Friable and non friable
Asbestos occurs in both bonded and unbonded forms.
Bonded asbestos is where asbestos is mixed with other materials, such as cement. In this form, it is non friable – less likely to break into pieces.
Unbonded asbestos is where the raw mineral is used as lagging or insulation – in this form it is friable and easily gives off dust.
Even bonded asbestos can release fibres when it is weathered or degraded.
On the right is a picture of of bonded unfriable asbestos shed.