Most loft insulation materials, with the exception of Purlite/Vermiculite, Rockwool, and Isocyanurates, are not especially safe in a fire. These materials are generally a lot more expensive than alternatives such as EPS ( expanded polystyrene) Styrofoams( extruded polystyrene) and Glassfibre. However the cheaper ones will burn readily with the former two giving off very toxic fumes. However as most ceilings are at least half hour fire resistant it should allow time to evacuate. If you are still in a raging house fire after half an hour then I think it is good night Vienna anyway and you are past caring if your loft is a fire hazard. Bubblewrap and cardboard would still not be advisable as they would provide fuel any possible fire. Given that most people have all sorts of materials in their lofts that would provide fuel for a fire anyway it may be an academic point. One point about EPS, the white stuff available in sheets from builders merchants and the protection around your new television, sterio etc. Do not let electric cable rest on it or go through it. It causes the plasticiser in the PVC cable to migrate into the EPS and the insulation will harden and fall off, likely causing a short circuit or even a fire.

On the issue to hand I agree with the suggestion that a charity shop may welcome such a material for wrapping. Iy does also make good insulation protection for non hardy plants to over winter, either outside or in a greenhouse or potting shed. My friend has layers of it stapled to his shed walls to insulate form the cold.

Cheers Concrete