Asbestos

Asbestos was a material used in building and construction quite extensively throughout the UK between the 1950s and 1980s. Since then however, there have been major efforts to remove it due it to its carcinogenic properties and other health-damaging attributes. It was widely agreed that asbestos poses a significant health risk, though whether any types are less dangerous and whether it should always be removed remains a contentious issue.

Although large steps have been taken against asbestos, thousands of tonnes remain in many buildings. An estimated half a million commercial and industrial buildings still contain some form of asbestos.

What is asbestos?

Asbestos is a natural, fibrous mineral that was used in buildings as a good insulator, amongst other things. It is a durable material, and has good fire and chemical resistance. It exists as six different fibrous minerals; they exist naturally in soil and rocks, and the fibres can straight or curled:

  • Amosite (mineral)
  • Chrysotile (mineral)
  • Crocidolite (mineral)
  • Tremolite (fibrous)
  • Actinolite (fibrous)
  • Anthophylite (fibrous)

The asbestos fibres found in building works are very small and narrow; approximately 2000 times thinner than a human hair. This makes them very easy to breathe in and settle into the lungs. Asbestos is quite resistant to dissolving in chemicals, and as such can last a long time, maybe life time, in the lungs and can cause scarring which is asbestosis.

Where is asbestos?

In buildings, asbestos fibres can be found in a variety of building products and materials. It can be either firmly or loosely bound. Firmly bound or non-friable asbestos has been used in:

  • Fibro/AC sheeting - flat or corrugated
  • Water/flue piping
  • Roof shingles
  • Flexible building boards
  • Faux brick cladding
  • Compounds for plaster patching
  • Vinyl floor tiles
  • Textured paint
  • Linoleum floor covering backings

Loosely bound or friable asbestos may appear in older kinds of insulation that is found in heaters and stoves in domestic properties. Ceiling insulation containing asbestos is more likely to occur in commercial buildings than domestic properties.

Asbestos was also used as sprayed coating on steelwork, concrete walls and ceilings in order to insulate and protect against fire. It also existed in some partitioning, ceiling tiles and fore doors for the same reasons.

What are the potential dangers of asbestos?

Great measures are now being taken to remove potentially harmful asbestos, and in cases where this is not possible it is being sealed with a clear warning of what it contains.

If these measures are not followed, it is inevitably asbestos removal workers that face the highest risk. However, builders, maintenance workers and other contractors like electricians, plumbers and carpenters can also be at risk.

It is heavily debated as to whether certain types of asbestos are as dangerous as others, but as a general rule in the UK, all types should be avoided for safety. The relative danger and risk of inhalation depends on the length, strength and diameter of the asbestos fibres, and the risk of disease developing seems to rely upon the amount inhaled. There is no safe level of exposure, but high frequency of exposure will increase the risk.

In Great Britain alone around 3500 people die every year from mesothelioma and asbestos related lung cancer as a result of exposure. Due to our past behaviour and use of asbestos, the numbers are expected to increase.

Mesothelioma is a cancer, usually of the lung lining. It can remain latent and undetected for up to 40 years or more after asbestos exposure.

Asbestosis is the scarring of the lungs by asbestos. It results in acute chest pains and severe breathlessness, and is ultimately fatal.

Are there any regulations relating to asbestos?

  • - The Health and Safety at Work Act 1974
  • - The Asbestos (Licensing) Regulations 1983

The licensing regulations apply to jobs with a hazardous exposure like asbestos removal and stripping. It states that all employers or the self employed who work with asbestos must have, and with comply with, a licence from the Health and Safety Executive.

The three exceptions to this rule are:

  • 1. Short periods of work: for a single person it should equal a total of no more than 2 hours, or 1 hour for 7 consecutive days.
  • 2. If the HSE has been notified 28 days in advance, work by an employer with workers on their own premises is permitted.
  • 3. Work is permitted if it just for gathering samples or monitoring the air.

All work undertaken must comply with

  • - The Control of Asbestos at Work Regulations 1987, amended 1992
  • - The Control of Asbestos in the Air Regulations 1990
  • - The Asbestos (Prohibitions) Regulations 1992

The prohibitions regulations cover the prevention of the use of asbestos products in the UK and some parts of the EU. According to the HSE, asbestos slates, roof sheets, cement products and pipes must not be used in building and construction.

How is asbestos removed?

Asbestos can be safely removed from buildings, and is really the only long term solution to guarantee a safe building. Officially, sealing asbestos is the preferred route as it is quicker, less disruptive and far cheaper.

While sealing in asbestos may provide a short term solution, it will ultimately have to be dealt with if the building is altered or demolished. Disturbance or deterioration of the seal can mean that fibres will be released, and so sealing asbestos is not a complete removal of the risk. Ordinary paint or wallpaper is not a seal; a special painted coating is often applied to asbestos cement walls.

According to the HSE Guidance Notes, to safely remove asbestos insulation or coatings there are 4 possible methods:

  • 1. Dry stripping
  • 2. Controlled wet stripping
  • 3. Hot stripping with air management
  • 4. High pressure water jetting

The preferred method endorsed by the HSE is controlled wet stripping. However, dry stripping is the most frequently used. The problem with dry removal is that greater dust is produced.

In large scale removal operations where access to affected areas is difficult, high pressure water jets are implemented. This is a highly specialised and potentially dangerous process.

How can I protect myself?

Specialist equipment is required, and thus any dealing with asbestos should only be undertaken by fully equipped professionals.

Standard dust masks will not protect you against breathing fibres. A filter respirator is worn with disposable full body overalls and full head, feet and hand covering. Men should be clean shaven. Once removed, clothing should be correctly disposed of before removing the respirator and a thorough decontaminating shower should be taken.

What can be used instead?

There are several kinds of substitute for asbestos in its many applications. These can however, present their own health problems, and in some cases are an inferior substitute. There are available:

  • Different natural and manufactured mineral fibres
  • Fibrous and non-fibrous synthetic plastics
  • Natural organic fibres like cellulose

For more information, you can contact the Asbestos Information Centre or the Asbestos Removal Contractors Association.

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