In this article, Gordon Tranter and Alec Horner look at the legal information related to drug and alcohol testing at work, in a transport-related context, and include some of the issues involved in creating a drug and alcohol policy.


Employers have a general duty under the Health and Safety at Work, etc Act 1974 (HSWA) to ensure, as far as is reasonably practicable, the health, safety and welfare of employees. If an employer knowingly allows an employee under the influence of drugs or excess alcohol to continue working, and this places the employee or others at risk, they could be prosecuted. Similarly, the HSWA requires employees to take reasonable care of themselves and others who could be affected by what they do.

The Management of Health and Safety Regulations 1999 state that employers must carry out risk assessments for all significant activities of their employees and for those affected by their work activities (ie the public and their customers).

The Corporate Manslaughter and Corporate Homicide Act came into force on 6 April 2008 and could be used against employers who fail to take reasonable steps to ensure that their employees are fit to carry out their duties, particularly with regard to public safety.

The Misuse of Drugs Act 1971 covers nearly all drugs with misuse and/or dependence liability. The Act makes the production, supply and possession of these controlled drugs unlawful except in certain specified circumstances. If an employer knowingly permits the production or supply of any controlled drugs and the smoking of cannabis or certain other activities to take place on their premises, they could be committing an offence.

The law on testing for alcohol and drugs at work

Drug and alcohol testing can be highly controversial, and raises issues of privacy and human rights. Employees cannot be forced to take drug and/or alcohol tests unless it is a condition of their employment and is set out in their contract of employment, or if they have given their consent. Obtaining samples without consent could constitute the criminal offences of assault or battery. Employers who carry out unnecessary tests could be open to legal challenge, particularly under the Human Rights Act 1998, which includes the right to respect for private and family life and home.

Testing in safety critical industries

Drug and alcohol testing should be carried out on employees carrying out jobs in which impairment due to drugs or alcohol could have disastrous effects for the individual, colleagues, members of the public and the environment, eg drivers and mechanics operating workshop machinery.

The Transport and Works Act 1992 makes it a criminal offence for certain workers to be unfit through drink and/or drugs while working on railways, tramways and other guided transport systems. The operators of the transport system would also be guilty of an offence unless they had shown all due diligence in trying to prevent such an offence being committed. The Road Traffic Act 1988 states that any person who, when driving or attempting to drive a motor vehicle on a road or other public place or when in charge of a motor vehicle on a road or other public place, is unfit to drive through drink or drugs is guilty of an offence.

Driver education and the driver CPC

The syllabus for driver CPC periodic training specifically details drug and alcohol awareness and this is an ideal opportunity for drivers to be educated about the effects and dangers of drugs and alcohol. Many drivers simply do not understand the effects that drinking can have nor the dangers of excessive alcohol in their body the “morning after” consuming alcohol. Furthermore, the danger of all drugs, including prescribed and “over the counter” medicines, besides illegal drugs, needs to be adequately explained.

HSE guidance

The HSE guidance INDG382 Driving for work — managing work-related road safety also states that employers should ensure that their drivers are fit to drive.

VOSA/Traffic Commissioners

The Safe Operator’s Guide (revised 2008) explains the advice from VOSA and the Traffic Commissioners to operators, and states: “We recommend that you introduce random alcohol and drugs testing and develop such a policy in consultation with the workforce/trade union. When setting your policy for alcohol testing you should decide whether to use the UK legal limit or the lower limit considered safe in most European countries. Drivers who start work early in the day are particularly at risk of having excess alcohol left in their system from the night before.”

The Traffic Commissioners may require operators to submit written evidence that they have effective drugs and alcohol policies in place.

Random testing

Drug testing should only be introduced following proper consultation with staff and their representatives and should be even-handed. The Health and Safety Executive (HSE) recommends, in INDG 240, that for alcohol screening, “in addition to changes to the contract of employment, you should obtain the written consent of the individual for each test”. The employer needs to demonstrate that testing for drugs and/or alcohol is necessary to combat risk and is limited to those employees that need to be tested to deal with a specific risk. The employer must obtain informed consent from an employee before carrying out a drug test.

An employer could be liable to prosecution under the Equality Act 2010 for targeting drug testing at a particular group or for implementing drug testing in a discriminatory way. Selection for testing must be genuinely random.

Practicalities of drug and alcohol testing

The evidence for a link between drug or alcohol use and accidents is quite conclusive and alcohol testing is relatively straightforward and speedy to administer, with the time taken to carry out a breath test being measured in seconds.

Therefore, alcohol testing with a breathalyser causes minimal disruption to transport operators, although it can be more difficult to carry out with remote drivers who do not normally report to a fixed depot location, although Alco-locks can overcome such issues.

Drug testing is more complex and a relatively lengthy procedure, taking around 20 minutes per test. This can make it difficult to carry out testing when drivers report for duty without causing disruption to schedules. Although up to 20% of drivers involved in fatal accidents have drugs in their bodies (both legal and illicit) other factors have often been linked to these accidents, such as impairment through alcohol.

Cheating the urine test

There are numerous strategies used by cheats for passing a urine drug test, which is the most commonly used method of testing. This can be achieved by substitution, dilution or the addition of adulterants, including so called “masking agents” sold commercially. The use of adulterants can cause false negative results in drug tests by either interfering with the screening test and/or destroying the drugs present in the urine.

Alco-locks and breathalyser kits

Some transport operators are now fitting Alco-locks to vehicles, which entail drivers breathalysing themselves before starting a vehicle. This system is often linked to a remote monitoring system, which alerts a central control point if a driver fails a breath test.

Alco-lock systems are now mandatory in some EU countries (eg for French-registered PCV coaches) or are factory-fitted as standard equipment (eg for new trucks in Sweden).

From 1 July 2012, all foreign drivers travelling into France (lorries, coaches and buses, as well as cars) must carry simple disposable self-breathalysing kits in the vehicle (effectively two kits in case one is used), which conform to the Norme Française (NF) standard.

All commercial drivers (eg lorry drivers) should carry 0.05% BAC kits.


Companies that are concerned about alcohol or drugs in the workplace should have a drugs and alcohol policy which contains a clear outline of the aims and purposes of the policy and set out the rules and procedures around alcohol and/or drug use. The policy on testing should:

  • outline who is covered by the policy and whether a particular group (eg employees carrying out safety-critical work) is subject to tighter restrictions

  • outline what constitutes misuse

  • outline the testing procedure and why the test is necessary

  • outline what happens if a test proves positive and the disciplinary action that may be taken.

The policy should be developed in consultation with staff and union representatives.

Data protection of drug and alcohol testing results

Information about an employee's health, which includes the results of alcohol and drug testing, is sensitive personal data. Employers must, therefore, ensure they adhere to the Information Commissioner's Code of Practice when carrying out drug or alcohol testing to avoid breaching the Data Protection Act 1998. The results of a drug test must remain confidential, even if the test is failed.


If an employee fails an alcohol or drugs test, the employer may be able to dismiss them summarily for gross misconduct, particularly if they work in a safety-critical profession and their drug use has noticeably impacted upon their job performance. However, the employer should always ensure that it follows the Acas Code of Practice on Disciplinary and Grievance Procedures, together with any of its own policies and procedures, before taking a decision to dismiss. Failure to follow the Acas Code of Practice is not an offence, but employment tribunals will take the Code into account when judging whether a dismissal was fair or not.


Alcohol and drug testing is widely used in safety-critical and other occupations where the public is entitled to expect the highest standards of safety and probity. In addition to their purpose of preventing accidents, these tests have the added advantage of maintaining public confidence.

Testing must take account of legal considerations and be either a contractual requirement or carried out with the employees’ consent. The testing should be limited to the employees who need to be tested to deal with the risk and should not be discriminatory. Random tests should be genuinely random.

If such testing is to be used, it should not be implemented as a stand-alone approach. It should be incorporated as part of a comprehensive program for workplace alcohol-and drug-related harm.

Last reviewed 27 March 2012