Nyiregyhazi wrote:What specific data says it doesn't let mineral fibres through?
What specific data says it does?
What specific data says mineral wool spontaneously creates micro-particles?
I think it's fair to scrutinise whether this is more than a feeling....
Yes, it is... but you haven't shown any evidence, so it remains an unproven theory based upon your own concerns and little more.
I think we should at least recognise uncertainty....
Sure. And I think you've done that.