Asbestos Insulation – A Guide to Asbestos Used in Insulation

Does Insulation Contain Asbestos?

If your building was built (or has been refurbished) before the year 2000, then there is a possibility that any insulation within the building may contain asbestos. Asbestos was frequently used in a variety of construction materials throughout the century until it was banned in the UK in 1999. There are a number of countries worldwide that still use asbestos. It has highly effective fire-resistance and insulating properties, it was cheap, durable and readily available and was, therefore, used extensively during the 20th century (especially the 1960s and 70s) in the production of insulation.

What Does Asbestos Insulation Look Like?

Insulation that contains asbestos may not be readily obvious to the untrained eye. There are in fact 6 different types of asbestos: chrysotile, crocidolite, amosite, tremolite, actinolite and anthophyllite. Each type has a unique appearance when viewed through a microscope however asbestos types appear very similar to the naked eye. Insulation can take many forms, as explained further below.

What Colour is Asbestos Insulation?

The colour of insulation does not necessarily correlate with the types of asbestos fibres that are present within it. The colour will most likely be dictated by the material used, such as calcium silicate or magnesium carbonate – colours commonly vary from grey, to tan, to salmon pink, but this is not an exhaustive list. The insulation itself may also be wrapped or coated with a different material.

Asbestos insulation will contain at least one of the regulated asbestos fibre types. Chrysotile, crocidolite and amosite were the 3 most commonly used types of asbestos in the UK construction industry.

• Chrysotile – also known as white asbestos, these fibres tend to be curved and flexible.
• Crocidolite – usually blue or grey, these fibres are thin, brittle and needle like in appearance.
• Amosite – brown asbestos that, like crocidolite, are normally comprised of needle like fibres.

Tremolite, actinolite and anthophyllite were much rarer and were not used commercially. However, they can sometimes be found as contaminants in other types of asbestos and other materials derived from a mining process.

• Tremolite – can appear as white, green, grey and a range of other light colours.
• Actinolite – these fibres are generally of a dark colour.
• Anthophyllite – tending to be of a dull green, grey or brown colour.

Find out more about the appearance of asbestos here.

Asbestos Insulation Dangers

Asbestos only presents a threat to your health when its fibres have been released into the air. Once they are airborne they can then be inhaled through your mouth and nose and easily become trapped within your respiratory system.

Some of the risks associated with asbestos exposure include:

• Mesothelioma – an aggressive form of cancer that develops in the thin layer of tissue covering some of your organs.
• Asbestosis – a serious long-term lung condition that causes shortness of breath.
• Lung cancer.

It’s worth noting that these health problems may not become apparent until later on in life – different asbestos-related diseases have varying latency periods, often being diagnosed 20 years or longer after the initial exposure.

Different Types of Asbestos Insulation

Thermal insulation that contains asbestos can be grouped into 4 main categories:

Asbestos Block Insulation

Block insulation refers to the method of adhering or fixing a slab of insulation block to a surface. Although this is quite a simple method of insulating buildings or plant, the problem is that in the past these blocks contained a large of asbestos (between 6-85% by volume) which presents a major exposure hazard if the blocks become damaged or disturbed in any way.

Where you might find asbestos block insulation: Walls, floors and ceilings, and to plant or equipment.

Loose-Fill Asbestos Insulation

Loose-fill insulation is one of the most dangerous forms of insulation. Designed to be either blown or poured into hollow areas and roof voids it is extremely fibrous and will readily release fibres into the air. This material frequently consists of 100% pure asbestos fibre.

Where you might find loose-fill asbestos insulation: Wall cavities, attic floors and other areas of buildings that are not readily accessible.

Sprayed Asbestos Coating

Sprayed insulation was frequently used to protect steelwork and other structures from fire, provide corrosion resistance, or acoustic insulation. As the name suggests, the material was mixed with small amounts of binding agents and sprayed onto surfaces. This process in itself was extremely hazardous causing millions of asbestos fibres to become airborne. The sprayed coatings contained a high percentage of asbestos that could be easily damaged and disturbed after application.

Where you might find sprayed asbestos coatings: Ceilings, walls, structural steelwork and irregularly shaped structures that would be difficult to insulate with more conventional insulation. We also find debris and overspray residues to surrounding surfaces and crevices, including beneath floor coverings, left over from the original spraying operation.

Pre-formed and Loose applied Asbestos Insulation 

Old insulation coverings used on plumbing and heating/ventilation plant can contain high percentages of asbestos (up to 85% by volume). This type of insulation can deteriorate with age and, as a result, potentially  release large quantities of asbestos fibres.

These may take the form of rigid sectional insulation, which was moulded in a factory and delivered to site then clasped onto pipework, or hand-applied hard set lagging which was a dry powdered mix delivered to site then mixed with water to form a plaster-like consistency – this was applied to pipework and left to cure to become rigid.

Where you might find asbestos insulation : Pipes, ducts and other plumbing/HVAC plant. We often find residues of insulation to surfaces adjacent lagged or previously-insulated pipework, remnants of the original insulating operation.

How to Remove Asbestos Insulation

Asbestos insulation can only be removed by contractors that have been licensed by the Health and Safety Executive to do so. These contractors employ highly trained and competent operatives that understand the hazards associated with asbestos removal. They have specialist equipment and decontamination facilities that ensure the work is undertaken safely and the asbestos waste is disposed of correctly.

Incorrect removal of asbestos can result in high levels of exposure to individuals undertaking the work and any personnel in the area or who may subsequently occupy the area.

A specialist asbestos removal company must be employed to undertake this type of work.

Asbestos Insulation Testing

If you would like to conclusively determine whether insulation in a building contains asbestos please don’t hesitate to get in touch with our team today. Here at Casa Environmental Services we provide UKAS-accredited asbestos surveying and analytical services to clients throughout the UK.

We will take a sample of the suspect material and analyse it in our specialist laboratory . If asbestos is present we can advise on safe management or removal as appropriate,. We can also assist in the compilation of a management plan to ensure compliance with The Control of Asbestos Regulations 2012 Regulation 4 (Duty to Manage)

See more: Mesothelioma and Asbestos – An Overview of Mesothelioma

See more: Asbestos Testing – The Ultimate Guide to Asbestos Testing