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1 Document Name Page 1of 5 1. Introduction This guidance document outlines the standards that should be applied to glazing and glass within a school building or building used by school children. Since 1996, Regulation 14 of the Workplace (Health, Safety and Welfare) Regulations 1992 has made the requirement that every window or transparent or translucent surface in a wall, partition, door or gate should, where necessary for reasons of health or safety, be of a safety material or be protected against breakage of the transparent or translucent material; and be appropriately marked or incorporate features to make it apparent. This guidance considers the different types of glazing, classification methods and areas of critical locations within a school building including the actions that need to be taken to ensure that any high risk or critical locations in schools is identified and made safe. The standards and guidance within this report have considered the following documentation: BS :2005 Glazing for Buildings, Part 4: Code of practice for safety related to human impact Approved Document N of the Building Regulations Approved Document K of the Building Regulations Approved Document M of the Building Regulations Approved Document B of the Building Regulations Approved Document L of the Building Regulations The Workplace (Health, Safety and Welfare) Regulations 1992 [Regulation 14] HSE publication INDG212 Workplace health and safety: Glazing BS 6180:1999 Barriers in and about buildings BS 6206:1981 Specification for impact performance requirements for flat safety glass and plastics for use in buildings BS 476:1987, Part 22, Fire tests on building materials and structures. Methods for determination of the fire resistance of non-load bearing elements of construction BS 5516:2004 Patent glazing and sloping glazing for buildings 2. Classification methods BS 6206:1981 specification for impact performance requirements for flat safety glass and plastics for use in buildings requires that glass does not break or breaks safely, when subjected to a pendulum impact from a lead shot filled bag weighing 45kg. Three classifications levels are defined:- Class A when impact or is swung through a drop height of 1219mm Class B when impact or is swung through a drop height of 457mm Class C when the impact or is swung through a drop height of 305mm Class A safety glass (the highest rating) is not required by any regulation or standard related to human impact safety, but are part of the requirement for some types of barriers in BS 6180 barriers in and about buildings, where containment, guarding or prevention from falling is required.

2 Document Name Page 2of 5 BS 6206 defines the term breaks safely by reference to the outcome of the impact tests: Toughened glass breaks safely if the glass breaks into sufficiently small fragments after impact, i.e. if the weight of 10 largest crack free particles weighs less than the equivalent of 6500 mm2 of the original sample. Laminated glass, wired glass and filmed glass are deemed to have broken safely if, after impact, any glass fragments which fall off are not too large and it is not possible to pass a 75mm diameter sphere through any opening formed in the glass. Ordinary annealed glass or heat-strengthened glass do not break safely and can only pass the requirements if they do not break under impact test. 3. Classification marking BS 6206 requires that all glass classified as safety glass is marked to include the following information: An identifiable pane, trademark or other mark capable of identification through a suitable source. The type of material. The classification relating to impact test behaviour, Class A, B or C. These marks must be permanent and applied in a position, which remains visible after installation. All suppliers of cut sizes of safety glass should mark the glass in accordance with the requirements of the BS. 4. Commons types of glass Annealed glass: Ordinary glass, which immediately after it has solidified into the required form, is slowly cooled in controlled conditions to reduce the internal stresses within the pane. The material can be cut and worked and subsequently treated if required. Annealed glass is not classified as a safety glass, but if used in sufficient thickness, it can survive an impact test by not breaking. Toughened glass: Sometimes referred to as tempered glass, is produced by super heating annealed glass until it begins to soften. The surface of the glass is then rapidly cooled to create a state of high compression in the outer surfaces, which results in increasing the bending strength of the material by a factor of up to five times that of annealed glass. When broken the material fractures into small dice which are regarded as being virtually safe. Toughened glass needs to be cut and worked before it is processed. Heat strengthened glass: Produced in a similar manner to toughened glass, but the attained strength and potential for distortion is much less. The product is mainly used in situations where thermal stress may be a problem and additional strength is required. This material does not meet the safe break criteria and is not classified as a safety glass. Wired glass (Georgian wire): Despite popular belief and claims by some manufactures, the majority of wired glass is not classified as safety glass. Whilst the integral reinforcing wires may tend to hold the glass together under conditions such as fire exposure, they do not survive the impact test requirements of BS In recent years some manufacturers have

3 Document Name Page 3of 5 introduced heavier gauges of reinforcing wire, which serves to satisfy the requirement of impact test. It is essential that the true qualities of the product are identified and proven when specifying this material as safety glass. Laminated glass: Comprises of two or more layers of glass and or plastic material, which are attached to and separated from each other by some form of interlayer. The material is usually made of annealed glass, but toughened; heat strengthened or even wired glasses can be incorporated. The resultant material is no stronger than the glass it is made from, but on breaking, the fragments tend to adhere to the interlayer material and sharp edges are not exposed, thus rendering it relatively safe. The most common interlayer is PVB sheet, although there are not many available alternatives to the product. Due to the wide variety of interlayers and glass combinations available, it is not possible to give a blanket statement on the performance of laminated glass. Each specification needs to be assessed on its particular merits. 5. Requirement of safety glazing Any glass, plastics or safety films fitted in critical locations must comply with BS 6206 and be safety glazing. In all buildings, or parts of buildings, where the planned activity or use generate a special risk, all glazing regardless of position or height as defined by BS 6262 and section N1 of Approved Document N, shall be deemed to be a critical location and must comply with the glazing requirements set out in BS Glazed areas deemed to be special risk and in critical locations are: All glazing in special schools, Pupil Referral Units and Children Homes All glazing in gymnasiums, sports halls, or other areas where sports activities or ball games are likely to be played All glazing on unprotected elevations facing playgrounds and playing fields All glazing below 1800mm from floor level in all secondary schools and buildings used by secondary school children All glazing below 1500mm from floor level in all Primary schools and building used by primary school children All glazing in staircases below 1800mm from the treads and landing in all schools and buildings used by children Over time it is possible that the use of a particular building or areas of use change and may become areas of special risk in critical locations. It is the duty of the school to undertake regular risk assessments of all areas to check that the standard of safety glazing reflects the use of the building. These standards are also based on reasonable principles of behaviour by the building users. In school buildings, these critical locations remove the possibilities of doubt and the need to carry out a full glazing assessment, by assuming that all areas of glazing below 1500mm in primary schools and 1800mm in secondary schools are areas of glazing that are critical and warrant safety glass. Areas of glazing which are intended to provide containment or guarding, or where an engineered design needs to be applied, based on the particular merits of the presented scenario, these aspects of safety glazing are covered by Approved Document K of the Building Regulations and BS 6180 barriers in and about buildings.

4 Document Name Page 4of 5 6. Maintenance of glazing and safety glass Safety film to single glazing including the re-application of safety film: All glazing in critical locations are areas of special risk and not marked as have been filmed or being toughened or laminated glass or other such material deemed to comply with the requirements of BS 6206, must be treated with safety film to comply with BS All safety film must be fitted strictly in accordance with the manufacturer s instructions to ensure compliance with BS The film applied must be free from all dirt particles, fingerprints, scores, scratches, creases, air bubbles etc. and the edges must be free from lifting. The edge gap must be no more than 5mm. All treated panes must be suitably marked in accordance with BS Replacement of existing single glazing including where already filmed: All replacement glass must be a minimum of 6.4mm thick, class B, laminated safety glass to BS For example, Pilkington laminated safety glass. All panes must be suitably marked in accordance with BS Replacement glazing to existing fire doors and fire resisting screens and partitions: All replacement glass must be a minimum of 6mm thick fire resisting safety glass to BS 476: part and BS For example, Pilkington Pyro shield safety glass (Georgian wired). All panes must be suitably marked in accordance with BS New and replacement double glazed window units: All replacement and new doubled glazed window units must comprise of laminated safety glass to the outer pane and laminated safety glass with Low Emissivity (Low E) coating to the inner pane. For example, Pilkington K glass. All panes must be suitably marked in accordance with BS Alternatively, new double glazed units must comprise of toughened glass to the outer pane and laminated glass Low Emissivity (Low E) coating to the inner pane. For example, Pilkington K glass. In both cases the exact thickness and composition of the double glazed units will have to be in accordance with the Building Regulations Approved Document L and in locations where glazing requires fire resisting properties, in accordance with Approved Document B. 7. Inspection of safety film In order to perform as intended and offer the required level of protection it is important that safety film is in good condition. In areas of heavy use such as along corridors and the like, it is possible that safety film could become damaged or vandalised. It is the responsibility of a school to monitor the condition of safety film and film must be checked on a regular basis to ensure it is still in good condition. A visual inspection should consider film that is scratched, torn, peeling away from the window or milky or opaque in colour. These inspections should be recorded, and ideally form part of any glazing risk assessment. Any safety film defects found during an inspection must be addressed and work carried out to eliminate the risk.

5 Document Name Page 5of 5 Most applied safety film will come with a manufacturers and installers warranty and depending on the type of film applied it is not uncommon for safety film to have a 10 year guarantee (if the film is applied internally). External applied film will have a reduced life and this will be reflected in the likely warranty period given. In some cases any warranty may be only for 2 years from the date of fitting. Schools must ensure that at the end of any warranty periods all safety film is either tested or re applied to ensure the required level of protection is provided or glazing replaced with safety glass (minimum 6.4mm thick class B laminated safety glass to BS 6206). 8. Overhead glazing With sloping or overhead glazing, it is generally regarded as appropriate to install glass, which will either tend to stay in place when broken or which will fracture into relatively small pieces that are deemed to be less harmful. Laminated, toughened or safety wired glass fall into these categories. BS 5516 patent glazing and sloping glazing for buildings is the only regulation or standard, which gives any recommendation about the type of glass to use in roofs. In general terms the BS supports the above statement but advices that toughened should not be used over swimming pools and that consideration should be given to the use of heat soaked toughened glass in situations subject to spontaneous fracture due to thermal shock. Heat soaked toughened glass has a much lower risk of fracture than ordinary toughened glass as the manufacturing process leads to the reduction of incorporated impurities such as nickel sulphide. 9. Manifestation Another associated aspect of safety glass in use is the provision of manifestation to raise awareness of the presence of glass, which may otherwise be difficult to see. Manifestation is more to do with avoidance of the risk rather than dealing with the consequences by the more passive role of using appropriate materials. In order to comply with the requirement of Approved Document N, section N1, advises that manifestation may take various forms such as broken or solid lines, pattern or company logos, which should be applied at 1500mm above, floor level and should be in critical locations. Critical locations are defined as including uninterrupted areas of transparent glazing, which form or are part of internal or external wall and doors of buildings. Additionally, Approved Document M, section M1 and M2, requires all glass doors to be clearly defined with manifestation on the glass at two levels and contrast visually with the background seen through the glass. 10. Further advice and guidance on risk assessment Before carrying out any risk assessment of your glazing ensure that you have received the appropriate health and safety competence in risk assessing glazing. For further advice and guidance on the matters or any aspect of glazing safety please contact your Area Building Surveyor or Mark Norrell, Building Surveying Manager on