Check out the website for department of industrial relations in your state (I used the NSW one at my work, although it was before workchoices came in), because the booklet on the website contains information about Employer's obligations on this issue. I think you will find the situation is covered from an OH&S obligation to provide you with a safe work place. Do you have a OH&S Committee member to talk to? Otherwise call the Department of IR, Workcover or similar to see if they can provide you with information that might help you.
Whilst you don't want to jepordize your job, health has to come first.
Goodluck!