Asbestos is a silicate mineral that occurs naturally in the environment. It appears as tiny fibres that, on their own, are not visible to the naked eye. It is these fibres that can make you sick if they are inhaled.
Asbestos fibres were added to many building materials because they helped to strengthen them, as well as provide other benefits including improved insulation and heat-resistant properties.
The trick when it comes to remaining safe and healthy in the presence of asbestos is knowing which building materials these fibres were added to, and taking the appropriate care when coming into contact with them.