So why test for Drugs and Alcohol? Testing is an integral part to any Drugs and Alcohol Policy. Without testing, there is no “tool” to prove or disprove whether a person is “under the influence” (as defined by the Policy).
Smelling alcohol on a person’s breath is not sufficient. Drug and Alcohol awareness training will help, but you also have to measure the level to make a refined and empowered decision. This information, if calculated and collected in a legally defensible manner, can be used to support any further actions that may be required. This process is sometimes referred to as “Chain of Custody”.
Testing alone cannot prove “impairment”. Impairment can be considered as subjective.

When should you test for Drugs and Alcohol?

Generally, the types of testing carried out by the majority of companies within the UK fall into the following categories:

  • Pre-Employment
  • Pre-Appointment
  • Random and un-announced
  • For-Cause / With Cause
  • Employee / Person compliance

Why test for drugs and alcohol as part of the selection or recruitment process? Testing helps ensure you are not importing further risk into your business. Potential employees are often given prior notice to such testing. However many are likely to be unaware how long certain drugs (particularly cannabis) can remain in the system and therefore produce a positive result. Even when employees are informed well in advance of their pre-employment assessment that a drug screen is included, positive rates may be reasonably high.


Where a current employee is moving job roles (often promotion) why test for drugs and alcohol? Drug and alcohol testing helps to ensure that they are taking responsibilities (as required by their employer) seriously – leading by example.

Random / Unannounced

Why test for drugs and alcohol randomly and un-announced? Random drug and alcohol testing aims to reinforce the drugs and alcohol policy in order to ensure continued compliance. It discourages continued use/abuse of substances that will affect work performance and therefore should reduce:

  • accidents/incidents
  • absenteeism
  • poor productivity levels
  • theft & corruption
  • etc…

Random and un-announced testing is a proven deterrent for employees to fully abstain from drugs or alcohol abuse long term, rather than just abstaining to pass a pre-employment test. A percentage of the workforce should potentially be tested each year, recommended at approximately 5-10%.

For-Cause / With Cause

For-Cause drug and alcohol testing should ensure immediate testing of employees who present themselves for work appearing to be under the influence of drugs or alcohol.
With-cause drug and alcohol testing is where there are reasonable grounds to suspect those employees’ actions or omissions have contributed to an accident or incident.
Testing should ideally be carried out as soon as possible from identifying any potential risk or issue. Why test for drugs and alcohol at this time?

  • Root cause analysis
  • Prevent accidents and incidents
  • Reduce false claims of compensation
  • Help promote a culture of health and safety
  • Spot issues in the workforce that can be treated

Recognising the signs and symptoms and how/when to call for a “For-Cause” test are key elements to management / supervisor education and training.

Employee / Person compliance

Why Employee / Person compliance test for drugs and alcohol? Well, this final category of testing really applies to employees or persons who are:

  • engaged on an Employee Assistance Program or
  • where proof of “fit for task” must be proven BEFORE undertaking a task
  • to demonstrate abstinence

Where treatment and rehabilitation has taken place, it is necessary to ensure compliance (abstinence) when returning back to normal duties. These tests may carry on for a period of twelve months or more, and is proven to help the employee to remain in compliance to the policy.
It has been proven that by using all of these methods as part of a robust Drugs and Alcohol policy, it will (amongst many benefits) reduce the risk of harm to our employees either through their own actions or from the actions of others.
Carrying out only single categories of testing alone will lead to less successful policy maintenance and less consistency throughout the company.