Asbestos is a term used to refer to six naturally occurring silicate minerals.
It is mined from the Ground and found in seams within the rock.
The image to the right shows asbestos fibres still in a piece of rock. The fibres are the fluffy grey looking material.
There are three main types of Asbestos; Blue or Crocidolite, Brown or Amosite and then White or Chrysotile.
Asbestos has some fantastic properties; All are fire resistant, inert to chemicals, Blue and Brown are acid resistant and White is resistant to alkalies, absorbs sound energy, doesn’t conduct heat energy, electrically non conductive, strong, and flexible.
Blue and Brown asbestos have long straight fibres like needles, and White fibres and soft, silky and flexible. Each type has its own properties but these are the main ones which meant it was used within building materials starting in the 1800s.
Where was Asbestos used?
The intention of this section is not to show you everywhere asbestos was used. Mainly because it was used in so many places, but to highlight some of the main uses.
Because of it’s excellent properties asbestos was used in approximately 3500 products within the UK, and approximately 6 Million tonnes of raw asbestos was imported.
Initially asbestos was used as an insulating material, loose like rockwool, or around pipes and hot water tanks. The early use was of the White (Chrysotile) Asbestos, but later Brown and Blue Asbestos were imported and used in vast quantities in many different products.
Some of the most common uses were in Asbestos insulating boards (AIB), Asbestos sprayed coatings, sometimes called limpet or flock, Asbestos based textiles, Asbestos cement, decorative finishes such as Artex, and plastics, most commonly floor tiles and the adhesives.
Asbestos insulating board was used in vast quantities throughout the UK, most commonly as a fireproofing material but also:
- partition walls
- fireproofing panels in fire doors
- lift shaft linings
- ceiling tiles
- panels below windows
Asbestos sprayed coatings were applied onto building structures; exposed steel beams, concrete and even brick walls. Unfortunately the Asbestos is not always visible if hidden within a buildings structure. Sprayed coatings can be upto 85% Asbestos with a mix of adhesives, and can be very fragile releasing millions of fibres into the air when disturbed. The images below show sprayed coating on a beam and then two ceilings in a school. You can see the fibres hanging down.
Why is Asbestos hazardous?
One thing that most people will know is that Asbestos is dangerous, but not why? So why is it?
As we said at the start, Asbestos has many great properties, chemical resistance, fireproof, acid resistant and strong. Unfortunately it is these properties which make it so hazardous.
Asbestos is found in fibres in the ground which are too large to be useful, so were processed to make a useable product. This involved, breaking up the rocks, crushing the fibres and filtering to get fibres of a specified size.
Asbestos will keep breaking down into smaller and smaller size fibres until they are of a respirable size, eg can enter the lungs.
Once in the lungs the sharp fibres will embed into the lung tissue where your bodies natural defenses attack the fibres but fail due to the resilience of the material, and actually cause scarring of the lungs.
Asbestos is also a Group 1 Carcinogen, it is known to cause Cancer and Mesothelioma, a Cancer of the lining of the lungs.