Precautions :

The designer, or specifier, should take precautions to reduce the risk of injuries from accidental human impact in these locations by :

(a) Selecting glass of a suitable type, thickness and size, primarily with reference to impact behavior and safety characteristics as established by testing in accordance with this guide.

(b) Providing mechanical protection to glass in critical locations, to prevent fall of glass under impact.

(c) Enhancing a person’s awareness of the presence of glass by incorporating manifestation. (explained in para ‘manifestation’ below).

Glass in locations other than critical locations is not likely to be subject to human impact and consequently not likely to cause injury.

Design Consideration :

The principal design considerations to be taken into account by the designer, or specifier, when selecting glass should be :
(a) The properties of materials, in particular their breakage characteristics.
(b) Structural integrity of glazing systems supporting the glass.
(c) The type of the building and its use, in particular the number and likely behavior of the people expected to be in close proximity to the glass in critical locations.
(d) Requirements for fire, security and wind loading.
(e) Thermal breakage, energy efficiency and deflection, vision, acoustics and other consideration.
(f) Impact of trolleys, carts, luggage etc. used have to be considered when required.

Manifestation :

Clear glass panels capable of being mistaken for an unimpeded path of travel should be marked to make them visible by incorporating manifestation. Manifestation employed shall be in form of opaque band of size not less than 20 mm in height and located at vertical distance from floor level to not less than 700 mm from upper edge of band and not more than 1200 mm to lower edge of the band.

The manifestation shall preferably be permanent, e.g. etching of the glazing, but alternatively, if applied materials are used they shall be durable and not easily removed.

Notes :

Note 1: The effective Toughened safety glass thickness and/or Laminated safety glass configuration shall be determined case by case with regard to:

1. Other solicitation (wind load, snow load, dead load and human load)

2. The overall dimensions (length / width, or surface)

3. The aspect ratio of the glass length / width)

4. The glazing fixing type (framing, bolted system, structural system etc.) (AS : 1288-2006)

Note 2 :

Precautions against chances of injuries due to broken glass falling on people:
(a) Broken annealed glass falling on people can cause grievous or even fatal injuries; hence it is recommended to use safety glass in locations other than defined in case1 where the risk of people getting hurt by falling glass is high.

(b) Toughened (tempered) glass has a safe breakage pattern, as it breaks and disintegrates into small and relatively harmless particles. However thick toughened glass particles may stay interlocked and fall as lumps of these multiple particles and can cause a minor or medium injury mainly due to the weight of the cluster.

(c) Laminated safety glass will generally not fall out of fixing. However, where laminated glass with both glasses toughened, used for horizontal or sloped glazing is used, in case of failure of both toughened glasses, it may crumple as a wet blanket and fall out of fixing. This factor needs to be considered while designing horizontal and sloped glazing.

(d) Any broken glass in any glazing should be removed immediately on breakage.

(e) Strength of the glazing system should be such that it has the ability to hold glass in place and prevent it from falling out as a whole. This is particularly important for security glasses.

Note 3 : If Insulating Glass Unit (IGU) is used in situations mentioned in this guide then any one of the following will apply:

(i) If IGU is installed in areas subjected to human impact on either side, then both the panes of the unit shall meet the requirements of this guide.

(ii) In situations where access is restricted to one side of the unit, then only the accessible side should meet the requirements of this guide.

Note 4 : For inclusion of glass in furniture’s the following standards the following standards may be referred :

(a) BS 7499:1991 : Specification for inclusion of glass in the construction of furniture, other than tables or trolleys, including cabinets, shelving systems and wall hung or free standing mirrors.

(b) BS 7376:1990 : Specification for inclusion of glass in the construction of tables or trolleys.

(c) IS 7760:1985 : Specification for steel glass-front cabinet.

(d) BS EN 1727:1998 : Domestic furniture, storage furniture, safety requirements and test methods.

(e) BS EN 1153:1996 : Kitchen furniture, safety requirements and test methods for built-in and free standing
kitchen cabinets and work tops.

Building design and Fire Safety :

Indian cities are changing rapidly due to the construction boom. A major part of the construction is happening in buildings where high amount of human traffic is expected to happen like malls, commercial complexes, high rise buildings, IT parks etc. Due to the high quantum of human traffic these kinds of buildings have special needs for human safety and security.

This is addressed by the utilization of modern building design methods as well as usage of new-age building materials. One of the key aspects of safety in building design that is gaining priority is protecting occupants against fire hazards.

In the event of a fire, the area engulfed by the fire is very hostile and its effects can be catastrophic to life and property. The occurrence and dispersal of fire is extremely unpredictable and uncertain. It is therefore critical that appropriate and tested products are chosen.

It is generally thought that fire safety regulations impose a uniform criterion on design. This is far from the truth. The unique qualities and performance range of modern fire rated glass systems encourages freedom and flexibility of design, while satisfying almost all necessary fire safety and protection requirements.

Passive protection Vs Active protection :

Most organizations spend huge amounts of money on active fire control systems like sprinklers, fire extinguishers, foamers etc. However statistics say that 40% of the active controls fail or are subject to a delayed start due to various reasons. It is at these times that passive fire protection systems provide for the much-required additional time for enabling quick action for saving life and property.

Fire proof glass panels or complete glass screens are often required to allow vision and natural light through fire-rated internal walls and doors. Indeed, fire resistant glazing can provide an important safety benefit – other building occupants can be seen on the other side of the door, as can hazards such as smoke in the case of a fire.

The modern solutions for fire safety glass :
Internationally today, there are excellent alternatives available for clear vision safety glass. These include high performance products like transparent glasses with intumescent layers, special coatings and laminates. These products also have better performances. They have also opened up new avenues for architectural creativity, as they are transparent products, look aesthetically appealing and integrate well with the other glass products used in the interiors. These solutions are safe, impact resistant and provide
clear vision fireproof glazing that has test evidences of satisfying functional and time requirements for fireproofing.

In fact today there are products that can actually substitute a brick wall in terms of fire rating property yet give transparency. While some of the fire safety glasses function as a physical barrier preventing spread of fire and smoke, certain advanced solutions can actually drastically cut off the radiant heat from a fire.

Typically radiant heat from an electrical fire can reach as high as 40 KW in 30 to 60 minutes. Combustible objects like wood can auto ignite at around 10 KW of heat. 5 KW is the limit of bearable human pain. The modern fire safety glass solutions help to cut off the radiant heat apart from providing safety.

Choosing Fire resistant glazing :

When we talk of fire, we have to factor in the radiant heat that a fire generates. Radiant heat is invisible, extremely intense electromagnetic waves that travel at the speed of light. On striking an object these waves are absorbed and their energy is converted into heat. Combustible objects like paper and wood auto ignite due to the heat when they reach their flash point. While deciding on the ideal fire rated glazing product, it is important to decide what the design and safety needs are. We need to decide whether glazing requirement comes with only integrity or insulation or radiation control. Simultaneously we need to decide as to for what duration we need the fire resistance and whether the fire protection capability needs are from one side of the glazing (as in case of fire escape passages), or from both sides (as in case of internal partition between two sections in an office).

In terms of functional requirement, we have three broad ranges of international classifications each of these can be as per specific time requirements also.

E = Integrity : Glass that stops the spread of fire and smoke from the fire side to the non fire side
EW = Integrity and Radiation Control : Glass that stops the spread of fire and smoke from the fire side to the non fire side and also gives partial heat reduction < upto < 15 KW at 1 mtr distance
EI = Integrity and Insulation : Glass that stops the spread of fire and smoke from the fire side to the non fire side and also gives very high heat insulation.

In case of external laminated glass facades, openable portions have to be left at regular distances for fire fighting and smoke exhaust.