What is a fibre count?

During clearance or background monitoring the Air pumps draw a known quantity of air over a known period of time onto a membrane or SEM filter. The filter traps fibres, which are prepared (in our accredited Gracefield lab) and counted under a phase contrast microscope. The volume of air and fibre count are used to determine a concentration - fibres/mil. This concentration assist with determining whether an area is safe ocupy or clear of airborne fibres above an exposure limit. 

When a fibre count is high, an additional count and identification can be carried out to determine whether the fibres are asbestos (Serpentine - Chrysotile, or Amphibole - Amosite & Crocidolite). The concentration can be recalculated for asbestos fibres only. Read more... Please get in contact with us at the Laboratory to discusss the PLM Fibre Count option. 

What is Clearance Monitoring? 

When an asbestos removal specialist carries out any asbestos removal at a house, commercial or industrial premise, they should be carrying it out in accordance with legislation and codes of practices which aim to protect the public and ensure the site is free from asbestos after the removal is complete. Clearance monitoring is asbestos air monitoring carried out at the removal site after the job has been completed and the removal specialist has cleaned the area. In many cases it is a four stage process involving inspection and testing even before the removal has started. 

What about Background and Reassurance Monitoring?

Background monitoring and Leak monitoring can also be carried out during and throughout the removal process. Leak air monitoring occurs outside the 'enclosed removal area' to determine whether the area is secure and that no asbestos fibres are escaping during the removal process. Background montitoring occurs in the vicinity of the removal works site.

Reassurance monitoring (sometimes called Background monitoring) occurs in buildings and locations where asbestos is present but there has been no removal works carried out and the area or workplace remains occupied. Air monitoring in such areas can help to reassure occupants of the air quality.