality but fall short of the precision and reliability needed to comply with modern day evidentiary standards.

Currently one of the most accurate portable breathalyser technologies is the Infrared or IR analyser. These units work by passing a beam of IR light through a stream of breath gas. The IR is made up of many different wavelengths most of which pass freely through the breath. However, certain wavelengths of IR light are absorbed by alcohol. The more alcohol present, the more IR light is absorbed. A small detector opposite an IR source quantifies the amount of absorbance as the light passes through the sample breath stream. This in turn is used to calculate the presence or absence and concentration of alcohol. This process is highly accurate, typically reporting breath alcohol concentrations to within 0.2g/l (200 ppm).

As IR systems have no moving parts they tend to be extremely stable requiring calibration only once a year or less. IR technology also results in highly specific systems that do not provide false readings resulting from interference from other products. A good example of this is the chemical acetone. This chemical can be produced within the body when someone is dieting. It has been shown in a number of studies that acetone produced in this manner can cause less specific breathalysers to report false positives. Although confirmatory testing normally identifies this error the subject will be exposed to significant unnecessary stress.


Can I fool a breathalyser?

Many myths circulate about how you can turn up roaring drunk for an alcohol test, pop some gadget in your mouth and expel pure scented breath without a drop of alcohol present. There may have been a spark of truth to these rumours in some of the early devices, but a modern IR-based breathalyser will reveal all your alcohol sins. Popular myths include putting copper coins under your tongue, eating onions and drinking mouthwash. None of these will have the slighted effect – except mouthwash. Mouthwash is an exception as it will generally contain alcohol and would probably increase your reported alcohol levels significantly. Certain mouthwash products contain upwards of 30% alcohol.

Breathalysers have come a long way since their first inception as an acid-filled football bladder. They are now highly specific and accurate devices that can be reliably deployed at the workplace or on the roadside. Their results are consistent and dependable and are regularly used as definitive evidence in civil and criminal court cases.

Without doubt, the not-so-humble breathalyser has prevented countless accidents and saved many lives.

Happy 50th anniversary!

Dr Simon Davis is a senior research scientist at Imperial College in the Faculty of Earth Science and Engineering