FIRE PREVENTION MEASURES

 FIRE PREVENTION MEASURES

 AS PER NATIONAL BUILDING CODE (NBC)

NATIONAL BUILDING CODE 2016(third revision) is a comprehensive document containing rules, regulations and stipulations regarding materials, technology, design and construction, it provides the necessary fire safety and construction safety management guidelines for regulating necessary building construction activities across the country.

The 2016 document contains 12 Parts which are further divided into different Sections totalling 33 chapters. PART 4(IV) (FIRE AND LIFE SAFETY) specifically deals with safety from fire.  It specifies the 

·      Classification of buildings based on occupancy,

·      Demarcation of fire zones

·      Restrictions on the construction of buildings in each fire zone

·      Types of building construction according to the fire resistance of components

·      Requirements to be met to minimize danger to life from fire, smoke, fumes or panic before the buildings can be evacuated.

 

Part 4 (FIRE AND LIFE SAFETY) is divided into three broad clauses

1. FIRE PREVENTION:  This section covers the aspects related to the passive fire protection measures to be incorporated while design and construction and various types of building materials to be used based on their fire rating 
2. LIFE SAFETY: This section covers the aspects related to safety provisions to be created to deal with emergencies like fire and addresses occupancy and construction features to be taken up during construction to minimize danger to life from smoke, fire, fumes or panic.
3. FIRE PROTECTION: This section provides guidelines for the correct selection of equipment and installation meant for fire protection depending upon the type of building.

 

FIRE PREVENTION 

CLASSIFICATION OF BUILDING BASED ON OCCUPANCY

All buildings, whether existing or hereafter erected shall be classified according to use or the character of occupancy in one of the following groups along with “Minor occupancy” and “Mixed occupancy” where the occupancy is treated under the relevant groups

  

MAIN GROUP	TYPE OF OCCUPANCY	SUB GROUPS
GROUP A	RESIDENTIAL	There are 6 sub-groups in Residential occupancy (A1- A6)
GROUP B	EDUCATIONAL	There are 2  sub-groups (B1- B2 )
GROUP C	INSTITUTIONAL	There are 3 sub-groups (C1- C3)
GROUP D	ASSEMBLY	There are 7 sub-groups (D1-D7)
GROUP E	BUSINESS	There are 5 sub-groups (E1- E5)
GROUP F	MERCANTILE	There are 3 sub-groups (F1 - F3)
GROUP G	INDUSTRIAL	There are 3 sub-groups (G1-G3)
GROUP H	STORAGE
GROUP J	HAZARDOUS

 

CLASSIFICATION OF OCCUPANCIES INTO FIRE ZONES:

Based on fire hazard inherent in the buildings and structures according to occupancy, they are divided into THREE (3) distinct fire zones 

 

FIRE ZONE	OCCUPANCIES THAT COME UNDER THESE FIRE ZONES
FIRE ZONE – 1	A, B, C, D, E-1 AND F
FIRE ZONE – 2	E2- E5, AND G
FIRE ZONE – 3	H AND J

 

 

CLASSIFICATION OF BUILDINGS BASED ON TYPES OF CONSTRUCTION

 The types of construction according to FIRE RESISTANCE (The fire resistance of a building or its structural and non-structural elements is expressed in minutes against a specified fire load which is expressed in kcal/m2, and against a certain intensity of fire) shall be classified into four categories.

  

1. Type 1 Construction, 
2. Type 2 Construction,
3. Type 3 Construction 
4. Type 4 Construction. 

  

GENERAL FIRE SAFETY REQUIREMENTS COMMON TO ALL OCCUPANCIES

FIRE COMMAND CENTRE: The fire command centre should be at the entrance of the building and should be constructed with 120 min fire rating with emergency lighting and all controls and monitoring of fire alarm systems, pressurization systems, smoke management systems should be done from this room

SURFACE FINISHES:  These affects the safety of the occupants depending upon the type of material used as a surface finish for walls, ceilings etc, they may spread the fire faster, hence based on the susceptibility of types of wall surfaces, surfacing material is classified into 4 classes

·      CLASS  - I  Surfaces – they have a very low flame spread

·      CLASS – 2 Surfaces -  they have a low flame spread

·      CLASS – 3 Surfaces – they have a medium flame spread

·      CLASS – 4 Surfaces – they have a rapid flame spread      

 

Class 4 materials like wood fibre board’s which have high flame spread should not be used in kitchen, corridors and staircases

 

EXIT SIGNAGES:  Exit signs to be provided such that no point in exit access is more than 30 meter from a visible exit directional sign. Whenever there is a change in the direction an exit sign indicating the direction to that particular exit to be provided. 

Exit signs to be illuminated and wired to independent electrical alternate supply and the exits shall be visible and the route to reach the exits shall be clearly marked and signs posted to guide the occupants. The exit sign is an arrow indicating the escape route provided at a suitable height to have a proper view for all occupants. The colour of the exit signs should be green 

 

LIGHTING:   Escape lighting should help occupants to

1)     Clearly identify the escape route

2)    Provide required illumination to help occupants to move towards and through the exits without any hindrance

3)    Fire call points and firefighting equipment are provided along the escape route 

The emergency lighting to get switch on within 5 seconds of the failure of the normal lighting supply. And should provide illumination level for not less than 90 min 

EMERGENCY POWER:  Emergency power is critical for the functioning of fire and life safety system and reliable source of power should support the below systems

·      Fire pumps

·      All lifts 

·      Exit signage lighting

·      Emergency lighting

·      Fire alarm system

·      Public address (PA) system

·      Magnetic door hold-open devices

·      Lighting in the fire command centre and security room.

·      Pressurization and smoke venting

 

 

ELECTRICAL INSTALLATIONS:  It has to ensure that low and medium voltage wiring running in shafts and false ceiling should be in metal conduit and 230 v wiring above the false ceiling to be of 660 V grade insulation.

 

Water mains, gas pipes, telephone lines, intercom lines or any other service line not to  be laid in the duct for electrical cables and all metallic items shall be bonded properly to the earthing system              

 

OTHER INSTALLATIONS: Air conditioning, ventilating systems should be installed and maintained to minimize the danger of the spread of fire, smoke or fumes from one floor to other or from outside to any occupied building or structure. 

 

Separate air handling units (AHU) for each floor shall be provided to avoid the hazards arising from the spread of fire and smoke through the air conditioning ducts. 

 

It has to be ensured that Air ducts should not pass through the exits/exit passageway/ exit enclosure

HSE Notes by PJ Mohan

Sr.Faculty, NIFS