Fire safety

History shows that fire was recognised as a threat to great civilisations as early as 2000 years ago. The Roman Empire devised a system of corps vigilante whose sole task was to be on watch for the outbreak of fire. The Great Fire of London in 1666 became the catalyst for the modern day building codes. The fire broke out in a baker's shop and destroyed half of London. The buildings in London at that time were not fire separated and so the fire spread easily. Analysis of how the fire spread led to the creation of the first building regulations.

Fire Separation: the use of wall, that divides a storey or building, to resist the spread of fire or smoke.

Fire safety provides conditions of a building that eliminate risk of fire or spreading fire, prevents property damage.

Basic fire safety concepts:

- safe egress (exit) from the building for occupants;

- facilities for fighting fire within buildings;

- prevention of spread of fire to adjoining properties;

- access and egress for fire fighting personnel.

Fire hazards:

- High temperature;

- Radiant heat;

- Smoke as it contains carbon monoxide;

- Degrading visibility.

Fire temperature can reach 700-900 deg С that’s why neighboring rooms or buildings can be ignited even without contact with fire but through heat radiating.

For a person critical levels of those hazards are:

- temperature +70 deg C,

- radiant heat 1.26 kW/m²;

- carbon monoxide concentration 0.1%;

- visibility in the smoked area 6-12 m.

Fire fighting includes variety of substances, means and facilities.

Fire fighting substances:

- water. Advantages: available, cheap, not toxic. Disadvantages: can’t extinguish light substances, can’t be used to extinguish electric power facilities;

- foam is more effective than water replacing oxygen;

- water steam – moisturizes flammable substances and replace oxygen;

- inert gas – fades burning;

- sand – effective to extinguish oil substances, absorb heat and replace oxygen;

- covering materials – clothing, ground.

Fire fighting means are classified as:

- primary;

- fire alarm;

- fire machines;

- automatic fire fighting units.

Extinguishers types:

- chemical foam: operation time 60 sec, stream distance 6-8 m, can’t be used to extinguish electric facilities;