Well, there are a few different things you can do. If there is a Shop Steward or Health and Safety Rep who works on your site, you should let them know first. If not, then there are still lots of ways you can work this out. If you're a union member and there's nobody in your workplace that you feel comfortable reporting it to, you can submit an alert form <here> to our OHS department who will endeavour to get in touch with you and help you with the issue.
Worksafe are the Government regulator of OHS in Victoria, so you should definitely let them know that something isn't right. Too often companies get to tell us that "there were no issues before now" when something goes wrong, just because nobody had reported them to Worksafe - So it pays to be diligent. You can also alert the local council area that you're working within to the problem.