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Material Assessment Score

Asbestos Knowledge Base

The duty to manage under CAR 2012 requires a written plan to be produced, specifying the measures to be taken to control and manage the risk from identified and presumed ACMs. That is to say Management Surveys must do this, Demolition Surveys do not require the assessment.

Objective of Assessment

The assessment is primarily to determine the potential for the release of fibres for each of the survey items found.

Factors Required

There are 4 parameters;

  1. product type
  2. extent of damage or deterioration
  3. surface treatment
  4. asbestos type

The Asbestos ToolKit™ allows users to calculate the factors required from a simple to use screen so that the material assessment score can be calculated and recorded as part of the survey as required by HSE.

The Algorithm

The Material Assessment Algorithm is calculated by adding the 4 'scores' from the 4 parameters in factors required above. The total is known as the Material Assessment Score. The total is further interpreted to give a potential to release fibres as follows;

  • 10 or above; Have a high potential to release fibres
  • 7-9; Medium potential
  • 5-6; Low potential
  • 4 or below; Very Low potential

The Asbestos ToolKit™ automatically calculates these results from survey data entered into the database.

Product Type (or debris from product)

As defined by the HSE's Material Assessment Algorithm;

  • Score 1 - Low risk
    Asbestos-reinforced composites (plastics, resins, mastics, roofing felts, vinyl floor tiles, semi-rigid paints or decorative finishes, asbestos cement etc).
  • Score 2 - Medium Risk
    Asbestos insulating board, mill boards, other low density insulation boards, asbestos textiles, gaskets, ropes and woven textiles, asbestos paper and felt
  • Score 3 - High Risk
    Thermal insulation (eg pipe and boiler lagging), sprayed asbestos, loose asbestos, asbestos mattresses and packing

Extent of Damage or Deterioration

As defined by the HSE's Material Assessment Algorithm;

  • Score 0 - No risk
    Good condition: no visible damage.
  • Score 1 - Low Risk
    Low damage: a few scratches or surface marks; broken edges on boards, tiles etc.
  • Score 2 - Medium Risk
    Medium damage: significant breakage of materials or several small areas where material has been damaged revealing loose asbestos fibres.
  • Score 3 - High Risk
    High damage or delamination of materials, sprays and thermal insulation. Visible asbestos debris.

Surface Treatment

As defined by the HSE's Material Assessment Algorithm;

  • Score 0 - No risk
    Composite materials containing asbestos: reinforced plastics, resins, vinyl tiles.
  • Score 1 - Low Risk
    Enclosed sprays and lagging, AIB (with exposed face painted or encapsulated), asbestos cement sheets etc.
  • Score 2 - Medium Risk
    Unsealed AIB, or encapsulated lagging and sprays.
  • Score 3 - High Risk
    Unsealed lagging and sprays

Asbestos Type

As defined by the HSE's Material Assessment Algorithm;

  • Score 1 - Low risk
  • Score 2 - Medium Risk
    Amphibole asbestos excluding Crocidolite.
  • Score 3 - High Risk

Important Note

HSE advise that presumed or strongly presumed asbestos containing materials are scored as Crocidolite (3) unless analysis of similar samples from the same building shows a different asbestos type, or there is a reasoned argument that another type of asbestos was almost always used.

If in doubt, Score 3!

The material assessment score is the sum of the 4 parts above.