whats the actual problem with the composite residues?
When I did my training in respect to dealing with the aftermath of accidents the hazard was after impact the structure could break up into microscopic particles which could enter the body by inhalation or through unprotected skin. The respirators required to work safely were very high spec as was the suit.
Once in the body, they could not be removed as they were so small and numerous.
The other danger was any wind could contaminate large areas downwind.
I admit when I was trained I was very sceptical but the trainers were pretty convincing about the hazards.