Glass > Pendulum body impact test

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Categories: Performance: Glass


This test shows whether the glass breaks and, if it breaks, whether it breaks safely.

In the UK context this is a test to establish whether a glass is a 'Safety glass'.


EN 12600Glass in building — Pendulum test — Impact test method and classification for flat glass
BS 6262-4Glazing for buildings — Part 4: Code of practice for safety related to human impact


Method of test

A soft body impactor comprising two tyres and a weight is allowed to impact the glass by swinging against it. Different drop heights are used to vary the severity of the test. The test method is described in full in EN 12600.

An IGU may either;

  • Be tested as an IGU
  • Classified on the performance of the individual panes
  • In the second case either;

  • The class of the lowest performing glass is used, or
  • The perfomance of each may be given in the sequence that they are given in the product description



    Classification of glass is given in the form α(β)φ where:

  • β is the mode of breakage
  •     Mode A - Separate fragments with sharp edges exposed
        Mode B - Fragments held together with no sharp edges exposed
        Mode C - Disintegradtion into small dice

  • α is the drop height class at which the glass either did not break or broke safely
  •     Class 1 = 1200 mm
        Class 2 = 450 mm
        Class 3 = 190 mm

  • φ is the drop height class at which the glass did not break or broke safely and remained in place
  •     Class 1 = 1200 mm
        Class 2 = 450 mm
        Class 3 = 190 mm

    CE Marking

    UK Regulations require glass in critical areas to be a 'safety glass'. 'Safety glass' is defined as:

    England and WalesClass C according to BS 6206 or Class 3(β)φ according to EN 12600
    ScotlandClass 3(β)φ according to EN 12600
    Northern IrelandClass 3(β)φ according to EN 12600

    'Safety glass' should be CE marked to Class 3(β)φ or better everywhere in the UK. The terms(β)φ are not required to define a 'safety glass' as they relate to containment after impact.

    Additionally BS 6262 part 4 requires that: The installed safety glass should be clearly and indelibly marked with the following information;

  • the name or trade mark of the manufacturer, merchant or installer
  • the product standard that the safety glass conforms to; e.g. BS EN 12150; BS EN 14179; BS EN 14449
  • the classification according to BS EN 12600