Friable asbestos products are generally quite loose and, when dry, can be crumbled into fine material or dust with light pressure, such as crushing with your hand. These products usually contain high levels of asbestos (up to 100% in some cases), which is loosely held in the product so that the asbestos fibres are easily released into the air.
If disturbed, friable asbestos products are dangerous because the asbestos fibres can get into the air very easily, and may be inhaled by people living or working in the area.
However, when non-friable asbestos products are damaged or badly weathered (including hail damage) they may become friable.
Non-friable (bonded) asbestos products are made from a bonding compound (such as cement) mixed with a small proportion (usually less than 15%) of asbestos. Bonded asbestos products are solid, rigid and non-friable, and cannot be crumbled, pulverised or reduced to powder by hand pressure. The asbestos fibres are tightly bound in the product and are not normally released into the air.
Common names for bonded asbestos products are 'fibro', 'asbestos cement' and 'AC sheeting'.
When they're in good condition, bonded asbestos products do not normally release any asbestos fibres into the air. They are considered a very low risk for people who are in contact with them, as long as appropriate safety precautions are used when they are disturbed.
However, when bonded asbestos products are damaged or badly weathered (including hail damage), areas may become friable.