BURNT out cement houses that are riddled with asbestos can be an occupational health and safety danger zone.
Getex Director Jason North says that when an asbestos cement building burns light flakes of asbestos containing material (ACM) can settle on surrounding areas.
These flakes do not burn - they are small and light – and rise up in the air. They can be easily transported with the wind.
Flakes of ACM can cover land, foliage and buildings in an asbestos flake 'snow', according to Mr North.
Mr North has seen these flakes lodge in cobwebs in bushes, in swimming pools, and in all sorts of places where they can be difficult to remove.
“If not attended to quickly, people or pets may walk across the 'snow', then carry the asbestos inside the house,” he said. “A quick response is vital.”
Asbestos in this form is classified as friable*, therefore an asbestos removal contractor with an AS1 licence is required to clean up the material.
The removal must be conducted in association with the NATA accredited asbestos in air monitoring** method.
Mr North said that in the days following a building fire that has released and spread ACM it is unlikely airborne fibre levels would exceed any relevant Australian guideline for countable fibres, which conform to defined geometric criteria.
“Considerations for those within the vicinity must include the obvious observation that any dust which becomes airborne has the potential to contain respirable fibres,” said Mr North.
“The situation must be monitored in order to assist in the risk assessment/decision making process.”
The spread of asbestos materials from one property to another brings with it many other issues besides occupational health and safety and site contamination.
An experienced consultant can advise those involved in the clean up works, assist in the management of the removal, provide air monitoring and issue the final site clearance following the removal of all accessible asbestos contamination and get the building/home owner back on track to re-building.
Once the asbestos has been taken care of, normal building works can then resume.
"The Code requires that the risk be assessed and action taken,” said Mr North. “The most significant danger is that the asbestos is inhaled.”
There is a hierarchy of control measures that should be undertaken, including ensuring people do not become exposed to the flakes.
“This can be achieved either by excluding people from the area and removing the source of contamination, which is the most favourable option, or by requiring people to wear personal protective equipment, which is the least favourable option,” said Mr North.
“Until effective hazard control measures can be put in place, preferably rapid clean up action, NATA air monitoring for airborne asbestos is a requirement for the development of an appropriate risk control strategy.”
This air monitoring can be undertaken by Getex who can also provide associated services such as the development of asbestos sampling plans, asbestos removal control plans or scope of work reports, soil classification and disposal reports and asbestos clearance inspections and reports. Getex is NATA accredited for asbestos fibre monitoring and air volume measurement.
Getex has experienced qualified staff with many years of project experience working alongside council, project managers, insurance companies and building controllers/owners, including the management of small and large scale asbestos clean up works following house/building and bush fires. Getex can be contacted 24 hrs/seven days a week.
* WorkCover NSW defines friable asbestos material as any material that contains asbestos and is in the form of a powder or can be crumbled, pulverised or reduced to powder by hand pressure when dry.
Sprayed limpet, millboard, pipe and boiler lagging are examples of friable asbestos.
Asbestos inappropriately buried (ie not in accordance to any environmental legislative requirements) is considered friable asbestos material.
Any asbestos cement product, which has been subjected to weathering, severely damaged by hail, damaged by heat/fire or other mechanical action, or illegal water blasting is a friable asbestos product and an AS1 licence for friable asbestos is required for its removal.
** The NOHSC: 3003 (2005) Guidance Note on the Membrane Filter Method for Estimating Airborne Asbestos Fibres, second edition, describes the method of determining possible respirable fibres as: "A sample is collected by drawing as measured quantity of air through a membrane filter by means of a sampling pump. The filter is later transformed from an opaque membrane into a transparent, optically homogeneous specimen. The respirable fibres are then sized and counted in accordance with defined geometric criteria, using a phase contrast microscope and calibrated eyepiece graticule. The result is expressed as fibres per millilitre of air, calculated from the number of fibres observed on a known area of the filter and the volume of air sampled”.