One of the great fallacies that is current is that this or that is a legally required. Some things are prescribed by law, but that is relatively little. Most OHS is not a legal requirement, but rather someone's attempt to put in place a safe system of work to meet the general requirement of the law that employers take reasonable care for the safety of their employees. It often seeks to prevent well beyond what would be needed for a safe system of work.
In this regard, speaking as a lawyer, a lot of what passes a OHS "requirement" is not something that the courts support. For example, a lot of people think that there have to be signs all over the place warning of the dangers of everything. In fact, our High Court has said quite consistently over the last 5 - 10 years that you don't need to warn against the obvious danger (eg a clear edge of a high cliff which is fenced off) or against the random - as one judge said, if you put a sign up along the road specifying every thing that could happen, the greatest risk would be running into a sign!
I admit that this is a bit of a revision of the position that some courts were taking in the 1960s, 70s, 80s and 90s which seemed to work on the basis that the person with the deep pocket has to take 100% responsibility for all injury. However, too many people have taken too much of a read from some of the more extreme views expressed then and have not noticed that the courts now are saying that in assessing what is a risk that needs to be guarded against, a person is entitled to assume that others will use at least a reasonable degree of caution to look after themselves (at least if they are adults).