Last reviewed 28 August 2013

Even though the use of asbestos is now banned, exposure to asbestos fibres is the single greatest cause of work-related death in the UK. Now, almost all exposure arises from asbestos in buildings, with building maintenance personnel being the workers most likely to be exposed. In this article, Gordon Tranter discusses the risk assessment of exposure of maintenance workers to asbestos.

Asbestos comprises a set of six naturally occurring silicate minerals that have been widely used. Three main types of asbestos — crocidolite (blue), amosite (brown) and chrysotile (white) — have been used commercially. Asbestos was popular among manufacturers because of its sound absorption, average tensile strength, resistance to fire, heat, electrical and chemical damage, and affordability. At least 5000 different products have been manufactured from asbestos, with many products being used in the construction of buildings.


Asbestos is a category 1 human carcinogen, although asbestos material in good condition does not pose a risk to health. It is when asbestos is in the form of fibres that can be inhaled that it is hazardous. Every year, inhalation of such fibres is responsible for more than 4000 deaths in the UK. Exposure to asbestos fibres can cause four main diseases.

  1. Mesothelioma, a cancer of the lining of the lungs, which is always fatal.

  2. Asbestos-related lung cancer, which is almost always fatal.

  3. Asbestosis, which scars the lungs and, although not always fatal, can be a very debilitating disease.

  4. Diffuse pleural thickening, a thickening of the membrane surrounding the lungs, which in some cases, can restrict lung expansion and lead to breathlessness.

The effect of exposure to asbestos fibres is cumulative and it can be anywhere between 15 and 60 years after the exposure before any symptoms become apparent.

Asbestos in buildings

It is now illegal to use asbestos in the construction or refurbishment of any premises, but there are still many thousands of tonnes remaining in buildings. Building materials containing asbestos were widely used from 1930 to around 1980, particularly from the 1960s onwards. Products made from asbestos-containing materials (ACMs) that have been used in buildings include: barge boards; chimney cowls; ducts; eaves; fascias; fire dampers; flue terminals and risers; gables; plenums; soffits; stud partitions; and sandwich partitions.

In 1985, the use of asbestos materials containing either blue or brown asbestos was prohibited except for products already in use. The use of white asbestos, particularly in asbestos cement, continued in new houses and the refurbishment of existing houses until 1999.

The duty to manage asbestos: the law

In order to manage the risk from asbestos in non-domestic premises, the Control of Asbestos Regulations 2012 (CAR 2012) (SI 2012 No. 632) Regulation 4: Duty to manage asbestos in non-domestic premises, requires the dutyholder for non-domestic premises to undertake the following.

  • Ensure that a suitable and sufficient assessment is carried out as to whether asbestos is or is liable to be present in the premises.

  • Where the assessment shows that asbestos is or is liable to be present in any part of the premises, the dutyholder must:

    • assess and record the risk from that asbestos

    • prepare a written plan identifying the measures that are to be taken to manage the risk in those parts of the premises concerned; the plan should be reviewed and revised at regular intervals or if the circumstances change.

When construction work, including refurbishment, takes place in a non-domestic building, the Construction (Design and Management) Regulations 2007 (CDM) require arrangements to be in place to deal with asbestos. These arrangements involve a risk assessment so that the CDM client can provide contractors who are bidding for the work with project-specific information about the presence of asbestos.

The duty to manage asbestos: the duty holder

The CAR 2012, duty to manage asbestos in non-domestic premises places the duty on the duty holder. The duty holder in non-domestic premises is:

  • every person who has, by virtue of a contract or tenancy, an obligation of any extent in relation to the maintenance or repair of the premises or any means of access or egress to or from them

  • where there is no such contract or tenancy for any part of the premises, every person who has, to any extent, control of that part of the premises or any means of access or egress to or from them.

The risk assessment

The assessment of the risks from exposure to asbestos fibres in non-domestic buildings requires several steps.

  1. A survey to be undertaken to determine whether there are any ACMs in the building, the amount and their nature.

  2. An assessment to be carried out of the risks from any ACMs in the building.

  3. A decision to be made on how to manage the risks from the ACMs. 4. Implementation of the plan.

  4. A review of the plan.

This article concentrates on the risk assessment of the exposure to asbestos fibres of maintenance workers and tradesmen, such as plumbers, electricians, carpenters, cleaners, painters and decorators, and builders who may disturb the fabric of buildings during the course of their work.

The survey

Before decisions can be taken on the management of asbestos, information is needed on whether asbestos is, or is likely to be, present in the building. Consequently, the first step is to carry out a survey to determine:

  • whether ACMs are present

  • the form the ACMs are in

  • where the ACMs are and how much there is

  • how accessible the ACMs are

  • the condition of the ACMs and their ability to release fibres

  • the asbestos type, either by sampling and analysis or by presumption.

The survey can be carried out either by in-house personnel or by a third party. The surveyor must be competent to carry out the work required, and must have sufficient training, qualifications, knowledge, experience and ability necessary to carry out the survey. In addition, a surveyor must have the ability to recognise his or her limitations. He or she should have knowledge of building construction, construction methods, fire protection and the various uses of buildings, and the range of building components and structures that contain asbestos. The Health and Safety Executive (HSE) strongly recommends the use of accredited or certificated surveyors for asbestos surveys and has published guidance, Asbestos: The Survey Guide (HSG264).

There are two different types of survey — management surveys, and refurbishment and demolition surveys. A management survey is the standard survey that is required during normal occupation. A refurbishment or demolition survey should be carried out prior to a building (or part of it) being upgraded, refurbished or demolished, and should locate and describe, as far as reasonably practicable, all ACMs in the area where the refurbishment work is to take place.

The survey will usually involve sampling and analysis to confirm the presence or absence of ACMs and to identify the type of asbestos. However, a management survey can also involve presuming the presence or absence of asbestos.

A record of the location

Where the survey shows that an ACM is or is liable to be present in the building, an asbestos register or log and a building plan detailing the location of the ACMs and their condition should be prepared. This should be used to carry out a suitable risk assessment and to develop and implement the management plan.

The assessment

Once the survey has been completed, an assessment of the risk of anyone being exposed to asbestos fibres should be carried out for each of the places in which there is an ACM. This should provide the information necessary to formulate the management plan and prioritise the actions.

The assessment will consider a number of factors.

  • The ACM.

    • Asbestos type — crocidolite is more hazardous than amosite, and both are much more hazardous than chrysotile.

    • Product type — eg asbestos insulating board, lagging, floor tiles, textiles, composites, textured coatings, sprayed coatings, loose asbestos in ceiling or floor cavities. Some ACMs are very unlikely to cause harm, eg asbestos cement in good condition does not easily release fibres.

    • Condition — extent of damage or deterioration.

    • Surface treatment — priority assessment.

  • The location.

    • Occupancy — number of occupants, frequency of use, average time in the area.

    • Accessibility and amount.

    • Activities near the ACM and the potential for damage. This should consider the activities of maintenance workers.

The HSE has a scoring tool on its website that can be used to help evaluate the extent of the risks and can be used to prioritise the actions required.

Managing the risks: The management plan

Once the survey has been carried out and the risks from the ACMs assessed, a management plan should be produced. The plan should put in place and record the actions and control measures that take account of the risk assessment, and prevent or minimise the risk from exposure to asbestos.

In developing the management plan, the duty holder will need to use the risk assessment findings to decide whether to remove or to manage the ACMs. While one’s natural instinct might favour removal, it should be remembered that the removal of ACMs can be dangerous. It can cause fibres that were previously in a “safe” state to be released into the atmosphere. It is usually safer to manage ACMs that are in a good condition and are not likely to be damaged, worked on or disturbed. On the other hand, if the asbestos is in poor condition or is likely to be damaged or disturbed, the decision is whether to repair, seal, or enclose the asbestos so that it cannot release fibres and is therefore safe unless it is disturbed, or to remove it.

ACMs that are not removed have to be managed. Steps should be taken to raise awareness and understanding of asbestos with all staff and to provide them with information about the location of ACMs within their working areas.

Maintenance workers and tradesmen

Procedures should be in place to inform anyone who is liable to disturb ACMs about their location and condition. There should be arrangements and procedures in place so that work that may disturb ACMs complies with CAR 2012.

The procedures and arrangements for managing any ACMs that have not been removed are particularly important for workers who may disturb the fabric of buildings during maintenance, refurbishment, repair, installation and related activities, and who may be exposed to asbestos if they unknowingly work on ACMs or carry out work without taking the correct precautions.

The asbestos register and/or building plan showing the location of any ACMs should be made available to employees and visiting tradesmen to ensure they will not inadvertently encounter an ACM and disturb it. Employees and visiting tradesmen can be alerted to the presence of ACMs by labelling the ACM with the approved asbestos warning sign. The problem with such labels is that they can fall off or become unreadable, so they should be inspected regularly.

Checks should be made to confirm that all companies providing tradesmen have trained their employees in asbestos awareness. Any work on ACMs must be approved, and maintenance workers and tradesmen who find they need to work on an ACM, eg drilling a hole in asbestos cement to hang a fitting or route an electric cable, must not carry out the work unless the work has been approved.

Work on asbestos

Most asbestos work must be undertaken by a licensed contractor, although lower risk work does not need a licence. To be exempt from needing a licence the work must be:

  • sporadic and low intensity

  • carried out in such a way that the exposure of workers to asbestos will not exceed the legal control limit

  • a short, non-continuous maintenance task with only non-friable materials, or it is a removal task where the ACMs are in reasonable condition and are not deliberately broken up, and the asbestos fibres are firmly contained within a matrix.

Some non-licensed work, where the risk of fibre release is greater, requires notification of the work, record keeping and, after April 2015, medical examinations. This work is known as notifiable non-licensed work (NNLW).

Maintenance workers and tradesmen may need to carry out unlicensed work, for example: drilling holes in asbestos cement and other highly bonded materials; removing asbestos cement debris; removing asbestos-containing floor tiles, mastic and sealing; and enclosing an ACM. This work should comply with the requirements of CAR 2012 — a risk assessment, plan of work, information, instruction and training, and prevention or reduction of exposure to asbestos. This involves carrying out a risk assessment.

The assessment should determine whether the work fulfils the criteria for the exemption from needing a licence and, if so, whether it is NNLW. This will involve considering the type of work and whether the asbestos is friable, how firmly it is bonded in a matrix, and its condition.

The HSE has published guidance, AO Asbestos Essentials: Advice on Non-licensed Work with Asbestos, which is supported by task sheets that describe good practice for several specific low-risk tasks. It must be emphasised that the task sheets should not be used without assessing whether the task sheets describe the task to be carried out and whether there are additional factors to be considered.


The assessment of whether asbestos is present in the premises should be updated whenever work has been done on ACMs and, at least once a year, the ACMs should be checked to make sure they have not deteriorated. The management plan should be reviewed and revised at regular intervals, and without delay if there is reason to suspect that it is no longer valid, or there has been a significant change in the premises.