There are quite stringent rules for making an Octopus for a preemie, the type of yarn being one of them.
They have an approved list of yarns but my Rowan cottons aren't on there so I have done a test wash at 60C but am unable to test in a drier as I don't have one!
I have used:-
Rowan Cotton Glace - Orange - 100% Cotton
Rowan Handknit Cotton - Pink - 100% Cotton and
Sirdar Pure Cotton Double Knik - Black - 100% Cotton as a control as this is on the approved list.
I also tested my Coats Polyester Filling.
So I stuffed them in a sock and popped in a 60C wash.
All the yarns were slightly longer when wet (above) but returned to original length after drying (left)
Hoping they get approved as I have quite a supply from my Mother as she used to have a wool shop and has quite a store of yarns left over still.