Safety and Security Glass Classification Standards

05.04.2022

 

Glass functions 

Some functions are expected form glass are as follows: 

  • daylight comfort 
  • thermal insulation,
  • UV (ultraviolet radiation) protection
  • Solar control 
  • sound insulation
  • privacy
  • security 
  • safety 
  • Decorative: design or patterned glass,
  • self-cleaning.

user needs in terms of protection for a wide range of applications:

  • Injury and risk of falling
  • Burglary and vandalism
  • Firearms and explosion

Glass applications in building

gives different level of protection in terms of safety and security for a wide range of applications :

  • Windows, roof windows, bay and door windows
  • Conservatories, roof/sloping glazing
  • Overheads, balustrades and guardrails
  • Glazed facades, skylights, spandrels

Meaning of“Safety” and “Security” 

Although Safety and Security are closely linked topics, it is important to understand the distinction between the two terms, to ensure the right glass is specified.

The term “Safety” is related to the protection from accidental damage. It is applied to glazing used to reduce the risk of accident by impact, fracture, shattering, or in a fire. 

The term “Security” is applied to glazing, which in addition to “Safety”, is able to withstand a variety of deliberate attacks
such as manual, ballistic or blast.

Since the glass can behave differently in different framing systems, it is imperative to combine high performance glazing with high performance framing systems to achieve the level of protection required.

Laminated glass

A laminated glass comprises two or more sheets of glass bonded together with two or more layers of a plastic film called PVB.

With laminated glasses, different levels of safety and security can be obtained by varying the number and/or thickness of each of the components.

If the glass breaks, the fragments of glass remain bonded to the plastic foil. This safety feature, which is often mandatory by local regulations (for example in public buildings, schools..), is also ideal for residential buildings, where it protects the occupants from injury.

Additionally laminated glass also prevents the body or the object from passing through the glass and minimizing the risk of fragments falling into the space below.

Laminated glass, installed in an appropriate frame, can be an important deterrent to ensure the security of property and occupants in a building or a home, thus reducing risk of burglary or impact of vandalism.

https://uk.saint-gobain-building-glass.com/en-gb/sgg-stadip-protect 

Thoughned glass 

Toughened glass is manufactured by subjecting the finished glass size to a heating and cooling treatment which set up high compressive stresses at the surface, and balancing tensile stresses in the centre of the glass, which increases its strength. The result is a glass that is 5 times stronger than ordinary glass of the same thickness.

When broken, toughened glass shatters into small, blunt-edged fragments, reducing the risk of personal injury. 

Heat strengthened glass is produced by a similar process to toughened glass, however, the strength developed is about half that of toughened glass. It does not meet the safe break criteria for safety glass because its breakage pattern resembles that of annealed glass. It is used to provide glass that is resistant to thermal stress and for laminating where
greater glass strength is required. 

Classifications 

the classification standards 

  • British Standard BS 6206 (Superseded by BS EN 12600)
  • Europen Standard: BS EN 12600: Pendulum Test – Impact test method and classification for flat glass
  • Europen Standard: BS EN 356: Security glazing – Testing and classification of resistance against manual attack 
  • Europen Standard BS EN 1063: Security glazing – Testing and classification of resistance against bullet attack

 

BS EN 356 Glass in building: – Security glazing – Testing and classification of resistance against manual attack 

This European Standard specifies requirements and test methods for security glazing designed to resist actions of force by delaying access of objects and/or persons to a protected space for a short period of time.

The Standard classifies security glazing products into categories of resistance to actions of force.

This specifies the requirements and test methods for glass designed to be resistant to manual attack. 

The glass is subjected to impact from a steel ball with a mass of 4.11 kg for classes P1A to P5A and an axe for classes P6B to P8B.

The test is done in two different methods: 

  1. Hard body drop test: with a 4.11 kg steel sphere (100mm diameter): 
  2. Axe test: Impact from hammer followed by axe, 

 

The classes of resistance are summarised below in the following Table: 

Hard body drop test (The Lower Resistance Level)

This level represents a manual attack using a blunt instrument such as a hammer.
The test comprises dropping a 100mm steel ball (4.11kg) from various heights.

Ball weight: 4.11 kg steel sphere (100mm diameter)
Requirement: To pass test, the ball must not penetrate the glass

Class of resistance Drop height (m)Number of strikes

Impact Energy

(Joules)

P1A1.5m3 drops in a triangle 181
P2A3m3 drops in a triangle 362
P3A6m3 drops in a triangle 724
P4A9m3 drops in a triangle 1086
P5A9m9 drops in a triangle 3258

 

Axe test (The Higher Resistance Level)

Impact from hammer followed by axe
Minimum number of strikes to create opening

This level represents a more sustained assault with Hammer and Axe blows.
The test comprises; A hydraulically driven hammer head 40mm square weighing 2kg, initially being used to destroy the glass face with a min of 12 blows. A 2kg axe head hitting the same sample a min 12 blows with the intention of cutting a 400mm square hole.

Class of resistance  Number of strikes

Code designation of resistance class 

BS EN 356

P6BAxe strikes on broken glassFrom 30 to 50BS EN 356 P6B
P7BAxe strikes on broken glassFrom 51 to 70BS EN 356 P7B
P8BAxe strikes on broken glassMore than 70BS EN 356 P8B