Last week, a damning report alleged that workers on Tottenham Hotspur’s delayed new stadium were drinking alcohol and taking drugs whilst working on the construction of the 60,062-capacity project.

The allegations have created a PR nightmare for the construction firm mentioned in the report, so how can businesses stop the use of drugs on their work premises and if they suspect a worker of taking drugs on site can they legally drug test them?

Although there is no legislation which states that employers have the right to test employees for drug use, it is clearly recognised that certain job roles require this type of monitoring and therefore it is legal to carry out these tests. In particular, common areas where drug testing takes place is usually within industries where safety critical decisions need to be made, such as aviation, construction or medicine.

However, it is essential that employers maintain a written policy on the use of illegal substances within their workplace, specifying that employees may be subject to tests on occasion and outlining the consequences of being found to be under influence. Arguably, implementing a clear no-tolerance policy on drug use within an organisation can act as a strong deterrent to employees who are considering taking drugs and assist in maintaining a safe and secure working environment.

Employers can approach the testing process by conducting the check at random, taking care to maintain the unsystematic nature of random tests as unfairly singling someone out can lead to claims of discrimination. Drug tests can be undertaken in various ways including urine, blood, hair or saliva samples but should always be approached in a manner that assures the dignity and confidentiality of the employee.

If an employer has reason to suspect that an employee is operating under the influence, or has been involved in a work-related accident that raises concerns about their conduct, they can also seek to test them directly. Employees can refuse to be tested and this should not be processed as an automatic assumption of guilt, however wherever it is a contractual obligation to provide a sample the refusal should be dealt with via a disciplinary procedure. Employers may also allow the employee to be accompanied during the test.

If a test is returned with a positive result, employers should allow the employee the opportunity to offer an explanation. An employee taking medication prescribed by a doctor can sometimes give a positive result in a drugs test so it is important they determine the source of the result. Where the result is evidence of drug taking, they should deal with the employee through their usual disciplinary procedure and, in circumstances where this is warranted, dismiss the employee.

Results of a drug test will be classed as personal data in relation to the employee, so all information regarding the test should be stored in line with your data protection policy.