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Glass Safety Guide - page 2B. Requirements for critical locationsIn accordance with BS 6262 Part 4, there are four recommended solutions to the problem of glazing 'critical locations' 1. Safe BreakageFor doors and door side panels, the glazing used should not break, or should break safely in accordance with Class C of the standard impact test BS 6206 (1981) if 900mm wide or less, or Class B if wider than 900mm For other low level glazing the pane should comply with at least BS 6206 Class C. Use laminated or toughened glass, or plastics glazing sheet, or wired glass, that meet BS 6206, or glass with plastic film applied so the pane of glass with film meets BS 6206. For unbacked mirror glazing accessible to impact from one side only, the pane should comply with BS 6206 Class CO if equal to or less than 900mm wide or Class B0 if wider than 900mm. Unbacked glazing either has no backing behind its entire area, or has a backing which does not retain its integrity or is cracked or broken when tested as described in BS 7449 (1991): Appendix A. If the mirror glazing is fully backed by a solid material, like a wall or timber wardrobe door and it is securely fixed so that there is space of no more than 25mm between the mirror and the backing material, then a glass which does not comply with BS 6206 may be used. 2. Small PanesOrdinary annealed glass may be used in small panes up to a maximum width of 250mm and an area not exceeding 0.5m2. Such glass must not be less than 6mm in thickness, except in the case of traditional leaded lights and copper lights, where 4mm can he used.
Diagram 2: Dimensions and areas of small panes 3. RobustnessRobustness refers to the strength of the glazing forming fronts to non-domestic buildings such as shops. showrooms, offices. factories and public buildings.
Table 1: Nominal thicknesses and pane sizes for critical locations Some glazing, such as polycarbonate, is inherently strong. Annealed glass that does not normally comply with BS 6206 can gain robustness with increased thickness. Annealed glass may only he used in critical locations, therefore, when the nominal thickness and dimensions are as listed in Table 1 above. 4. Permanent Screen ProtectionIf the glazing is installed behind a permanent robust screen, it need not itself comply with any other safety requirements provided that the protecting screen:
Diagram 3: Permanent screen protection requirements |