Asbestos

Asbestos is the generic term for naturally occurring silicate minerals which contain thin fibrous crystals. Each visible fibre is composed of millions of microscopic “fibrils” that can be released by abrasion and other processes (such as manufacturing) into Asbestos Containing Materials (ACMs).

Asbestos has desirable physical properties, including sound absorption, average tensile strength, and resistance to fire, heat, and electricity, and is relatively inexpensive. 

It has been used in such applications as electrical insulation for hotplate wiring and in building insulation. When asbestos is used for its resistance to fire or heat, the fibres are often mixed with cement or woven into fabric or mats. 

Prolonged inhalation of asbestos fibres can cause serious and fatal illnesses including lung cancer, mesothelioma, and asbestosis. Illness from asbestos exposure can be found in records dating back to Roman times. 

Asbestos respirable fibres in ACMS are generally defined as a particle of length greater than 5 microns, a diameter less than 3 microns and an aspect ratio of at least 3:1. These are obviously very small, cannot be seen as individual fibres, and can easily be inhaled.

Asbestos is a fibrous form of hydrated (and usually impure) magnesium silicate. Of the five or so variants that occur, only three have important industrial uses. 

1. CHRYSOTILE: commonly known as “white” asbestos. 
2. CROCIDOLITE: commonly known as “blue” asbestos. 
3. AMOSITE (GRUNERITE): commonly known as “brown” asbestos. 

There are a number of other forms of asbestos such as actinolite, tremolite and anthophyllite to which the Control of Asbestos at Work Regulations apply. 

Of the various types of asbestos, chrysotile is known as a serpentine fibre, whilst the remainder are referred to as amphibole fibres. 

NOTE: Colour must not be relied upon for positive identification 

Asbestos is a naturally occurring mineral that is extracted from the ground. Asbestos has been mined in most parts of the world, including Europe, but most mines are now closed. However, asbestos is still mined in other areas of the world, predominantly in Russia, Kazakhstan, China, India, Zimbabwe and Brazil. 

Asbestos-containing materials (ACMs) are manufactured in many parts of the world but has been banned within the United Kingdom (UK) and the European Union (EU). 

In this country the use of Crocidolite (blue asbestos) was subject to a voluntary ban in 1970 and Crocidolite and Amosite (brown asbestos) was prohibited for supply in 1985] and for the manufacture of new materials in 1992.

The ban was extended to include most Chrysotile (white asbestos) containing materials’ manufacture, supply and installation in November 1999. However, asbestos is still to be found in many old buildings and plant. It is difficult to define precisely what “old” means in this context, certainly installations completed before 1999 might be suspect, but there can be no guarantee that asbestos will not be found in more recent applications. 

The current legislation is the Control of Asbestos Regulations 2012, which came into force on 6 April 2012. In the list of the regulations, only those that are in bold are relevant to Home Adaptations, as only specialist personnel should perform this type of work. If asbestos containing materials are suspected as being present in the work are and could be damaged by the work a competent Asbestos Surveyor should be engaged to confirm the presence of asbestos and a Licenced Asbestos Removal Contractor should be engaged to perform the asbestos work. 

Regulation 4 Duty to manage asbestos in non-domestic premises 

This regulation covers the duty to manage asbestos in non-domestic premises. 

It requires duty holders to identify the location and condition of asbestos in non-domestic premises and to manage the risk to prevent harm to anyone who works on the building or to building occupants. It also explains what is required of people who have to co-operate with the main duty holder to enable them to comply with the regulation. 

Non-domestic premises include the common parts of domestic premises. 

Regulation 5 Identification of the presence of asbestos 

This regulation requires “employers” to identify the presence of asbestos and its type and condition before any building, maintenance, demolition, or other work, liable to disturb asbestos, begins. This means that a HIA must ensure that the identification of the presence of asbestos is included as part of an adaptation project. 

It also sets out the requirement to arrange a survey if existing information on the presence of asbestos in the premises is incomplete or appears unreliable. 

Regulation 6 Assessment of work which exposes employees to asbestos 

This regulation requires a HIA (employer) to carry out a risk assessment to identify the risks of asbestos exposure. It sets out the requirement to record any significant findings and put in place steps to prevent, or reduce, exposure to employees. 

Regulation 10 Information, instruction and training 

This regulation requires HIAs (employers) to make sure that anyone liable for disturbing asbestos during their work, or who supervises such employees/operatives, receives the correct level of information, instruction and training to enable them to carry out their work safely and competently and without risk to themselves or others. 

L143 – the Approved Code of Practice for managing and working with asbestos, contains the following requirements for training: 

Asbestos awareness training should be given to employees whose work could foreseeably disturb the fabric of a building and expose them to asbestos or who supervise or influence the work. 

It should be given to those workers in the refurbishment, maintenance, and allied trades where it is foreseeable that ACMs may become exposed during their work. This includes architects, building surveyors and other such professionals – such as adaptations surveyors. 

This requirement does not apply where the HIA (employer) can demonstrate that work will only be carried out in or on premises free of ACMs. This information should be available because of the assessment made by the duty holder under the duty to manage in regulation 4 and the duty on the employer agency to identify the presence of asbestos in regulation 5. 

Asbestos awareness training should cover the following topics: 

• the properties of asbestos and its effects on health, including the increased risk of lung cancer for asbestos workers who smoke
• the types, uses and occurrence of asbestos and ACMs in buildings and plant
• the general procedures to be followed to deal with an emergency, e.g. an uncontrolled release of asbestos dust into the workplace
• how to avoid the risks from asbestos, e.g. for building work, no employee should carry out work which disturbs the fabric of a building unless the employer has confirmed that ACMs are not present. 

Asbestos awareness will not prepare employees or self-employed contractors:

• to carry out work with ACMs. Awareness training is only intended to help 
• to avoid carrying out work that will disturb asbestos or ACMs. 

If work is planned that will disturb ACMs, further information, instruction and training appropriate to the work being done will be needed. 

Home Improvement Agency personnel who supervise or influence building work are required to have Asbestos Awareness Training. 

Other asbestos training is required for employees whose work will knowingly disturb ACMs, including task-specific training in addition to the asbestos awareness training. 

Refer to paragraphs 225–275 of L143 for further details of training, information, instructions, refresher training and certificates required. 

The control limit is the maximum concentration of airborne asbestos fibre to which any person who works with asbestos may be exposed. This level must not be regarded as a target figure and if it is reasonably practicable to reduce exposure to levels below the control limit then this should be achieved. 

The control limits for asbestos are measured in fibres per cubic centimetre of air (f/cm3). A fibre is defined as a particle of length greater than 5 microns, diameter less than 3 microns and a length to breadth ratio of at least 3:1. Fibres of this particular size are not visible to the naked eye, which will detect diameters of approximately 50 microns – these particles have a diameter less than one tenth of that which can be seen. 

• The control limit for all types of asbestos is 0.1 fibres/cm3 of air averaged over a continuous 4-hour period 
• The Approved Code of Practice has a specified a ‘maximum peak value’ for all types of asbestos of 0.6 f/cm3 over 10 minutes which must not be exceeded if the work is to be described as being ‘sporadic and of low intensity’, so allowing the work to be performed without notification and by persons who do not hold a license to work with asbestos. 
• Where asbestos work has been performed the work area must be confirmed as being adequately cleaned by the issue of a ‘Clearance Certificate’, which would confirm the area clean by air sampling. Note that air sampling will not be required for asbestos work areas out of doors or for non-licensed work, although the ‘Clearance Certificate’ will still be required. The air sampling must confirm that the asbestos within the air is less than 0.01 f/cm3. 

When it is anticipated that the action level is likely to be exceeded then a number of measures such as notification to the enforcing authority, medical surveillance etc. are invoked. 

Asbestos is a source of danger only if it penetrates the body tissues and although it can be ingested, the usual route is by inhalation. This is most likely to happen when it is suspended in air as respirable dust. In the second half of the 1920s it became apparent that asbestos could cause a specific fibrosis (or scarring) of the lungs called ASBESTOSIS. About 20 years later it was confirmed that asbestosis could be complicated by the development of LUNG CANCER. Still more recently a relationship has been demonstrated between asbestos and the occurrence of MESOTHELIOMA.

It is estimated that, within the UK, there are over 5,000 asbestos-related disease deaths per year. The following adverse health effects are caused by asbestos exposure: 

Mesothelioma 

Asbestos is the most common cause of mesothelioma. Up to nine out of ten cases of mesothelioma (90%) are caused by exposure to asbestos fibres. Mesothelioma doesn’t usually develop until many years after exposure to asbestos. It can take any time from 10–60 years, although the average is about 30–40 years after exposure. 

Pleural mesothelioma 

When asbestos is disturbed or damaged, it releases tiny fibres that can be breathed into the lungs. Asbestos fibres are very fine and can make their way into the smallest airways of the lungs. Once the fibres are in the lungs, the body’s defence mechanisms try to break them down and remove them. This leads to inflammation in the lung tissue. The asbestos fibres can also travel through the lung tissue to settle in the outer lining of the lung (the pleura). Over many years they can cause mesothelioma or other lung diseases to develop. 

Peritoneal mesothelioma 

Asbestos fibres can also be swallowed, and some of the fibres can stick in the digestive system. They can then move into the outer lining of the abdomen (the peritoneum). Here, they cause swelling and thickening of the lining and can lead to peritoneal mesothelioma. 

Lung cancer 

Lung cancer caused by the inhalation of asbestos fibre most commonly occurs in the bronchi, i.e. the tubes passing from the windpipe towards the roots of the lungs. Amongst people who have been exposed to asbestos the incidence of lung cancer is very much greater in those who smoke. It is considered likely that the risk of lung cancer amongst persons who have been exposed to asbestos and who stop smoking will be significantly reduced. 

Asbestosis of the lung 

Asbestos fibres in the lung cause fibrosis or scarring of the delicate lung tissue. Breathing becomes more difficult and painful as the lung tissue becomes progressively harder and more useless and less oxygen is absorbed. Symptoms may include shortness of breath, coughing, wheezing, tiredness and “clubbing” of the fingers and toes. Strain on the heart can lead to death from heart failure. 

Laryngeal cancer 

Cancer of the larynx is another risk associated with exposure to asbestos, although there is a greater chance that it may be cured and deaths are rare. 

Pleural Plaques  

Benign thickened areas which do not become malignant or impair lung function. (Pleura is the lining of the chest inside which the organs are contained). 

Diffuse Pleural Thickening 

This can sometimes cause signs of lung impairment and may be associated with asbestosis, but often not found except on X-ray.  

Asbestos Warts 

These are caused when fibres are caught under the skin and form callous-like growths, which are benign. 

The most useful properties of asbestos are incombustibility, its resistance to heat, acid and many other forms of chemical attack, good electrical insulation, good binding agent due to its long fibres, and its resistance to weathering. Blended with cement and similar materials it was widely used as a building material such as roof sheets and pipes, and in combination with calcium silicate and magnesia it forms a thermal insulation material for boilers, steam pipes and similar applications. Asbestos-based compounds have in the past been applied by spray techniques to provide fire-resistance. Spun and woven into cloths or tapes, it forms the basis of filter-cloths, vehicle brake linings, fire curtains, electrical insulation and many other items of everyday industrial and domestic equipment.

If you are not qualified to work with asbestos, you should not deliberately disturb any asbestos containing materials (ACMs). A general builder should be informed of any identified ACMs within their work area, and any necessary protection required to prevent damage to the ACMs. 

Due to Home Improvement Agencies performing work within domestic properties it is the agency’s responsibility to provide this information or ensure that the builder arranges an asbestos survey before any work commences. The resulting report should contain information on all the samples that have been taken and analysed, plus assumed asbestos containing materials. This will include drawings of the building showing where asbestos has been found and any un-accessed areas, as below. 

If you suspect that a material that you are about to disturb may contain asbestos, do not continue work, but inform your supervisor/manager of your suspicions. 

It is not legally required for ACMs to be marked as such, but signage does reduce the likelihood of inadvertent disturbance. If you see a symbol, as shown, do not work on that material. 

In an emergency

1. STOP WORK IMMEDIATELY
2. Prevent anyone from entering the area & remove any personnel from the affected area to an area away from others, preferably outside. Barrier off with warning signs if possible.
3. All employees in the affected area should be checked for any signs of dust or debris on themselves or clothing.
4. If necessary, and if practicable, remove clothing & place in plastic bag. Put on a pair of disposable overalls if available, alternatively wipe down any contaminated clothing with wet wipes or a damp rag.
5. Notify Employer or Client.
6. Client or Employer to contact specialist for advice.
7. Wait outside property for further advice. Be conscious of your movements, i.e. do not sit in a vehicle, stay away from others until advice is sought.
8. Bulk samples from release/fall and swab samples from clothes to be taken for identification by a competent person.
9. Dependent on results, Client/Employer to arrange for clean-up. If confirmed as asbestos record the incident on personnel file.

In an asbestos emergency, the most important task is to ensure that the asbestos spreads as little as possible, without endangering the personnel dealing with the emergency.