Established 1986 - P402 Qualified Surveyors - HSE Licensed

 47A Strand St, Sandwich, Kent CT139EU -  - 29 St Lawrence Ave Ramsgate CT110HZ

Offices: 01304 614647 / 614453 (24hr) 01843 592243 - For a Prompt Service First Call Direct - 07712068424

Email for quote or specific help: asbestossurveys-kent@yahoo.co.uk

Asbestos Surveys - Asbestos Management

"So if it's blue asbestos, why doesn't it look blue?"

All About Asbestos

Asbestos Types: There are actually more than three types of asbestos: (chrysotile, amosite, crocidolite, tremolite, anthophyllite and actinolite) but these are the three most common.

_{The 'colours' of asbestos types refer to the colour of the raw material as it comes out of the ground, fibre types are referred to by colour because its easier to remember colours than the scientific names, the fibres in products are usually mixed with other materials to such an extent that it loses its original colour in the process. You cannot tell if a material contains asbestos purely by its colour.}

 Chrysotile =  white asbestos - Serpentine (curly) Mg₃(Si₂O₅)(OH)₄

_{Chrysotile is the most commonly used asbestos fibre, you will find it in many garage roofs, house guttering and downpipes etc, these particular items are cement based and have a density greater than 500kg per cubic metre which makes them quite safe because the fibres are tightly held within the cement matrix. On the other hand, because it is a curly fibre (like wool) it can be woven and because of this aspect there are many products like rope gaskets, fire blankets, exhaust tapes, seals and even asbestos paper!, that are made from 100% pure Chrysotile. The fibre is actually quite weak and has to be either held firmly within other material or woven into flexible products. Fibre content, in a wide variety of materials that this fibre is found in, can vary from less than 1% up to 100%. Chrysotile is considered by some to be less dangerous than the other two types because a serpentine (curly) fibre is less likely to become trapped in the lungs.}

   Amosite = brown asbestos - Amphibole (straight) Fe₇Si₈O₂₂(OH)₂

_{Amosite is the next most commonly used fibre mainly in the form of AIB (Asbestos Insulation Boards), these were used usually as fire and heat protection in a wide variety of applications, domestic, commercial and industrial buildings 'benefited' from having this material as fire/heat protection. AIB was used in the same manner as plasterboard and is often mistaken for it, there has been much exposure to tradesmen etc because of this common mistake. Amosite was also used in some plastic products like toilet cisterns and seats, because of the nature of the material the fibres are trapped firmly within the resin and are quite safe. Amosite was used in thermal insulation of pipework, vessels, tanks, calorifiers, exhausts and a variety of similar products, the insulation was either applied wet in lose form or was used in pre-formed pipe insulation sections that were joined over the pipe and then wrapped to hold them together. Insulation materials can contain a high fibre content because it is a fairly soft material, any damage to this material is likely to release many fibres, which is why it is now injected prior to removal to suppress the fibres before they can become airborne.}

   Crocidolite = blue asbestos - Amphibole (straight) Na₂Fe²⁺₃Fe³⁺₂Si₈O₂₂(OH)₂

_{Crocidolite use is not as common as the other two types but considered the most dangerous because of the length and shape of the fibre (long and sharp), like Amosite it is more likely to become trapped in the lungs. It was used in a similar way to Amosite in thermal insulation and is usually mixed with the other two fibres. Crocidolite has been found in older cement type buildings (see gallery) and because in this form it is cement based is a fairly low risk but still needs treating with respect. Crocidolite was also sprayed onto surfaces to give them fire protection, structural steelwork and roofs are still being found with this coating, other surfaces and plant were also sprayed in this fashion. Sprayed asbestos coatings represent a high risk because of the very high content and the fact that the fibres are fairly lose and easily disturbed.}

Common asbestos terms:

Friability = A material's ability to release asbestos fibres based on it's condition, content and structure (density) the higher the asbestos content the softer the material is likely to be and significantly more fibres are likely to be released.

Control Measures = Control measures refer to the methods used to reduce risks, with asbestos surveying, control measures are employed to reduce fibre release to a minimum level when sampling, shadow vacuuming (with an HZ surveyors vacuum), fibre suppression sprays either PVA solution or surfactant (injection liquid) solution, sheeting of the area with PVC and tape, the use of core samplers (tubes) are also employed to reduce the risks as far as reasonably practical. If a 'surveyor' simply takes a pair of pliers and snaps off a large piece of AIB without control measures, then exposure and invisible contamination could result. Sadly this is all too common with the newer 'surveyors' who have no real experience, knowledge or appreciation of the material's lethal and long lasting sinister characteristics.

Surface Treatment = This indicates whether the friable material has been sufficiently sealed with an appropriate sealant which is strong enough to prevent the material shedding fibres during normal use of the area. The sealant should be strong, flexible, resistant to heat, damp and water, the main product we use in the encapsulation industry is called ET150 which is a thick rubbery emulsion type coating which is usually painted or sprayed onto the surfaces.

Control Limits = The control limits, the limit of asbestos exposure when working with the material, it is the limit which must not be exceeded either by the nature of the material (low friability) or the strict control measures employed to suppress and reduce airborne dust levels. Any fibre measurements above the control limits (as a result of air sampling) means that you must wear a mask (P3 rated), the mask alone will only protect you for short term and low level exposure. Used in the asbestos industry control limits apply to both fibre types (serpentine and amphibole) and are expressed as 'less than x fibres per millilitre of air' (f/ml). The limit for Chrysotile is <0.03 f/ml for 4 hour exposure and <0.09 f/ml for short duration exposure( 10 minutes), the control limits for Amphibole asbestos (brown and blue) is <0.02 f/ml for four hours and <0.06 f/ml for short term exposure (10 minutes). Any exposure above these limits, you are required to wear a mask, (masks are worn regardless of limits) to give you some idea of an AIB fibre release and control limit fibre exposure comparison, breaking AIB sheets will release more than 10 fibres per millilitre of air. >10 f/ml (10,000 fibres per litre of air!). source HSE publications. I hope you can now see why the regulations are so strict and why an accurate survey and good asbestos management is important, especially when dealing with these friable materials.

Material Assessment = The material assessment is dealt with in detail on the Envacs page, basically it is an assessment of the risk from a particular material based on various parameters as detailed in MDHS100 "Surveying, Sampling and Assessment of Asbestos-Containing Materials"  which should be included in the asbestos survey to enable accurate asbestos management.

The following information is repeated in these pages because of its importance in surveys

   The information that should have been included in your survey is:           

Asbestos type, likely content, material type, material use, surface treatment (sealed), general condition (damage), material amount, material location, occupation level of area, occupation frequency of area, occupation duration of area, size of area, likely disturbance through normal use of area, likely disturbance through maintenance of item/plant/area, photos, drawings, register, analysis certificates (from independent UKAS labs only, not 'in-house') all these are given a score and used to calculate the risk and priority (priority of remediation not removal) of the material.

Upgrading / re inspecting to this level of information should seriously be considered.

AIB = Asbestos Insulation Board mainly used as fire protection, typically containing 30-40% Amosite (brown) and Chrysotile (white) asbestos HIGH FRIABILITY when disturbed, significant exposure will result from damaging this material. Very often mistaken for lower risk cement sheeting or plasterboard (similar properties) and has been (unsafely) removed by unscrupulous builders and tradesmen on many occasions, beware!.

Asbestos Cement = Cement based material with a density greater than 500kg per cubic metre LOW FRIABILITY usually a hard brittle material with low to medium asbestos content, low risk if treated with common sense. Mainly found in domestic properties on garage roofs and walls, guttering, downpipes, loft water tanks, facia panels, etc. Should be ignored unless broken or removed.

Asbestos Rope, Paper and Tape = Made from pure woven Chrysotile and is 100% asbestos HIGH FRIABILITY, usually found as gaskets, gap sealants, heat safety protection and exhaust insulation, underlay paper back for flooring materials, requires careful removal after soaking/dampening.

Composite Materials = Plastics or resins containing firmly held asbestos fibres, floor tiles, cisterns, sink pads, bitumen products etc LOW FRIABILITY, usually low content and low risk, the fibres are firmly trapped within the main plastic/resin material.

Asbestos Insulation = Various amounts of asbestos content and can contain any combination of asbestos types HIGH FRIABILITY, medium to high content and requires injection with liquid surfactant prior to removal, removal must be by licensed contractors only!

_{Health Effects From Asbestos}

The health effects of asbestos exposure are well documented, apart from various cancers, Mesothemiola etc exposure can cause other health effects such a Pleural Plaques and similar chest conditions. Most are incurable and a prolonged painful death usually results. Even a short duration exposure can result in serious health problems, this is why the regulations are so strict, this is why it needs to be treated with respect and to be dealt with in a responsible manner by experienced, licensed and competent companies.

It can take between 10 and 4 years to develop asbestos related health problems, its not like a cut or a burn where the pain lets you know what has happened, with asbestos exposure you unknowingly breath in virtually invisible fibres that remain trapped in your lungs for a long time before causing health problems at a later date.

There is a link to the mesothemiola website in the links page.

asbestos surveys kent - asbestos surveyors kent