Asbestos surveys

What is the difference between a 'material assessment' and a 'priority assessment'?

Under regulation 4(8) of the Control of Asbestos Regulations 2012 (CAR), where asbestos is found or liable to be present in non-domestic premises, the dutyholder responsible for the premises must ensure that 'a determination of the risk from that asbestos is made'.

In other situations the Management of Health and Safety at Work Regulations 1999 require a risk assessment of significant hazards.

In January 2010 HSE released HSG 264 Asbestos: The Survey Guide. This guide expanded on and replaced MDHS 100. HSG 264 is aimed at those conducting surveys and those with specific responsibilities for managing asbestos in accordance with the regulations.

HSG 264 sets out guidance as to how to conduct these risks assessments and the factors to consider.

The material assessment considers inherent qualities of the material or component itself and thus its ability to release fibres if disturbed. The factors that will affect this are:

• the type of product (the proportion of asbestos and the extent to which the fibres are bound into component);
• its condition;
• surface treatment (if any); and
• the type of asbestos.

The priority assessment considers other factors that may affect the likelihood of the material or component containing the asbestos being disturbed and airborne fibres being inhaled. These include:

• its quantity;
• location (consideration of dilution and dispersal of fibres);
• human occupancy (type of activity, numbers of occupants or passers-by, the frequency and average length of time of exposure); and
• the maintenance regime (type and frequency).

In order to facilitate a comparison and a ranking of the risks arising from different ACMs (asbestos-containing materials), each factor is given a numerical value. The HSE publications apply a rating with a range of 0 to 3.

A separate score is derived for both the material and priority assessments by the addition of the ratings allocated for each factor.

The total risk of the ACM is calculated by adding the scores derived from the material and priority assessments.

This formula and the scoring system are not compulsory. They are merely a suggestion made by the HSE as a guide. There are more sophisticated methods that employ wider ranges and different methods of scoring and there is no compulsion to use any numerical rating system.

The purpose of the risk assessment is to determine what methods, if any, are necessary to remove or control the risk arising from each ACM.

Why do you need to separate the 'material assessment' and the 'priority assessment'?

This follows on from the previous question. The two types of assessment may be used for different purposes and be prepared by different parties.

The factors used in the 'material assessment' are collected by the asbestos surveyor during an asbestos survey. This could be in conjunction with the discovery of a single product or material suspected of containing asbestos, or as part of a wider general inspection of the premises.

Where samples are taken the results of their analysis should be incorporated and used within the assessment. Where the asbestos is presumed, the assessment should cater for the worse case scenario namely, assuming that the asbestos is blue and that any board material is asbestos insulation board rather than asbestos cement.

The material assessment is unaffected by the use of the premises and thus, subject only to its presence, condition and surface treatment, the calculated risk will not change.

It is therefore appropriate for use as an Asbestos Register or Management Plan to be referred to by others when contemplating works that might disturb the material.

The 'priority assessment' cannot be used on its own as, apart from the physical extent of asbestos, it only considers factors which are affected by the use of the premises and not the material itself. So, it is a follow on to the 'material assessment' and it is only the combination of the two that enables the total risk to be quantified.

The total risk assessment is necessary to be able to comply with the dutyholder's responsibility to manage asbestos in non-domestic premises as required by regulation 4 of CAR 2012.

It is therefore important for the dutyholder, or the dutyholder's representative, to be involved in and make, or agree, the priority assessment. It requires someone who is familiar with the day-to-day use of the premises and the maintenance regime, and is aware of the short, medium and long term proposals which may affect the assessment. Often this will not be the asbestos inspector.

In practice, the completion of the priority assessment, the review of the total risk arising and the selection of appropriate means of removing or controlling risks arising will be a collaboration between the asbestos surveyor and the dutyholder. The dutyholder, however, takes ultimate responsibility for decisions made and the implementation of the asbestos management plan.

It is important to record the decisions and ratings for the various factors in both material and priority assessments and to make this information available to the dutyholder so that, should the circumstances change for any reason, the total risk can be reassessed and methods of managing the risk revised as appropriate.