It has fibres all over the back if it. I was going to put in in the wash on its own and then run the machine through a cycle with nothing in it to clear the machine. Will this do or do I risk getting fibres on everything for ever after?
Surely there shouldn't be anything in modern insulation that's a problem?
I would do what Jaffa said and hoover it & hand it outside for a good blow around then shove it through the wash (you could always take it to the laundrette and use the commercial machine - only a couple of quid).
Thumb - it's not really a problem as such though is it?
My Aunt had hers done last year and I am up and down in her loft all the time, it is a bit scratchy etc, but really it does wash out of clothes and I've never noticed a problem next time I've worn something.
The only time I got a lot of 'transfer' was when I brought a bag down and put it on my bed, on the pillow without wiping/dusting it... that was scratchy
I guess it depends on how much is on the top - if the OP's DH was carrying the rolls of fibreglass on his back, there could be a lot. The glass particles can get into the skin and could cause infection - it's not good!