A qualification credential does not replace or remove an employer's responsibility for an employee's health and safety. The employer is responsible, regardless of the certification process, as described in the Workers Compensation Act (Part 3, Division 3).
It is the employer’s responsibility to affirm that the employee has met the competency standards as part of the certification application process.
You may, as the employer, assign the responsibility to someone else in your employ. In doing this you continue to carry the responsibility as stated above - your responsibility cannot be transferred in any way.