News | April 16, 2020

Cleaning up construction sites. How to avoid the hangover when implementing testing for alcohol and drugs Drug testing your employees

The construction industry is a sector in which research suggests that the use of drugs and alcohol is prevalent and this creates a high risk environment because employees acting under the influence can cause catastrophic harm.

Why is drugs and alcohol a risk to the construction industry?

In 2015  the Considerate Constructors Scheme surveyed over 1,300 people working across the industry which found that 35% of respondees had noticed that their colleagues were under the influence, and  that 65% have never been tested for drugs and alcohol.

Employers have a duty under the Health and Safety at Work Act to provide a healthy and safe working environment. A failure to provide such an environment could also lead to claims by employees for personal injury. A record for poor health and safety will also damage the employer’s reputation.

Justification for drugs testing

In this context it might seem like a straightforward decision for a business to implement drugs and alcohol testing on employees. However, carrying out such tests on your employees is not necessarily easy to implement. There are various considerations that need to be taken into account. It is important to remember that generally there are relatively non-invasive tests for alcohol – eg: breathalyzer – but for drugs the testing can be much more invasive – blood sample or hair pull.

The justification for drugs’ testing employees is one of the critical issues that needs to be considered. For example, whilst it may be that construction is an area where health and safety is vital, it may not be necessary or justifiable to test  all roles, including those which are not health and safety critical.

You also need to consider when the drug testing will be implemented. Will it be only where there is a suspicion that someone may be  intoxicated? Or is random testing necessary? It is important to make sure that there are policies and procedures which are in place and of which the employee has been made aware to help justify such testing.

The mechanics of drug testing

There are various drug testing companies offering their services and it is important to choose a reputable company. There have been recent cases where an employee has been dismissed by an employer for a positive drugs test, but it has been held by the tribunals that the manner of the testing was not foolproof and that the employer should have explored other means of testing to support the positive result before a dismissal. Therefore, it is important to make sure that you have experts who understand the issues at hand so that you can be properly advised on the technicalities of drug testing, particularly where any result may lead to disciplinary sanctions or dismissals.

Data Protection

One key area employers will also need to consider is data protection. As well as ensuring that there is a reasonable justification for subjecting the employee to testing (see above), the employer will also want to ensure that any processing of the employee’s data is carried out in accordance with GDPR/the Data Protection Act 2018, particularly since the data which may be held by the employer, as part of any processing, could form sensitive personal data which needs to be handled with the necessary enhanced levels of appropriate care.


It is essential that, after having considered the relevant factors (including those set out above) that an employer implements a policy and follows this consistently.

Therefore, whilst drug testing would seem to be a useful tool in the construction industry to help manage their workforce, comply with statutory obligations concerning health and safety and protect their reputation, any such policy needs to be given serious thought before it is introduced.