In the first part of two articles, Gordon Tranter examines the pros and cons of alcohol and drug testing in the workplace as well as looking at some of the practicalities involved.

Drugs and alcohol abuse can significantly weaken business performance, through loss of productivity, poor staff performance, lateness and absenteeism, safety concerns, the effect on team morale and employee relations, bad behaviour or poor discipline, and adverse effects on company image and customer relations. Drug and alcohol misuse is currently costing UK industry an estimated £12–16 billion every year in workplace accidents, claims for compensation, ill health, absenteeism, reduced productivity and criminal activity. Consequently, testing employees for alcohol and drugs is capturing the interest of an increasing number of employers. However, drug and alcohol testing is a legal minefield and the effectiveness of drug testing is uncertain. This report outlines the pros and cons of alcohol and drug testing, the legal constraints and the screening procedures available.

The problem

The effects of alcohol at work

There are three main ways in which alcohol can have detrimental effects in the workplace.

  • A raised blood alcohol level while at work jeopardises both efficiency and safety; it increases the likelihood of mistakes and errors of judgement, increases accident prone-ness and impairs skills.

  • The after-effects of drinking (hangovers) can reduce concentration and cause inability to work at a normal pace. Workers complaining of hangovers may absent themselves from the workplace.

  • Persistent heavy drinking can lead to a range of social, psychological and medical problems, including dependence, and is associated with impaired work performance, increased sickness absence and interpersonal difficulties.

The extent and consequences of alcohol abuse in the workplace

A survey carried out in December 2007 for Norwich Union Healthcare found:

  • a third of employees admitting to having been to work with a hangover

  • 15% of employees reporting having been drunk at work

  • 10% of employees reporting hangovers at work once a month

  • 5% of employees reporting hangovers at work once a week.

The majority (77%) of employers interviewed for this survey identified alcohol as a major threat to employee wellbeing and a factor encouraging sickness absence. A survey carried out by YouGov for PruHealth found that each day around 200,000 British workers turn up to work hungover from the night before.

It is estimated that 17.3 million working days are lost through alcohol misuse, costing about £1.8 billion every year. (Alcohol and the workplace? The importance of early intervention and workplace policies in reducing the health and business impact of alcohol misuse (2011).) The National Social Marketing Centre estimated that alcohol misuse cost employers £7.3 billion in 2007.

The effects of drug misuse in the workplace

Of the working age adults in England and Wales, 8.6% used drugs in 2009–2010; 3.1% used Class A drugs and 6.6% used cannabis. The figures for young adults (16–24) are significantly higher.

There are well-documented links between drug use and impairment of cognition, perception, and motor skills, both at the acute and chronic levels. Drugs can change the way a person thinks and feels, which can lead to poor judgment or concentration. A person whose work performance is being affected by drug abuse can pose a risk to their own and other people’s health and safety. There is a potential for causing accidents, poor work performance, reduced productivity, lateness, increased sickness absence, a hostile work environment and damage to an organisation’s reputation. These adverse effects can occur even when the misuse takes place outside the workplace.

There is a shortage of quality evidence on the impact of drug-related harm in the workplace, probably because there are a large number of different drugs with a wide range of potencies, effects and patterns of consumption. However, the available evidence indicates that drug-related harm in the workplace should be treated as a serious issue.

The National Clearinghouse for Alcohol and Drug Information stated that in the United States:

  • 10% of drug users had missed work due to a hangover

  • 6% had gone to work high in the last year

  • 18% of drug users had skipped work due to their habit in the past month.

The scale and impact of illegal drug use by workers, a report for the HSE by the Centre for Occupational and Health Psychology, Cardiff University (2004), found:

  • an impact of drug use on cognitive performance, varying with the type of drug or drugs used

  • this impact on cognitive performance being mirrored by an association with cognitive failures at work

  • no association between drug use and workplace accidents, though associations did exist between cannabis-only use and work-related road traffic accidents among those also reporting higher levels of other associated risk factors

  • an association between drug use and minor injuries among those who are also experiencing other minor injury risk factors.

The report concluded that the lack of association with work accidents may be either because no association exists or because the number of accidents studied was too small for a significant association to be detected.

Another factor that needs to be considered is the mounting evidence that harmful substance use is one of a range of behaviours exhibited by certain individuals who may avoid work-related safety precautions and take greater work-related risks.

Only a minority of drug-related injuries actually occur at work; generally these accidents happen during leisure hours. However, they can still reduce attendance.


Testing employees for alcohol and drugs is being considered by an increasing number of employers as drugs and alcohol become more prevalent in the workplace. Drug and alcohol testing is already common in the United States of America where, over the last 30 years, pre-employment and random drug and alcohol testing has become a multi-million dollar business with an estimated 70% of all US companies testing for drugs.

In the United Kingdom, between 200,000–300,000 tests are carried out each year, mainly in safety critical industries that involve security (armed forces, prison service) and transport (rail and underground drivers).

In general, alcohol and drug tests are divided into two groups.

  • Laboratory testing. The donor gives a sample of urine, blood, hair or saliva/oral fluid. After collection, the sample in a tamper-evident seal/integrity container is sent for laboratory analysis. The advantages of this type of test are accuracy, legal defensibility, and the ability to customise tests for a particular demographic group. The disadvantages are typically the costs associated with the need for collection sites (urine, blood), the costs of the analysis and the delay in receiving results (up to 5 days).

  • On-the spot, on-site screening. This form of screening uses an inexpensive kit, which provides results within minutes. Besides urine, which can use a test cup that collects and detects in the same container device, saliva or sweat are used in on-site testing.

Samples should be collected under supervised conditions that respect human dignity. They should be collected under a chain of custody, ie in a tamper-proof sealed container in the employee’s presence and handled and stored carefully, so that the test results can be fully relied upon in court. Any positive results from on-site screening should be confirmed by a technique that identifies the specific drug or metabolite, usually gas chromatography/mass spectrometry. Two identical samples should be taken either on-site or split in the test laboratory and the second sample kept for further analysis as part of any appeal by the employee.

Although not a legal requirement, the laboratory used to analyse samples for drugs or alcohol should be accredited by the United Kingdom Accreditation Service (UKAS), which assesses the competence of the technical and managerial aspects of the screening and testing services provided by laboratories.

Alcohol testing

Alcohol testing is relatively straight forward. The level of impairment is linked to the dose. Road accidents are statistically linked to drink driving, for which there are limits (80mg/100ml blood).

There are many different forms of screening for alcohol. On-site screening can use:

  • breath testing

  • saliva testing: using a swab colorimetric method

  • urine testing: using a dipstick.

Urine and blood analysis can also be analysed for alcohol in a laboratory, usually to confirm on-site screening results in case of disciplinary or legal action.

Drug testing

On-the-spot drug screening is carried out on the three kinds of samples.

  • Urine samples. These are commonly used as they are non-invasive, easy to store and process, and will give a result in five minutes or under. Urine specimens are representative of the drugs that have been taken in the past few hours. Results can be confirmed in the laboratory if steps that could result in a legal action are taken.

  • Saliva tests. These are designed to simplify the sample collection process and allow the sample collection process to be fully observed, and are consequently thought to be less amenable to adulteration than urine. The results from saliva tests are close to the level of drugs found by blood tests.

  • Sweat testing. This is non-invasive, and is limited as it is difficult to obtain a sufficient amount on which to conduct an initial and a second confirmatory test.

These screening tests are designed to detect a specific number of drugs or drug classes, eg amphetamines, benzodiazepines, cannabis/marijuana (THC), cocaine, methamphetamines (including ecstasy/MDMA) and opiates (including heroin).

Drug tests on hair samples are carried out in a laboratory. In contrast to urine, oral fluid and sweat drug tests, which reflect recent exposure, hair testing is about past drug misuse over periods of time from weeks to many months. Blood is not commonly analysed for drugs, because the levels of drugs in the blood are low compared with urine.

Performance testing

Functional performance testing — tests that require the employee to complete a series of activities to detect impairment — have the potential of testing safety-sensitive employees for impairment, whether from drugs, alcohol, anxiety, stress or fatigue. Care must be taken to ensure that testing methods are minimally intrusive and reliable, that the test is standardised and that it does not have any inherent biases, eg against women or visible minorities. The impairment test must be demonstrably connected to the performance of the job, eg if an employee occupies a safety-sensitive position, or after significant accidents or “near-misses”, or if there is reasonable cause to believe that a person is abusing alcohol or drugs and only then as part of a larger assessment of drug and alcohol abuse.

Medical review

Some legally available drugs are capable of producing a positive test for illicit substances. In order to avoid falsely accusing an employee of illicit drug use, it is essential that a proper evaluation of a positive test result is carried out in light of the employee’s medical history, while protecting his or her privacy is essential.

In part two of this article, the author will discuss the legal aspects of testing.

Last reviewed 21 February 2012