Paint

[Bob906]

I bought a 5L tin of White Vinyl Emulsion (bought too much not needed) about 4 years ago it has remained unopened in the Kitchen loft ever since Will it be any good to use now.

[heathfield]

The paint itself should be perfectly OK, though you'll have to make sure you've stirred it very thoroughly (!)
The problem might be the container, If there's any rust on the inside rim of the container, and this falls into the paint, it's almost impossible to get rid of, and you'd very likely end up with rust spots on the painted wall or ceiling.
I wouldn't open it just to have a look, as this seems to encourage the formation of rust. Keep it unopened until you think you want to use it.