What is Asbestos?
Asbestos is the name given to a group of naturally occurring minerals that are made up of long, thin, crystalline fibres. Asbestos is found within other rocks in thin veins between 1 mm and 5 mm thick. The rock containing asbestos is normally dug from open cast quarries outside the UK and is processed to release the asbestos fibres.
There are six types of asbestos:
- Chrysotile (white asbestos)
- Amosite (brown asbestos)
- Crocidolite (blue asbestos)
Where is it found in buildings?
Asbestos was used extensively in the UK from the 1940s to the 1980s for a range of uses:
- Sprayed asbestos and loose asbestos packing were generally used as fire breaks in ceiling voids.
- Moulded or pre-formed coatings and lagging were generally used in the thermal insulation of pipes and boilers.
- Sprayed asbestos and asbestos in a cement matrix were generally used as fire protection in ducts, firebreaks, panels, partitions, soffit boards, ceiling panels and around structural steel work.
- Sprayed asbestos and board materials were often used for sound deadening in walls and ceilings, usually as a coating or as tiles.
- Asbestos cement products include corrugated roofing sheets, corrugated sheets for wall cladding, gutters, rainwater pipes and water tanks.
- Millboard, paper and paper products containing asbestos were used for the insulation of electrical equipment, and as sandwich or backing materials, for example on wood veneers or linoleum.
- Asbestos ropes and products woven from asbestos fibres such as cloths.
- Certain textured coating, decorative plasters and paints, for example 'Artex' type finishes and cornices.
Why is Asbestos a problem?
Once free from a matrix such as concrete, and if allowed to become airborne, asbestos fibres can split down, reducing in size until they are small enough to travel deep into the body where they are trapped in the innermost sections of the lungs. These fibres are at least five microns long and less than three microns wide - for comparison, a human hair is sixty microns in diameter. Therefore one micron of asbestos fibres is the equivalent of one human hair split sixty times along its diameter. The body does not have a mechanism for removing materials of this size from this deep within the lungs.
When the asbestos fibres are embedded in the lungs and their linings, they will remain in the body for the rest of that person's life and can cause several debilitating and fatal diseases including lung cancer, mesothelioma and asbestosis. The greater a person's exposure to unbonded airborne asbestos, the higher the number of fibres that could be present in the lungs, and the greater the likelihood of disease. Asbestos kills more people than any other single work related cause.
Asbestos and the Environment
Asbestos is classed as a carcinogen (cancer causing material). Materials containing it, or likely to be contaminated with it, must be disposed of as Special Waste / Hazardous Waste.
Asbestos-contaminated soil has probably resulted from mixing soil with demolition rubble, poor housekeeping at industrial sites or poor waste disposal practices in the past.
Any materials containing asbestos that could become airborne should, where possible, be kept damp.
Any material containing asbestos should be deposited in covered locked skips and should be double bagged. The material must be clearly labelled. Contractors who specialise in removing asbestos will use red, thick plastic sacks with asbestos warnings printed on the outside for disposing of asbestos contaminated materials.
Disposal of Asbestos
Never dispose of asbestos in a dustbin or an ordinary skip.
Essex County Council offer a domestic collection and disposal service, it must be from your own property and you must arrange it yourself. Sheets must be individually double wrapped in plastic and bags of broken pieces must weigh more than 20kgs. No civic amenity sites are are licensed to take asbestos so disposal must be through Essex County Council or an approved removal contractor (visit the HSE website for a list of licence holders). For disposal via Essex County Council please see below for details:
Up to 40 kilos
Will be collected free of charge. Call Essex County Council Waste and Recycling Helpline on 0345 603 7625. They will arrange for their contractors to collect it.
Over 40 kilos
Same as above but there is a charge of approximately £10 per sheet.
Over 200 kilos
There is a surcharge payable and it may be worth obtaining a quote from another contractor. The Environment Agency can provide a list of approved removal contractors and they can be contacted on 08708 506 506.
The most common types of asbestos to be disposed of are:
- Sheets, i.e. concrete from garage roofs.
- Guttering 40kg is usually 10m of guttering.
- Water tanks, one tank is usually 40kg.