Safety glass in windows in rented accommodation - is landlord responsible?

[bunjies]

We currently rent a house which has a kitchen extension. It is more of a sun room so has a lot of glass windows, in fact 3 sides of it is glass, but has been put at the end of the kitchen so we use it for our dining table. I would say that about 90% of the extension is glass. The lower half is fitted with that ugly bumpy stuff you sometimes see in schools with the wire grid. But the top half (more than half the total area) is plain non-safety glass. I have trawled google and have found that all glass doors must have safety glass as well as "any vulnerable point in the building" but does this apply to large windows? One of the windows has now developed a large crack which is spreading and I'm worried the whole window is going to break at some point. Does the landlord have to replace these windows?

Thanks PolterGoose.

I forgot there is also an external door made out of the same glass so am I right in assuming that would definitely need to be replaced?

Right thanks PolterGoose. So, he should replace the cracked pane with safety glass but doesn't have to replace it all?

We've got safety glass in several of our windows but you can't tell the difference between it and the non-safety glass that's in the other windows.