As an employer you have a legal duty to ensure, so far as reasonably practicable, the health, safety and welfare at work of all your employees. Equally, you are under a duty to protect the health and safety of visitors to your premises, as well as anyone else who may be affected by the work undertaken by your employees.
Both these duties include managing any heath and safety risks posed by employees who may be under the influence of drink or drugs whilst at work, or during working hours, or otherwise unfit to work through drug or alcohol misuse.
As an employer, you can also be prosecuted if you knowingly allow an employee to be in the workplace while they are under the influence of alcohol or drugs, or allow drug-related activities to go on at work and you fail to act on this.
It is important to remember that even where substance misuse takes place outside of work, the effects can persist long after the point of consumption, seriously impacting an employee’s performance at work by impairing their judgment and concentration. This means that you must take appropriate measures, where necessary, to ensure that your staff are not a danger to either themselves or others whilst working as a consequence of alcohol or drug use.
Effectively managing the risks and effects of drugs and alcohol so that your staff do not pose any health and safety risk at work can be especially important where there are safety-critical elements to a job role, such as driving or operating heavy lifting equipment, or using machinery, electrical equipment or ladders. Here, the misuse of drugs or alcohol could have disastrous effects for the employee, co-workers, members of the public and the environment.
Otherwise, the need for drug-testing in the workplace will depend on the specific needs of your business and whether you feel able to justify a policy of random testing. Any approach to testing should be a risk-based one that takes into account the nature of the business, where relevant factors will include whether your organisation or roles within it are safety-critical, as well as concerns over reputation, alcohol or drug-related absenteeism or poor performance.
Before obtaining information through drug or alcohol testing, you must ensure that the benefits justify any adverse impact, unless of course the testing is required by law. As a matter of good practice, you should also only use drug or alcohol testing where it provides significantly better evidence of impairment than other less intrusive means.