The HSE outlines 7 steps to consider taking if your company discovers an employee is under the influence of substances [2]:

  1. Understand your legal duties to protect your employee
  2. Chat with your employee to understand their perspective
  3. Assess your safety-critical workers and decide if your need an accident investigation
  4. Evaluate your drugs policy to ensure it’s understood and watertight
  5. Give support through education, resources and counselling options
  6. Decide if your employee will face disciplinary action
  7. Review your policy in terms of the current UK law.