The Intelligent Quarterly from the publishers of The Insurance Insider

Summer 2018

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Under the microscope

Charles Pickles

In cases involving potential personal exposure to asbestos fibres in buildings, the need to consider "materially increasing risk" means that the detailed analysis of asbestos fibres provided by scanning electron microscopy (SEM) offers much greater levels of clarity compared to standard techniques.

Even though asbestos has been banned in construction materials since late 1999, and a huge amount removed from buildings over the years, there are still many properties of all types where the decision has been made to leave asbestos-containing materials (ACMs) in situ and manage its presence.

The decision to manage ACMs is not necessarily a bad one as asbestos in good condition can be safe as long as its presence is known about and the material is maintained.

However, for those responsible for maintaining buildings where asbestos is known to be present, the crucial question is how it can be dealt with safely?

The hazard is potentially the presence of asbestos in a building, but the risk to occupants is when the asbestos fibres become airborne and can be inhaled. An asbestos survey identifies the hazard, but on its own rarely identifies the risk present to a meaningful level.

HSE responsibilities
There are strict Health and Safety Executive responsibilities for property owners that are aimed at reducing the risks to health that asbestos poses, and there should no longer be any excuse for anyone being exposed to potentially dangerous levels of airborne asbestos fibres.

The Health and Safety at Work Act 1974 says: "It shall be the duty of every employer to ensure, so far as is reasonably practicable, the health, safety and welfare at work of all employees."

More specifically, the Control of Asbestos Regulations 2012, Regulation 4.8, (Duty to Manage) Asbestos, mandates that a determination of the risk from any asbestos known to be present is made.

Moreover, it says: "The regulation is designed to make sure anyone who carries out any work in non-domestic premises and any occupants of the premises are not exposed to asbestos from ACMs that may be present."

This responsibility falls to the duty holder, who is usually the person or organisation that has clear responsibility for the maintenance or repair of the premises. The duty holder is required to assess and manage the risks from asbestos to employees and others, and must ensure that anyone who is likely to work on, or disturb, asbestos is provided with information about its location and condition.

Government policy considers that asbestos that remains in good condition and unlikely to be damaged or disturbed is not a significant risk to health as long as it is properly managed. Only when ACMs are disturbed or damaged is the risk of exposure increased through the release of airborne fibres.

Rigorous systems of asbestos management are therefore needed to prevent staff and the public disturbing ACMs that are accessible to them. This involves the careful monitoring and management of building materials at all times.

Regular inspections and checks by the duty holder of the condition of ACMs are essential and this should include details of any precautionary or safeguarding measures that are needed. As part of this requirement an assessment of the risk associated with each identified occurrence of asbestos is required.

Effective risk management
Against a background of growing public concern over the potentially harmful effects of asbestos in buildings, modern air monitoring and analytical techniques now have the capability to detect much lower concentrations of any asbestos fibres present.

This means that the periodic monitoring of air samples is now much more relevant and realistic rather than simply monitoring conditions after building repairs or asbestos removal work.

In particular, a formal programme of reassurance air monitoring using powerful SEM can more effectively measure occupational exposure concentrations for asbestos in workplace premises than other techniques.

SEM enables asbestos in air to be quantified to very low levels, typically achieving lower limits of detection to 0.0005 fibres/cm3 and below, compared to the 0.01 fibres/cm3 capability of standard phase contrast microscopy (PCOM). SEM can also distinguish between different asbestos fibre types and other non-organic fibres.

Current analysis using standard PCOM has a limit of detection that is wholly unsuitable for risk assessment in an occupied environment and is only really valid for asbestos removal monitoring.

In such circumstances, SEM's ability to more accurately determine whether asbestos fibres are present means it can better identify the level of any risk that might be present - and what remedial actions are required.

Used in this way, air monitoring using SEM enables actual and direct asbestos risk measurements to be made in specific building locations. This in turn can be used to prioritise risk and target spending on remedial works and provide the reassurance that those present in the building are not being exposed to harmful fibre levels.

A future defence
This is particularly important in bolstering any defence against a potential future legal claim where the duty holder will need to demonstrate that the best available practicable technique was used to enable a suitable and sufficient risk assessment to be made.

In particular, the Fairchild v Glenhaven Funeral Services Ltd (2002) case specifically identifies that the appropriate test of causation is whether the employer had materially increased the risk of harm to the claimants.

With asbestos fibres there is usually a time interval of decades after any exposure before the onset of disease. For the person responsible in law for the provision of a safe working environment, the prospects of civil litigation arising at some time in the future from a very small contribution to the asbestos exposure of someone who subsequently develops mesothelioma should not be overlooked.

As a result, if potential liabilities are to be avoided or defended, it will often be necessary to demonstrate that airborne asbestos concentrations did or did not significantly exceed background levels.

To be relevant, the sampling needs to coincide with suitable and representative site activities and conditions - however, the impact of false positives associated with the inclusion in samples of non-asbestos fibres can be considerable.

In such circumstances, PCOM will give only a total fibre concentration rather than an asbestos fibre concentration, so the ability of SEM to discriminate between asbestos and non-asbestos fibres can provide a true reading.

Nobody should be complacent about the health risks associated with asbestos. Workplace air sampling and analysis utilising SEM can ratify the effectiveness of existing asbestos management techniques and prove that asbestos fibres levels are not elevated - providing vital reassurance that anyone present is not being exposed to potentially harmful asbestos fibre levels.

Charles Pickles is chief technical officer of Lucion Services.

This article was published as part of issue Winter 2017

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