That's kapok which is another type of fluff and its safety is questionable at best. It may have the same issues as cotton fluff bedding, i.e limb entanglement, obstructions, choking.
It's used a lot in Germany and considered safe by many there, but personally I wouldn't recommend it when there are safer options, like paper and tissue.
This website has lots of information on kapok:
https://strongbrew.ca/kapok