I guess if a complaint was brought and you could establish to the minister that workers were being harmed, made ill because of their work, or dying because of their work, you could at least bring forward a complaint to see if you could advance that to see if there was a standard that was acceptable somewhere.
Evidence of meeting #40 for Foreign Affairs and International Development in the 40th Parliament, 2nd Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was c-300.
A recording is available from Parliament.