Working under the influence of drugs can have tragic consequences for the employee, others in the workplace, and the employer.

It is well known that things like handling, or working near, heavy machinery when under the influence has resulted in the deaths of the employee and others. Employers are liable if this occurs, have been fined significant amounts, and had to make large reparation payments as well. Could your business survive a half-million dollar pay-out?

Employers have a duty to keep employees safe as far as is reasonably practicable while at work. This includes keeping employees safe from behaviour resulting from drug use.

Employees also have a duty to keep themselves and others safe while at work, and must follow the employer’s reasonable health and safety policies and/or procedures, and reasonable instructions.

There are strict rules around when an employer can drug test an employee because drug testing can infringe on the employee’s human rights and their rights to privacy.

When will it be considered reasonable to drug test an employee?

Employees should have a clause included in their employment agreements that allows for drug testing to take place. By signing the employment agreement, the employee can be taken to have consented to the drug tests on the terms outlined in the employment agreement, and to have been given forewarning that there is a possibility that drug testing will take place while they are at work. The clause should provide that being under the influence of drugs at work may be considered serious misconduct which may result in a dismissal.  

Employers should also have health and safety policies, and/or procedures, in place that clearly set out the process that will be followed. These policies and procedures should be referred to in the employee’s employment agreement, and be brought to the employee’s attention and be made available to them. It should be provided in the employment agreement that if an employee does not follow the policies and procedures the employer might take disciplinary action against them.  

The policies and/or procedures must be reasonable. For instance, it could be considered reasonable to drug test an employee who is working in a safety-sensitive area (for example, wharf limits, energy plants, forests, cargo handling, factories, or where heavy machinery is being operated), or where the employee’s work directly impacts on the safety of other staff or the general public. It would be less likely to be justifiable to drug test an employee who is working in an office environment.

Are random drug tests allowed? In most circumstances, it will be considered reasonable for an employer to test a specific employee where the employee has shown signs that they may be under the influence of drugs, or if they have recently been involved in a workplace accident or a near-miss. However, random drug testing could also be reasonable if the circumstances mean it is necessary to prevent serious harm. If you want to do random drug testing it should be allowed for in the employment agreement.

What happens if an employee fails a drug test?

The employer’s health and safety policies and procedures should clearly set out what is to happen if the employee fails a drug test.  The employer should:

  • give a copy of the results to the employee and discuss the results with the employee;
  • consider if suspension is required (e.g. for health and safety reasons), and give the employee a chance to comment on the proposed suspension before reaching that conclusion;
  • give the employee an opportunity to comment on the test results;
  • respond to any requests for the sample to be re-tested as a fair and reasonable employer could in all of the circumstances; and
  • put to the employee the allegation that they were under the influence of drugs while at work, and that if proven, this could constitute serious misconduct which may result in the employee’s dismissal; and
  • notify the employee that a disciplinary meeting will be taking place to discuss the allegations, and that they may bring a support person or legal representative with them to that meeting.

The employer must consider the employee’s response to the allegations before making a preliminary decision as to whether the employee is guilty of misconduct. The failure of a drug test does not automatically mean that an employee was under the influence of drugs while at work, or that their performance was impaired by the drug use. It is one factor that the employer can take into account when deciding whether the employee is guilty of misconduct. Other considerations can include the employee’s response, and whether anyone was harmed.

A programme to put an employee off work (without pay) could be incorporated into the employment agreement on the basis that it is an alternative to dismissal. The employee remains off work pending clean results from further testing.

Before an employer can dismiss an employee, they must give the employee an opportunity to comment on their preliminary decision, and take into account that response before making a final decision.

It is important that the right steps are taken when testing an employee for drugs, because if an employer acts unreasonably, breaches their policies and procedures, or fails to follow fair process, then an employee could raise a personal grievance.

If you need help drafting or implementing drug policies please contact Mikayla Turner at mturner@raineycollins.co.nz or at (04) 473 6850.


Mikayla Turner
Employment Lawyer
Wellington