Asbestos Materials

Asbestos has been in use for thousands of years but was used extensively in the UK from the 50's up until it was eventually banned in the 90's. It is a naturally occurring mineral that was popular because of its strengthening and resistance properties. Initially it was used as an insulation product because of its resistance to high temperature but was also used as a binding agent in plastics and cements. As a result a surprising number of products and materials contained asbestos fibres.

Asbestos is dangerous because when the fibres are inhaled they lodge in the linings of the lungs causing disease and cancers (see Asbestos Illness). A single fibre can cause cancer but, as with smoking, the more you expose yourself the higher the likelihood of developing a problem. So, if an ACM cannot release fibres it is of no risk. The most important factor when calculating risk, therefore, is the likelihood of fibre release following disturbance - known as friability. The low-risk materials are considered so because they are normally of a composite nature and do not shed fibres in large numbers even when badly damaged. The high-risk materials however are very friable and will often fill a room with airborne fibres when disturbed.

Different asbestos fibres also pose different levels of risk. There are six asbestos types three of which are commonly found in the UK (some products contain more than one asbestos type). The most dangerous group - Amphibole asbestos - includes Crocidolite, or blue asbestos, Amosite, or brown asbestos, and the less common Anthophyllite, Tremolite and Actinolite. The use of all Amphibole asbestos was banned in 1985 and all are most commonly found in thermal insulation products. The least dangerous is group is called Serpentine asbestos and is formed only of Chrysotile, or white asbestos, which was commonly used as a binding agent and was used in almost all material types until it too was banned in 1999.

We can see then that the highest risk materals are those that are highly friable, especially if they contain Amphibole asbestos.

• Building materials (asbestos cement sheets, drainpipes, gutters, roof tiles, and roofing felt )
• Thermal insulation (asbestos insulation board [AIB], sprayed coating  and lagging)
• Fireproofing (mill board, asbestos paper, asbestos rope and asbestos flashguards)
• Plastics (asbestos floor tiles, toilet cisterns, sink pad)
• Friction products (gasket,  brake pads)
• Adhesives and sealants (putty, resins, tile adhesives, mastic)
• Decorative (paint, textured coating [artex], wallpaper)

Building materials

Cement

Asbestos fibres were combined with cement to form a very strong and resilient building material known as asbestos cement. It usually contains the lower risk Chrysotile (white) asbestos fibres but it is worth performing an asbestos test to determine whether the higher risk Amosite (brown) or Crocidolite (blue) asbestos fibres are present.

Due to the strength of the product it is difficult to release any dangerous fibres unless badly damaged so its generally regarded as a low risk material and can be removed by non-licensed contractors. If you intend to remove this material yourself we recommend that you protect yourself by wearing disposable P3 masks.

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ROOFING SHEETS
Perhaps the best known asbestos containing material; asbestos cement roofing sheeting is can commonly be seen on shed and warehouse roofs in every town in the UK. The presence of asbestos is often indicated by mosses which grow on this natural occurring material.

PIPES&GUTTERING
Asbestos cement rainwater goods including guttering and drainage pipes were used extensively up until the 90's. Asbestos cement is resistant to most acids and alkalis making it perfect for transporting rain water from your bathroom to your drain. Other uses include water tanks, conduits, window boxes and sewer pipes.

It is also commonly used as flue-piping because of its thermal resistance.

BOARDING
Cement board is commonly found in properties built in the 50's and 60's when it was used as panelling in studded partitions, ceilings, soffits and baths.

ROOF TILES
Asbestos roof tiles (shingles) are common on British rooves. Because asbestos is a naturally occurring mineral you will often see moss growing on these tiles as opposed to non-asbestos rooves where only a few tiles will be moss-covered.

As with all suspect materials the only way to be sure is to perform an asbestos test.

Roof Felt

Asbestos roof felt was used between 1910 and 1995 and typically contains 10-15% Chrysotile (white) asbestos fibres mixed with asphalt. It is a composite material and therefore there is little risk of fibre release unless badly damaged.

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Thermal Insulation

Products used for thermal insulation (rather than protection) generally pose the biggest risk. This is because they tend to contain high percentages of asbestos which are normally Amosite (brown) or Crocidolite (blue) that are generally considered to be more dangerous than Chrysotile (white).

Contractors require an HSE licence to remove or work upon any of these products. These works will always be carried out in controlled conditions typically involving respiratory protective equpment, purpose-built enclosures and decontamination procedures.

ASBESTOS INSULATION BOARD
Asbestos Insulation Board, or AIB, is perhaps the most common of the insulation products still around because many of the others have been removed. It was typically used to line or clad areas around a heat source such as a boiler or hotwater pipe.

It is very similar to plaster board in consistency and was commonly used between 1930 and 1985 when it was banned (along with all other insulation products). AIB normally contains upto 30% of Amosite and/or Crocidolite making it very dangerous when exposed or damaged.

It is more extensively used as a fireproofing material particularly in ceilings (often as a tile) and dividing walls and was even used as a building material in studded partitions, soffits and cladding. In fact anywhere you might use plaster board you will find AIB.

SPRAYED COATING
Asbestos sprayed coating was a cement sprayed directly onto surfaces to form a hard protective layer for the purpose of fireproofing, insulation, sound proffing and even decoration. Over time this material becomes increasingly unstable and will crumble with very little pressure applied and is therefore considered to be extremely hazardous especially as it can have concentrations of upto 90% asbestos.

It is very difficult to work with this material without significant fibre release so you should always consult an HSE licensed contractor before commencing remedial works.

LAGGING (PIPE WRAP)
As with sprayed asbestos, asbestos lagging has very high concentrations of Amosite and/or Crocidolite and is very friable. Often, though, it will be covered in a protective layer of sealant or meshing that prevents fibre release. If this layer is not damaged then it is perfectly safe to leave it in-situ as long as you monitor it.

It difficult to remove because it tends to stick to the pipe and you will occasionally see evidence of previous 'bad strips' in boiler rooms where debris can be found around the pipes and on the floor. This poses a greater hazard than the original material and it is often far easier and cheaper to get a specialist to seal or encapsulate the product with specialised asbestos sealants.

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Fireproofing

Asbestos was commonly used for fireproofing from the mid-twenties through to the eighties. As well as fireproofing materials such as millboard it was also used to create asbestos rope or cord and formed into products such as ironing board covers, fire blankets, oven gloves and mats.

MILL BOARD/PAPER
Asbestos mill board (similar to cardboard) and paper was used as a fire protective lining to ovens, heaters, plant, PVC tiles, damp course, pipe insulation, cladding and inside metal fire-doors where it acts as a fireproof soundproofing agent. It was also used in bank and library vaults as a fireproof lining to storage boxes.

TEXTILE PRODUCTS
Because of its fibrous nature asbestos (especially Chrysotile) can be woven to form a textile that was knitted to create fireproof products such as fire blankets and ironing board covers. It was used formed into rope or cord and used as a seal on ovens & windows or coiled around handles on kitchenware such as kettles and pots to prevent burnt fingers.

Other uses include cable-wrap, aprons, curtains, matresses and packing.

FLASHGUARDS
A very common use of asbestos cement is as a flashguard. These are linings to electrical goods that protect the object from sparks and electrical current. These are very common in electrical switchgear, fuseboxes, fuses and transformers. As with all cement products the risk of fibre release is low unless the product is damaged.

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Plastics

A plastic material is generally a polymer combined with a fibrous binding agent that produces a material that is malleable either at high temperatures or at room temperature. As we already know asbestos was often used as a binding agent in cements and this also applies to plastics. These materials are all of a composite nature and form the lowest risk of all asbestos containing materials because polymers do not generally decompose and thus the asbestos fibres remain protected for many years. 

ASBESTOS FLOOR TILES
From 1950 to 1980 Chrysotile asbestos fibres were used as a binding agent in the production of polyvinyl plastics often used as floor tiles and stair nosings.  These products are not considered to be high risk but care should still be taken when removing them especially if the adhesive is also found to contain asbestos. Specialist floor tile scrapers are available.

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TOILET CISTERNS
The old dark brown or black solid plastic toilet cisterns invariably contain Amosite (brown asbestos) or Chrysotile (white asbestos) fibres. As long as the cistern is kept intact the risk of fibre release is very low and this product can safely be removed and disposed of at a designated asbestos waste site.

SINK PADS
Sink pads were used under metal sinks to reduce the noise produced by running water. They are very common and many contain Chrysotile (white asbestos) fibres that were used to bind the bitumen soundproofing agent. They form a very low risk because there is little likelihood of fibre release while the product is in-situ. It is often easier to encapsulate or seal a damaged sink pad rather than remove it. This should be done using specialist asbestos encapsulants.

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Friction Products

Asbestos is a very durable mineral, is heat resistant and does not breakdown easily and is therefore well-suited to use as a friction product such as brake linings and gaskets.

BRAKE LININGS
Up until 1980 nearly all brake linings were formed of asbestos but as a result of asbestos bans in Scandanavia manufacturers looked for less hazardous alternatives. Today asbestos friction products are only normally found in old motors like those in lifts.

Normally formed of Chrysotile, asbestos brake linings will almost always be badly damaged and liable to fibre-release and there is also likely to be airborne asbestos fibres as a result of previous abrasion. In enclosed spaces such as lift motor rooms we would recommend that an air test is performed to check the levels of airborne asbestos fibres. Should these prove to be high then you should contact a specialist to recommend a suitable course of action.

GASKET
Because of it natural resistance to heat, abrasion, electricity and chemicals, asbestos was the perfect product for use in gaskets. Asbestos gaskets are normally formed of high concentrations of Chrysotile (white) and are considered low risk when in good condition.

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Adhesives and sealants

RESINS, MASTICS, PUTTY & TILE ADHESIVES
Chrysotile (white) asbestos was commonly used as a binding agent in resins, mastic, putty and flooring adhesives from the 1940s up until the 1980s. These are the lowest risk category of asbestos containing material because there is little likelihood of fibre release. Care should be taken though not to sand or scrape these products.

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Decorative

PAINT & TEXTURED COATING (ARTEX)
Chrysotile (white) asbestos was used in low densities in textured coating (also known as artex) and some decorative paints up until the end of the 1970s. These products are safe as long as they are in good condition and there is little risk of fibre-release unless scraped, drilled or sanded. If  for prolonged periods (> 1 hour) unless carried out under controlled conditions by a licensed contractor. You should always protect yourself by wearing a P3 mask and dampening the area before you commence any works.

If you wish to perform any of these actions and know or you suspect that your material pre-dates 1980 then we'd recommend that you have a sample analysed first. On the 13th November 2006 the Control of Asbestos Regulations 2006 took this material off of the list of 'high-risk' materials that need to be removed by licensed contractors. This was a controversial decision as many asbestos experts believe this to be a hazardous material.

DIY products are now available that allow you to skim or plaster over textured coatings an this is a safer alternative to removal.

WALLPAPER
Vinyl wallpaper that pre-dates 1980 may well contain small quantities of Chrysotile (white) asbestos. This is little risk of fibre-release from such products is unlikely unless damaged and you should avoid scraping without wearing a P3 mask.

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