ASBESTOS IN ‘CLASP’ OR
SYSTEM BUILT SCHOOLS
GUIDANCE TO DIVISIONS FROM THE NUT
Asbestos has been the main cause of occupational ill health from about 1950 onwards
and is still the greatest single work-related cause of death from ill health. Past exposure is responsible for about 4000 people dying from asbestos related cancers every year.
This figure is expected to rise over the next ten years and then decline.
Asbestos gives off very small and fine fibres which can be breathed in easily. They can
remain in the lungs, or settle in the linings of the lungs and the chest cavity, for long periods after exposure and their presence can lead to many asbestos-related diseases.
Asbestos containing materials (ACMs) were widely used in the construction of post war
schools; and continued despite growing awareness of its health risks. Only those
schools built since 2000 can safely be assumed to contain no ACMs.
Asbestos in CLASP and other System Buildings Working Group
In December 2006, the Health and Safety Executive (HSE) turned its attention to
asbestos risks in „CLASP‟ or other system built schools. Following some incidents of
asbestos exposure in schools of this type during 2006, the HSE set up the Asbestos in
CLASP and other System Buildings Working Group to achieve a number of objectives,
? to ensure that all school education duty holders are aware of the asbestos issues
as they affect CLASP and other system built schools;
? to obtain information from school education duty holders to establish their level of
understanding of the issue and application of the advice for remedial action given
by HSE ;
? to evaluate the effectiveness of the remedial action advised by HSE;
? to obtain information on the level of compliance with Regulation 4 of the Control
of Asbestos At Work Regulations (CAWR) 2006;
? to share information and guidance with the duty holders of other similar system
built schools; and
? to provide further information and guidance to education duty holders.
Whilst it is true that CLASP-type buildings contain large quantities of asbestos, the NUT
has reservations about the narrow remit for the Working Group. It is particularly vital that
the work of the group does not lead to a widespread perception that the principal
concern as regards asbestos in schools lies within CLASP and system built schools
alone. Asbestos is a problem in the vast majority of schools – of whatever age and building type.
The NUT has consistently argued that the HSE should focus on the issue of asbestos in
schools generally. Such a strategy should include:
? raising awareness amongst school managers and maintenance staff;
? publicising examples of good asbestos management practice;
? the provision of sector-specific guidance on dealing with asbestos in schools; and
? a thorough examination of the role and provision of occupational health care in
respect of those who may have been exposed to asbestos fibres in schools1.
Notwithstanding the points made above, the NUT is keen to maximise the benefits which
might be afforded from the HSE‟s current focus on CLASP-type buildings. The
remainder of this briefing explores the background issues surrounding these structures
and the means by which problems might be addressed.
Further NUT guidance on tackling asbestos in schools can be found at
‘CLASP’ or system built schools
The majority of the 13,000 schools built in England and Wales between 1945 and 1975
were system/modular built. A large number of these were erected according to the
Consortium of Local Authority Special Programme (CLASP) or the Second Consortium
of Local Authorities (SCOLA) systems. They were designed to be of standard
construction using a relatively light-weight steel girder construction with panel infill.
Large quantities of asbestos were used in their construction, in such diverse locations as
ceilings, partition walls, tiles, heaters, water tanks, pipes and window frames.
One of the main reasons for the widespread use of asbestos was the cheapness of the
building materials employed in CLASP-type structures. Most system built schools of this
type had flat roofs which were projected to remain serviceable for 15 -20 years – a shelf-
life which has long since expired. Water ingress is a common problem, as is the
deterioration of window frames, roofs and guttering.
A lack of maintenance in many schools has led to general deterioration of the fabric; and
the asbestos containing materials (ACMs) have suffered as similar fate. Worn or
damaged ACMs represent a serious risk to health, and cannot simply be patched up and
given a fresh coat of paint as might be the case with other building materials.
1 This point is important for a number of reasons. The HSE has stated in respect of teachers that
“there are too many deaths among a group which are supposed to have had very little asbestos
exposure”, yet its advice to those who may have been exposed is currently unclear.
There are over 3,000 CLASP buildings still in existence. „Scape‟, the trading arm of CLASP, holds information from which it is possible to deduce with reasonable accuracy the types of asbestos used in CLASP structures of different ages. Consequently, an estimate can be made of how many are likely to contain sprayed asbestos insulation, and how many are likely to contain crocidolite and amosite. Those wishing to find out more about this data should, in the first instance, contact the NUT Health and Safety Unit at Hamilton House.
Other types of modular school buildings also exist. About 6,000 system built schools were constructed between 1945 and 1975, a significant proportion being CLASP structures and the remainder being built to alternative system/modular designs.
It should be noted that asbestos containing materials (ACMs) will almost certainly be found in conventionally built schools, and schools that were refurbished. Some of those are of a similar design concept to CLASP buildings.
Asbestos was used in a range of ways in system built schools, but chiefly in cement, sprayed coatings, lagging and asbestos insulation board.
Cement can be combined with about 15 per cent asbestos to form a rigid sheet less than five millimetres thick. Alternative materials, such as iron, require a much thicker sheet in order to achieve the same strength. Given that asbestos was cheap, plentiful and light to transport, construction companies were inclined to see asbestos as the building material of choice. Furthermore, its lightness made it easier to work with and manipulate – notwithstanding the acute risks to health involved in so doing. Asbestos cement –
mainly containing „white‟ or chrysotile asbestos - was used extensively in CLASP-type
buildings, particularly as sheeting on walls and roofs, slates, tiles, cold water tanks, gutters and pipes. Fibres are released from such materials with age; when the material is damaged; and during routine maintenance activities such as drilling, sanding, wire brushing and machine sawing. All these activities can produce dangerous concentrations of asbestos dust.
Sprayed coatings are probably the most lethal way in which asbestos was used. It was common for many sprayed asbestos products to contain up to 85 per cent asbestos, much of it the crocidolite form. Between 1935 and 1971, it was used extensively in public buildings for acoustic and thermal insulation and fire protection of structural steel work. It was common in system-built council housing and schools; from boiler houses and ceilings to balconies and walkways. It is not unusual to find this material to be soft, friable and therefore extremely dangerous.
Lagging is frequently just as deadly. It was used around heating pipes and boilers especially in public buildings such as schools and hospitals. It has been found to give very high dust levels in service ducts where it is easily disturbed during maintenance activities.
During the 1950s, 1960s, and 1970s amosite was a favoured component of insulation boards which were used in ceiling tiles, curtain walling, partitions, and fire proof panels. They are found extensively in system-built schools. Asbestos insulation board (AIB) was also used in stairways, heating ducts, door linings and heating units. Insulation boards from this period often have a soft greyish appearance, and typically contain 16-25 per cent asbestos.
Asbestos exposure incident in a CLASP school
In 2006, asbestos contractors carried out some removal work at a school in Wales. On
completion of their work, they failed to obtain asbestos fibre levels below the „clearance level‟ of 0.001 fibres per millilitre (f/ml) when - as part of deliberate disturbance - they
struck parts of the steel clad columns in the room.
Subsequently, scientific experts appointed by the Health and Safety Executive (HSE)
2arrived at the school to conduct more detailed tests. These demonstrated that when
some steel clad columns in the room were struck, airborne fibre levels of amosite
reached 0.44 fibres per millilitre (f/ml) on a static sampler. This is 44 times higher than the „clearance level‟ of 0.001 f/ml – the legal limit for the room to be occupied.
The HSE concluded that there was a potential for significant asbestos exposure to
persons in the room from damaged or poorly sealed columns being disturbed in the
course of normal day to day activities. It further considered that such levels of asbestos fibres could be released when the wind blew, a door was slammed or the wall was
knocked. It was therefore reasonable to assume that these levels were a common
From the information above, it has been calculated that every time a door was slammed or the wind blew in such a classroom, its occupants were potentially breathing in more than quarter of a million amosite fibres per hour.
HSL took several hundred air samples to measure fibre levels in 20 different CLASP
schools. To simulate normal activity they hit the walls, slammed the doors and windows and sat on the window sills. Out of the 33 air samples carried out during this activity only eight were within the legal limits for classroom occupation. All the other readings were above the legal limit, some by a large margin. The mean level was nine times higher than the legal limit.
After remediation work had been carried out in some of the CLASP schools that were
tested, the airborne amosite fibre levels remained above the clearance limit.
Measurements taken while the schools were occupied revealed that the mean
background level was ten times higher than the normal background level in a school with asbestos in good condition, whilst the highest background level was forty four times higher.
It must be assumed that these peak levels had been present for some time. As the
schools involved in the HSL test were built in the 1960s and asbestos off cuts and debris had been swept into the wall voids and remained in the ceiling voids, it is possible that the peak levels had been present for a very long time - perhaps for decades.
The measures deployed by HSL to reduce the asbestos fibre readings to more
acceptable levels included the use of silicone sealant and sticky tape – despite which
expedient the asbestos fibre levels continued to remain above the clearance level in some of the schools. In discussions with the HSE, the NUT has expressed its
dissatisfaction with the adoption of such strategies, arguing instead that such ACMs should be completely removed from the school.
2 The tests were conducted by Health and Safety Laboratories (HSL) – the scientific research arm of
Asbestos in CLASP and other System Buildings Working Group
In the light of a number of incidents involving the release of asbestos fibres in CLASP-type schools, the HSE and the DfES convened a working group with the specific task of examining the question of asbestos control in CLASP schools. The group included
representation from the Local Government Employers, NASUWT, HSE and DfES. The
HSE was at pains to insist that no teachers or children had been exposed to dangerous levels of amosite fibres in these schools; but that a review of available guidelines and advice for CLASP schools and local authorities was prudent.
The HSE has chosen to concentrate on the release of asbestos fibres via gaps in steel-clad columns – a common architectural feature of such buildings. This may lead to the
formation of the view that fibre release from column casings is the pre-eminent cause of concern in system-type buildings. Such a view would be erroneous - and the NUT
regards the HSE‟s decision to focus on such a specific issue as unfortunate. Much of
the damaged, friable asbestos is hidden behind walls in CLASP schools and large
quantities of asbestos are an integral part of the structure of the building.
The HSE does not share the NUT‟s view that complete removal of ACMs is the optimum
solution to the problem. It is not disputed that the complete removal of ACMs from a school - followed by refurbishment - would undoubtedly incur considerable expense. On the other hand, measures which fall short of complete removal will always leave a
degree of uncertainty as to their effectiveness. In some cases, no action will be taken at all. This occurs chiefly because senior staff lack the appropriate training in complying with their „duty to manage‟ asbestos set out in the Control of Asbestos at Work
Regulations 2006. It is to be hoped that the Working Group can offer a way forward in this regard.
In other cases, encapsulation programmes might be put in place, as suggested in the HSE advice appended to this briefing. Such remedial work, whilst preferable to inaction, remains highly unsatisfactory. Encapsulation – even if done well,
? should only be a temporary measure pending the instigation of a proper asbestos
? may be accidentally damaged or vandalised, thus re-exposing the original ACMs;
? may result in poor awareness of the presence of ACMs, leading to possible
exposure during subsequent maintenance or repair work.
The NUT acknowledges that in some cases encapsulation might be an acceptable short
term expedient. The principles of risk assessment require, however, that employers should seek firstly to remove all risks rather than to reduce risks or institute protective measures.
Beyond the Asbestos CLASP Working Group
Whilst welcoming any development which might raise awareness of the issues
surrounding asbestos in schools, the NUT does have reservations about the remit of the
Asbestos in CLASP and other System Buildings Working Group. In particular, the NUT
remains deeply concerned that the narrow remit of the Group. Concentrating solely on
CLASP and other system built structures might lead dutyholders to imagine that
asbestos problems are largely confined to such schools, when the reality is that any
school built before 2000 is highly likely to contain at least some asbestos.
Secondly, a further circumscription is placed on the scope of the Group‟s work in that it
has dealt almost exclusively with the management of risks arising from damaged ACMs
behind the casing of steel-clad columns. No detailed advice or information has been
prepared about ACMs in any other locations within CLASP structures. Once again,
some dutyholders might form the view that so long as they have had their steel columns
checked and, if necessary, repaired, they have met the requirements of the asbestos
regulations. This would be a wholly erroneous belief.
Thirdly, the NUT believes that proper health surveillance of those exposed, or who may
have been exposed, is of paramount importance. Where dutyholders carry out
inspections and find evidence of exposed ACMs, which have resulted in asbestos fibre
releases above the clearance limit, they should issue health advice to those at risk,
which should include having the incident recorded by a GP for future reference. Whilst
the prognosis for mesothelioma is always poor, the earlier it is diagnosed the longer a
patient‟s life can be prolonged.
On a more positive note, the guidance on asbestos management in CLASP-type schools
proposed by the HSE is most welcome. The NUT has argued, however, that what is
especially needed by heads, governors and senior managers is training on the
fundamental issues of asbestos management in educational settings. The NUT has
asked the HSE to consider the co-ordination of some regional-based training courses on
asbestos management for dutyholders in the education sector. The Union awaits the
response of the HSE with interest.
In the meantime, Health and Safety Advisers should continue to follow existing NUT
policy when dealing with asbestos issues in schools. The following page lists a
comprehensive range of recent guidance on the matter for ease of reference.
NUT Health and Safety Unit – July 2007
Other NUT Health and Safety Briefings on Asbestos in Schools
“Asbestos in Schools” www.teachers.org.uk/resources/word/ASBESTOS-NUT-H&S-BRIEFING.doc
“Asbestos and Textured Decorative Coatings: The 2006 Regulations”
“Asbestos – Focus on Removal in 2007”
DCSF guidance on pinning, stapling and tacking display materials to school walls or
ceilings that might contain asbestos is available on the „Teachernet‟ website at
“Asbestos – An Important Message for Schools” www.hse.gov.uk/asbestos/schools.pdf
“Asbestos in CLASP and other System Buildings”, as appended to this briefing, is at
APPENDIX: ASBESTOS IN ‘SYSTEM BUILT’ SCHOOLS
Control of Asbestos Regulations 2006
Information note for education authorities and governing bodies
as duty holders
1. This briefing note gives information about asbestos in CLASP school buildings
built between 1945-1980. However, it should be noted that the same issues are
faced in all types of „system built‟ schools constructed during the same period.
The names of other known systems are given in the further information sector at
2. It sets out the action that education authorities and governing bodies as duty
holders (see para 12) are required to take to manage asbestos in CLASP built
schools of the period defined in para 1 above.
3. Local Authorities and Governing Bodies as duty holders should already be
managing the risks from asbestos present in schools within their control.
However, there is new information about the potential for asbestos fibre release
from damaged column casings in „system built‟ schools. This damage, which
includes „cracks‟ and „gaps‟ may have occurred as a result of previous alteration,
removal or direct physical impact on the casing.
4. Asbestos containing materials (ACMs) were widely used in „system built‟ schools
constructed during the period 1945 – 1980. Within all buildings of the period,
ACMs were used extensively on pipe work, heating plant and other services, and
as ceiling tiles and wall panels. For example many of the „system built‟ schools
used lightweight steel frames that required fire protection, particularly in ground
floor locations of multi-storey buildings. Asbestos insulating boards (AIB) were
used for this purpose. It is important to note that the building systems developed
over time and details were revised and specification of materials changed. This
has led to variation in the types and locations of ACMs.
5. CLASP (Consortium of Local Authorities Special Programme) was formed with
the purpose of developing a method of building, which did not rely on traditional
building skills, to provide fast and efficient permanent school buildings. The
systems were developed as either proprietary contractor owned products or Local
Authority Consortia designs. There are more than 1400 CLASP built schools in
the UK, distributed among 89 LEA/Children‟s Services Departments.
Independent schools own a small number of CLASP buildings.
6. Marks 2, 3, 3b, 4, 4b and early 5 CLASP buildings built between 1945 and 1980
may all contain asbestos materials, particularly mark 4 and 4b. Other „system
built‟ schools will have used similar construction techniques and are also likely to
contain asbestos (see para 25).
7. In these types of school buildings, some metal casings around the steel columns
may be insulated with AIB. The AIB may only be present in those that provide fire
protection. It may be fixed directly to the column or glued to the metal casing.
ACMs may also be found in blind boxes to the windows.
8. ACMs may also have been used in these buildings as unrecorded substitute
items where there were material shortages and/or poor supervision. In addition
excess or waste ACMs may have been left hidden inside columns or panels.
Consequently, asbestos may be found in some unexpected locations and the
presumption should be that ACMs would be present in other concealed areas.
9. Education duty holders have a responsibility under regulation 4 of the Control of
Asbestos Regulations (CAR) 2006, to manage the risks arising from asbestos in
the school buildings under their control. Duty holders must take reasonable steps
to find ACMs in their premises and to check its condition. Duty Holders must
provide information on the location and condition of the asbestos to those people
who are liable to disturb it. The information is particularly relevant to contractors
and others who undertake maintenance and refurbishment work or other work,
which disturbs the fabric of the building, e.g. cable installation.
10. ACMs pose no threat to health if intact, undamaged and not disturbed. HSE
recommends that ACMs are left in place where they are in good condition and will
not be damaged by occupational activities. These materials do not present a risk
to the building occupants.
WHO HAS THE DUTY TO MANAGE ASBESTOS IN SCHOOLS?
11. For the majority of schools it is the employer who has an obligation to manage
asbestos as a „duty holder‟ under Regulation 4 of the Control of Asbestos
Regulations 2006. Who the employer is can vary with the type of school.
? For community schools, community special schools, voluntary controlled
schools, maintained nursery schools and pupil referral units the employer
is the Local Authority.
? For foundation schools, foundation special schools and voluntary aided
schools, the employer is usually the Governing Body.
? For independent schools, the employer is usually the Governing Body or
ACTION REQUIRED BY DUTYHOLDERS
12. Local authorities and Governing Bodies as school employers and duty holders
must ensure the following action is taken to manage asbestos in schools.
(i) Identify all CLASP (and other building systems) school buildings,
particularly mark 4 and 4b as a priority, but also include CLASP schools
built between 1945 and 1980. Assistance on identifying CLASP buildings
can be obtained from SCAPE (see para 24). Carrying out a desktop
survey of building plans can also help with this but note that these plans
may not always be wholly accurate.
(ii) Where the building is a CLASP or other system design, visually inspect
(see para 14 on priority) the full lengths of all the column casings for
cracks, gaps or damage, including the back of the casings as there is
potential for gaps to occur here as well. Also inspect the top and bottom
of the column casings.
Figure 1 - DIAGRAM OF CLADDING AROUND COLUMNS
AIB adhered and or
screwed to cladding
Cladding (two u sections)
Gap where two sections
of cladding join
(iii) Seal all gaps to the column casing, skirting and walls to enclose dust and
debris with a silicone sealant. UPVC strips can be used as finishing over
the top of the gaps using the same sealant.
(iv) Visually check to ensure that the sealing is effective.
(v) Following remedial works make sure that the area is thoroughly cleaned
and visually inspected to ensure that there is no dust or debris remaining.
Airborne monitoring can be carried out for reassurance purposes or if there
is doubt over the effectiveness of the enclosure.
(vi) Note and record the action taken.
13. As the above action does not involve any direct work with ACMs, a competent
person rather than a licensed asbestos contractor can carry out the work as long
as they have been trained and equipped as described in paras 17 and 18 below.