Asbestos as a Health Risks

Asbestos Health Risks

All forms of asbestos fibres are carcinogenic, the risk being dependent on the type of asbestos, the propensity of the ACM for fibre release, and the likelihood of exposure to such fibres. An ACM which is in good condition, sealed, and with a low likelihood of disturbance poses a very low-risk of causing asbestos-related disease.

The most common diseases related to asbestos exposure are:

• Mesothelioma – a cancer of the mesothelium, the fluid-filled membrane which lines the lungs (pleura), the intestines (peritoneum) and the heart (pericardium). Mesothelioma is now the most common asbestos-related disease with over 2200 people (as of 2008) developing the disease in the UK each year. Because of the long average latency period (the length of time between exposure and first onset of symptoms) of around 38 years, the annual death rate from mesothelioma is still increasing and is not expected to reach a peak for another four or five years (i.e. around 2015 to 2016). The disease is nearly always caused by exposure to asbestos, principally the amphibole types such as crocidolite and amosite.
• Lung cancer – cancerous tumours occurring inside the lungs, proven or considered most likely to have been caused by exposure to asbestos fibres. Unlike mesothelioma, where the disease is principally related to amphibole asbestos exposure, chrysotile asbestos (a serpentine fibre) is also strongly implicated in the onset of lung cancer. Because there are multiple other potential causes of lung cancer, principally from smoking and/or exposure to industrial or environmental pollutants, the death rate from this disease attributable to exposure to asbestos is difficult to determine with certainty. About 15 years ago, the HSE used to assume a comparative death rate twice that of mesothelioma (as evidenced by the increased incidence of lung cancer among asbestos workers) but it is now probably lower than a ratio of 1:1 because of the increasing death rate from mesothelioma, and the shorter latency period associated with lung cancer. About 2000 people per year are currently estimated to be dying of asbestos-related lung cancer in the UK.
• Asbestosis – progressive scarring of the lung tissue caused by asbestos exposure. Asbestosis has the best dose-response relationship of all the asbestos diseases, with a strong correlation between the amount of exposure to asbestos and the likelihood of disease occurrence. Asbestosis is actually pulmonary fibrosis triggered by exposure to asbestos fibres (as opposed to the same disease triggered by exposure to α-quartz, cristobalite or tridymite, i.e. silicosis). Asbestosis has a comparatively short latency period of 10 to 15 years. As a consequence the death rate attributable to asbestosis is now at a comparatively low level of around 120 people per annum.
• Other diseases – these include pleural plaques, considered benign and, apart from in Scotland) no longer warranting compensation, asbestos warts (a localised effect, now rare, usually attributable to prolonged handling of asbestos insulation materials) and cancers of the throat, larynx, stomach and bowel, although these are very rare.

Alexander Nicoll CCP (Asb.), AFOH

Senior Consultant, Asbestos Consultants to the Environment Ltd

Legal requirements for Asbestos Management

Legal Issues

The importation supply and use of products containing crocidolite and amosite asbestos was banned in 1985, although in reality most products containing such materials had been voluntarily phased out much earlier; in the case of crocidolite since the early 1970s and for amosite mostly by the beginning of the 1980s. These Prohibition Regulations also banned the use of all types of asbestos insulation and sprayed coatings. Thus chrysotile asbestos, where used in such products, was also banned.

The 1992 Prohibition Regulations extended the ban to all amphibole asbestos products. This meant that the other forms of such asbestos, i.e. fibrous tremolite, fibrous anthophyllite and fibrous actinolite were no longer permitted. The use of such types of asbestos had not been widespread however.

Products containing chrysotile (the sole serpentine form of asbestos) were banned only in November 1999, bringing to an end the importation of asbestos into the UK after over a century of such practice. Although the UK also has deposits of asbestos, and there is evidence of early exploitation of this resource (chrysotile fibres being used to strengthen clay or earthenware pots for example) the mineral has never been mined here on a commercial basis. The UK was, however, a massive importer of asbestos and had an extensive asbestos materials manufacturing industry.

Once asbestos had been confirmed as an extremely injurious material, moves commenced to remove such material (or at least that which had been damaged and thus posed the greatest risk to health). However, early asbestos removal exercises were often haphazard and some practices were downright dangerous, often posing more of a risk to health than would have been caused by leaving the materials in place. This led in 1980 to the formation of the Asbestos Removal Contractors’ Association (ARCA) who worked with the HSE and other interested parties to put together the Asbestos (Licensing) Regulations of 1983. These regulations required that only HSE licensed contactors be used for all work with asbestos insulation and sprayed coatings and that all such work would require 28 days pre-notification to the HSE or local authority.

In 1987, the Control of Asbestos at Work Regulations were published, replacing and extensively updating the Asbestos Regulations of 1969. The emphasis of such regulations was on the protection of workers involved in both the manufacturing and removal industries. New Control Limits and Action Levels (different for amphibole and serpentine asbestos) were set, along with the necessity to conduct formal exposure risk assessments and to produce effective plans of work prior to any work with asbestos materials. These regulations were amended in 1992 and again in 1998. Around the same time, the Licensing Regulations were amended to include asbestos insulating board (AIB) as a licensable material.

In 2002, the Control of Asbestos at Work Regulations were introduced and included Regulation 4, the duty to manage asbestos in non-domestic premises. This was to have a major impact. For the first time there was an implicit requirement for employers (or duty-holders) to identify where all asbestos was on their premises, assess the risk of exposure to people and implement a full management plan to control such risks. Also, all asbestos-in-air monitoring and bulk sample analysis could only be performed by a UKAS accredited laboratory. There was a lead-in period applied to some of the regulations but by May 2004, everyone had to be compliant.

In November 2006, the Control of Asbestos Regulations, revising the 2002 regulations and incorporating both the Licensing and Prohibition regulations, were introduced. The concept of licensable and non-licensable materials was done away with and replaced by a new terminology – licensable and non-licensable work; effectively much the same as before but emphasising the need to assess the exposure risk from all asbestos work, including work with materials such as asbestos cement which had always been regarded in the past as non-licensable. At the same time, a revised Control Limit for all forms of asbestos was introduced; 0.1 fibres per cubic centimetre of air (averaged over a 4-hour period). Controversially, the new risk-based approach to licensable work meant that work textured coatings no longer automatically required a licence. However, this was offset to some extent by the potential extension of the licensing net to many jobs, including some involving asbestos cement. Strangely, the Approved Code of Practice for CAR 2006, “Work with materials containing asbestos” includes a comment that most work with asbestos cement will not require a licence, seemingly contradicting some of the exposure assessment data (based on airborne fibre concentration only) published in earlier HSE guidance HSG 189/2, “Working with asbestos cement”.

Regulation 8 of CAR 2006 effectively states that ALL work with asbestos should be considered as licensable, EXCEPT work which fulfils the exemption requirements detailed in Regulation 3(2).

These requirements are:

·         Exposure to asbestos as a result of the work must be SPORADIC and of LOW-INTENSITY; and

·         Exposure to asbestos must be unlikely to exceed the CONTROL LIMIT.

·         Work cannot be regarded as being sporadic and low-intensity if the short-term exposure limit (STEL) of 0.6 fibres per cubic centimetre is likely to be exceeded.

In addition, the work must be either:

·         Short, non-continuous maintenance work (defined as any one person spending a maximum of one hour doing the job in any one week, more correctly any consecutive 7-day period, with the total time spent on the job by all persons not exceeding two hours); or

·         Work with asbestos where the asbestos fibres are well-bonded in a matrix with other materials (e.g. asbestos cement, bituminous products, resins, plastics, floor tiles or textured coatings); or

·      Encapsulation (including painting) of asbestos materials in an otherwise good condition (i.e. if slightly damaged, such work would be permissible only under the short-duration maintenance work criteria); or

·         The taking of bulk samples for asbestos analysis or air monitoring.

All asbestos materials must be disposed of as hazardous waste, defined in the Hazardous Waste Regulations of 2005 as any waste containing more than 0.1% by weight of asbestos. These regulations were amended in 2009 where the maximum amount of hazardous waste allowed to be disposed of before pre-registration is a requirement was raised from 200 kg to 500 kg per year. For waste produced by such unregistered originators, the disposal contractor is now regarded as the originator of that waste.

The Carriage of Dangerous Goods etc. Regulations apply to asbestos waste materials. These Regulations were restructured extensively in 2009 so that they now follow almost exactly the EU’s ADR regulations. The following information was extracted from the HSE’s web-site and is reproduced with full acknowledgement to the source:

·         Some asbestos waste (for example thermal insulation material, asbestos insulation board) is dangerous for carriage under UN numbers 2212 (transport category 2; the more hazardous) or 2590 (transport category 3).

·         It is also "special waste" for the purposes of waste disposal legislation which is enforced by the EA or SEPA as the case may be.

·         Accordingly it has to be properly packaged in UN certified packaging (usually double bagged in polythene bags that are tested and certificated) and properly consigned as for any other dangerous substance.

·         Carriage documentation is separate from waste disposal documentation, though some information may be shared. 

·         Note that the key information of proper shipping name, UN Number, class (in this case "9") and packing group (in this case same as transport category) preceded by the word "WASTE" must be together in the documents (ADR 5.4.1.1.3).

·         Asbestos cement products are covered by ADR special provision 168 and as such are not regarded as dangerous for carriage.

·         Articles such as lengths of pipe or ducting that have asbestos insulation inside or outside, or timber that has been used for enclosures should be treated as "manufactured articles" for the purposes of SP 168 provided that they are so wrapped in heavy gauge polythene (or similar) that asbestos fibres cannot escape. It follows that the way they are handled and transported should ensure that the integrity of the wrapping is not compromised.

·         ADR requires packages of asbestos to be carried in closed vehicles or containers (packing instruction P002, Special Provision PP37). The Control of Asbestos Regulations 2006 will apply. 

·         The preferred method is to use skips with lockable covers.

·         Skips meet the definition of "container" (ADR 1.2.1) so, unless the load limit exemptions apply (threshold 333 kg for blue/brown, 1000 kg for white asbestos), they must be marked as required by ADR 5.3.1.2 (UN Class 9 hazard placards on all four sides), and the vehicle must also display plain orange plates front and rear (ADR 5.3.2.1.1) - again subject to the small load exemption.

Substance	Application of ADR	Carriage requirements
Waste thermal insulation and AIB	UN 2212 or 2590 Class 9	Certified packaging (usually double polythene bags). Other aspects of Carriage Regulations apply. Special waste legislation
Asbestos in or attached to items such as pipes or ductwork	Treated as SP 168 exempted	Must be wrapped to prevent escape of fibres
Asbestos cement products (new)	Does not apply by SP 168	None
Asbestos cement products as waste	Does not apply by SP 168	Special waste legislation
Waste rubble or soil contaminated with asbestos	UN 2212 or 2590 Class 9	Certified packaging (available in up to 2 tonnes capacity bags) within skip or freight container. Other aspects of Carriage Regulations apply. Special waste legislation

·         Asbestos cement products are "special waste" and must be consigned under the relevant waste rules which include a "duty of care". That duty of care means, amongst other things, that duty-holders prevent escape of the waste whilst it is in their control.

Alexander Nicoll CCP (Asb.), AFOH

Senior Consultant, Asbestos Consultants to the Environment Ltd