What is asbestos personal air monitoring and testing? (And when would I need it?)

Asbestos personal air monitoring and testing – a process normally referred to as “personal sampling” – is a form of asbestos air testing that is carried out on individual persons. The aim of this type of asbestos air monitoring is to monitor the personal air the given individual is breathing in during an activity where asbestos may be involved. This, in turn, can help ensure the adequacy of certain control measures.

Personal sampling plays a crucial role in ensuring asbestos safety, in addition to being a legal requirement in certain circumstances. Regulation 19 of the Control of Asbestos Regulations 2012 (CAR 2012) states that it must be carried out on employees, unless asbestos exposure is not liable to exceed the control limit.

In this article, we will explain more about what asbestos personal air monitoring is, its significance as an important safety measure, and the circumstances in which you would require it.

What is asbestos personal air monitoring and testing?

Whether one knows it as “asbestos personal air monitoring”, or simply “personal sampling”, it is a type of asbestos air testing that is designed to test the air the testing equipment wearer is likely to be breathing in.

Personal sampling is not the only form of asbestos air monitoring; others include the likes of asbestos background testing and asbestos leakage testing. However, asbestos personal air testing differs from these in its focus on the air being breathed in by a particular individual.

The basics of how it works are as follows: the individual wears the personal air monitoring equipment, with a filter being mounted close to their breathing zone. This allows for the collection and sampling of the air that the wearer is likely to be breathing in. The results can then be reviewed to check whether the given individual has come into contact with respirable asbestos fibre.

Asbestos personal air testing therefore plays an imperative role in assessing a given individual’s exposure to asbestos fibres during normal work activities in which the dangerous substance may be involved. Non-asbestos workers can also benefit from such testing, if they are in a property or area where there is a strong likelihood of them coming across asbestos-containing materials (ACMs).

When is asbestos personal air monitoring and testing necessary?

Regulation 19 of CAR 2012, on air monitoring, sets out that “every employer must monitor the exposure to asbestos of any employees employed by that employer by measurement of asbestos fibres present in the air.” This must be done, the regulations say, “at regular intervals”, and “when a change occurs which may affect that exposure”.

In practice, as an employer, you should be arranging for personal sampling in the below scenarios, as part of your efforts to give your workers the best possible protection:

• Before the commencement of any work that may disturb ACMs
• During asbestos removal or remediation projects
• As part of ongoing asbestos management in buildings known to contain asbestos.

What are the benefits of asbestos personal air monitoring and testing?

Arranging for asbestos personal air monitoring to be carried out on your workers will bring you the following benefits:

• It will enable you to check your employees’ exposure to asbestos fibres in the air
• It will allow you to confirm the adequacy of the control measures you have put in place, as well as the respiratory protective equipment (RPE) your workers are using. This will help give you confidence that the RPE you have chosen provides your employees with an appropriate degree of protection
• It establishes employee exposure records. These records will need to be retained for 40 years, and they must be available upon request, in case an employee needs to refer to them
• It supports current and future risk assessments.

As a responsible employer, you will be doubtless anxious to take the actions necessary to help protect your workers from the risk of breathing in or ingesting asbestos fibres.

Personal sampling will therefore play a fundamentally important part in your implementation of effective asbestos management and control measures – and as a result, your compliance with both CAR 2012 and broader health and safety legislation in the UK.

How to conduct asbestos personal air monitoring and testing

A detailed rundown of the steps involved in asbestos personal air monitoring can be found in Appendix 1 of the Health and Safety Executive (HSE)’s publication under the HSG248 series code, Asbestos: The Analysts’ Guide.

Nonetheless, the essentials of the personal sampling process can be described as follows:

The selection of the right equipment

Asbestos personal air testing entails the use of a sampling pump to draw a measured volume of air through a membrane filter, with this serving as the “sample”.

In order to comply with the World Health Organization (WHO) standard method, the sampling equipment will need to take the form of an open-faced filter holder. This should be fitted with an electrically conducting cylindrical cowl and exposing a circular area of filter with a diameter of at least 20mm. The cowl should normally extend 1.5 times to 3.0 times the effective filter diameter in front of the filter.

A personal sampling head typically comprises a base plug, a base that allows for uniform dynamic pressure across the filter face, back-up pads, and a filter. It must also have a cowl made from electrically conductive material. The remaining components are the end cap and the end cap plug, with the end cap needing to be removed for sampling.

The measurement of the airflow

A working flow meter will need to be used to measure the airflow; this will need to have been calibrated against a primary standard.

Presuming that normal operating conditions apply, it will not be necessary to measure the temperature and pressure, as doing so would only have a small impact on the total uncertainty. This means that in the UK, there isn’t any need to make corrections to sample volume due to changes in atmospheric temperature and pressure.

The preparation for sampling

When personal sampling is being carried out, the filter holder should point downwards, and be fixed to a part of the worker’s clothing that is as close as practicable to the mouth and nose – preferably within 200mm. Potential locations for the filter holder to be fixed include the given individual’s upper lapel, hood, or shoulder.

Where there may be localised concentrations, it is advisable to position the sampling head on the side that is expected to give the higher result. If the person subject to asbestos personal air monitoring is wearing a respirator, it is important to position the sample head away from the clean exhaust air.

It is also crucial for each filter holder to be uniquely identified. This should include a record of the person whose nearby air is being sampled, as well as the date and other relevant site information (for example, the type of activity that is being carried out, and any environmental factors that may impact on the results).

The sampling process

When it is time for the sampling itself to be carried out, any protective cap will need to be removed from the filter holder, and the pump will need to be switched on to warm up, to achieve a stable flow rate. The flow rate should be set to the flow required, using the working flow meter.

During the actual sampling period, if a filter cassette shows signs of damage, or of being overloaded with particulates, it will be necessary for this to be exchanged. When the sampling period comes to an end, the working flow meter should be used to remeasure the flow rate, prior to the pump being stopped.

Finally, it will be possible to review the results of the asbestos personal air testing process. This will involve the filter being examined under a microscope, and the number of respirable fibres being manually counted. All observed fibres will be measured, to determine which fibres are respirable. Following a complete count of the fibres’ correct size, the concentration of fibres in the sampled air will be calculated.

Conclusion: personal sampling is crucial for protecting human health

The importance of asbestos personal air monitoring and testing should not be doubted, especially for those working in environments where asbestos is present.

Both employers and property owners across the UK have obligations to monitor and manage asbestos in a responsible manner, in order to comply with health and safety law and keep workers safe. Personal sampling can play a central role in this.

To learn more about our own professional asbestos services here at Oracle Solutions, and to request a free quote for asbestos air testing or related solutions, please don’t hesitate to call us today, or to send us an email.