Mineral Wool
It is an inorganic and non-metallic product manufactured from a carefully controlled mix of raw materials. High-temperature mineral wool is usually used in industrial furnaces and foundries as it is resistant to temperatures above 1,000 degree Celsius. Using a serrated knife is the best way to cut it by pressing it against the board so that one gets a clean clear piece of mineral wool.
It is prone to settling and compacting but otherwise last as long as 100 years. It works by trapping and holding air still. Retaining a 50mm air gap between the loft insulation and the eaves helps prevent condensation. Mineral wool Batts hold their shape which makes them easier to handle. The most common form of home insulation is the batt and roll or blanket type. It is also less expensive in comparison to other insulation materials. It is by far the best non-toxic insulation to select.