Health and Safety at Work Act 2015, s 83
You can refuse to do work if you believe it would expose you (or anyone else) to a serious risk. The risk has to come from an “immediate or imminent” exposure to a hazard.
You then have to raise the problem with your employer as soon as you can. You could do this with your company’s health and safety representative. If the problem isn’t resolved you can continue to refuse to do the work, so long as you have reasonable grounds for believing there’s a serious risk.
You can contact Worksafe (0800 030 040) anonymously if you’re concerned about any unsafe or unhealthy work situation that could lead to death or serious injury or illness. You could also contact your union.
Note: You’ll have reasonable grounds for continuing to refuse to do the work if you’ve been told by your workplace’s health and safety representative that it would expose you or someone else to a serious risk.
If your employer fires you or disadvantages you in some other way for stopping work on health and safety grounds, you may be able to take a personal grievance against them to the Employment Relations Authority (see the chapter, “Resolving employment problems”). You can’t be treated unfairly because you’re involved in health and safety.