This was used to insulate industrial and domestic premises so can be found in between cavity walls, under floorboards and in loft spaces.
This is a loose, fluffy insulation material (similar to candyfloss), which may be blue-grey or whitish in colour.
Probably the most dangerous asbestos-containing material. Loose fill is made up of pure asbestos and if disturbed can release large amounts of fibres into the air, where they can be breathed in.
Do not attempt to work on this material under any circumstances unless you are a HSE-licensed contractor.