An employer cannot require an employee to undertake a breathalyser test without a clear policy framework in place. Where testing is conducted on the basis of reasonable cause, that reasonable cause must fall within the parameters defined in the employer's policy. Such testing is more likely to be considered justified in safety-sensitive work environments.
Suspension pending investigation may be an appropriate interim measure, particularly where the employee's role involves safety-sensitive duties.
Following a positive test result, the employer must conduct a thorough investigation before taking any disciplinary action. The key consideration is the "likelihood of impairment" rather than merely the fact of a positive result. Employers can only act upon what is known . A positive breathalyser test does not automatically establish impairment or provide sufficient grounds for dismissal without further investigation.