When we talk about prevention and protection against fire, we must know how to differentiate between both terms, we can say that the term prevention in general, is part of the solutions adopted to prevent the accident from happening or limit the consequences of it, while when we talk about fire protection we bear in mind that the accident has occurred and these measures will reduce the effects produced by it, with this we can define:
- Fire Prevention: As those measures aimed at preventing the risk from being updated in an accident.
- Fire Protection: As those measures aimed at minimizing the consequences produced in case the accident is updated or occurs.
As we already know, for a fire to occur, the four elements that make up the tetrahedron of the fire must be properly combined, so the prevention measures will be aimed at eliminating some of the factors or reducing the interaction between them so that the fire occurs.
By knowing the elements that make up the tetrahedron of fire, we can see that there are elements of it on which it is more feasible to act than on others, that is, in most situations it will be easier to act on the fuel and the activation energy, than on the oxidizing “air”, in which we are practically immersed in most cases, as well as in the chain reaction that is practically inherent to fire.
Once we decide to act in the fight against fires we see that we can do it well from the sense of prevention or through fire protection, in addition to deciding between doing it actively or passively. As active fight we understand that we are going to perform an action aimed at limiting any of the elements of the tetrahedron the fire in case of talking about prevention, or directly on any of the elements of the tetrahedron of the fire once this has occurred, understanding in this case the action as active fire protection. After this we can classify both fronts of action as:
- Fire Prevention:
– Active Prevention
– Passive Prevention
- Fire Protection:
– Active Protection
– Passive Protection.
Fire prevention can be oriented from the active or passive point of view, so we can in turn classify it into several groups of action.
- Active Fire Prevention: We act on:
– Activation Energy
– Chain reaction
– Joint action (fuel-oxidizer mixture)
- Passive Fire Prevention: We act by:
When we decide to act through the processes of active Fire prevention, we will act on any of the elements of the tetrahedron of fire; by making a reminder, we can act:
Active Fire prevention
Action on fuel.
Eliminating the presence of flammable waste, keeping the work area clean and free of residues, having airtight containers.
Adapt the fuel dosage according to the needs of work, avoiding unnecessary excesses of fuel without consuming, with the consequent storage and risk.
Making maintenance plans in order to avoid leaks and potentially dangerous spills.
Dilute the concentration of the fuel to reduce its flammability range.
Store and transport fuels in the appropriate way, in watertight containers.
Cover the fuel with a non-combustible material, e.g. Intumescent paint for iron, or wood.
Ventilation of storage areas, avoiding the concentration of flammable mixtures.
Localized aspiration of fuel areas where flammable environments may occur.
Action on the oxidizer
The action on the oxidizer, being generally the air of the atmosphere will generate situations of difficult action on it, being able to consider preventive measures of action on the oxidizer, those aimed at avoiding the combustible-oxidizing contact such as the use of suitable and watertight containers, coating, maintenance, etc.
In very limited situations or atmospheres (tanks, chemical reactors, silos,…) where the fuel is manipulated, we can act on the oxidizer, through the process of inertization, we speak then of inert atmospheres, in which we have acted on the atmosphere decreasing or eliminating the presence of the fuel, by adding an inert gas, usually (CO2 or N2).
In the work of cleaning cisterns, the interior of the same is usually inertized with Nitrogen.
Action on the activation energy.
In line with the type of fuel we are facing, an activation energy will be necessary, so the preventive action to prevent the production of those foci capable of generating the necessary activation energy will be fundamental, for this we can act according to the cause that can originate it and the relevant preventive measure.
Acting on the chain reaction
To act on the chain reaction is to act on the release of free radicals produced during it, for this we must add, either physically or chemically compounds that hinder the propagation of this combustion reaction.
These elements act in the form of negative catalysts or inhibitors.
As an example we have the fireproofing of materials and the addition of antioxidants to plastics.
Joint action on fuel-oxidizing mixture
The detection of flammable atmospheres, by means of continuous checks (monitoring) allows to evaluate whether the controlled atmosphere is inside/outside the explosiveness limits, and when monitored, to adopt the necessary fire prevention measures.
These atmospheres are usually dust-air, steam-air and gas-air.
Dust-air atmospheres require analysis by means of nephelometers (an instrument that measures particles suspended in a fluid) or by sampling and analysis of concentrations in the laboratory, in the rest of the cases we will have explosive meters.
The monitoring of atmospheres, allows us to adopt preventive measures of action, being able to automate the actions according to needs (localized aspiration, ventilation, dilution of the atmosphere by means of an inert gas, etc …).
Passive Fire Prevention
We can include within the elements of passive prevention, all those elements that acting indirectly prevent us from the fire, here we would be talking about the signage, lighting and information of evacuation routes and location both personal and the exits and means of extinction existing in the environment, being acting in a preventive way to the appearance of the fire.
Active Fire Protection
We defined”fire protection as those measures aimed at minimising the consequences in the event of the accident being updated or produced”. Therefore we would be talking about all those fire protection installations that act once the fire has occurred, they are the subject of a detailed subject of study.
It is most deeply exposed in “Fire protection installations”:
- Fire Detection and Alarm Systems
- Emergency lighting
- Alarm systems
- Manual fire alarm systems
- Alarm communication systems
- Extinguishing systems
- Water extinguishing systems
- Extinguishing systems by sprayed, water mist
- Low-expansion physical foam extinguishing systems
- Dust extinguishing systems
- Extinguishing systems by gaseous extinguishing agents (CO2, Ni, Inergen…)
- Sprinkler extinguishing systems
- Smoke and heat control systems
- Temperature control.
- Control of smoke and temperature or heat
- Outdoor hydrant systems
- Fire extinguishers
- BIE’s systems
- Dry column systems
Passive Fire Protection
Passive protection is one whose mission is fulfilled without external action and consists of containing fire within a limited space preventing its spread while reducing damage in the affected area. Therefore we see that passive protection does not extinguish the fire but avoids major damage and losses, contributing to the extinction of the fire, since it isolates it from the rest of the building, confines it and maintains the structural and sectorization conditions, to allow the permanence and safety of the occupants and fire teams.
Therefore we can act through the structural Fire protection and the constructive elements that make up the building, for this we will study the following points:
- Fire Protection zoning of buildings.
- Compartmentalization of buildings.
- Structural behavior and collapse of a building.
- Structural protection of a building.
- Protection of steel structures
- Protection of concrete structures
- Protection of wooden structures
- Protection of installations galleries.
- Cable protection
- Protection of ventilation ducts
- Protection of stairs and elevator shafts
- Protection of facades
- Protection of passage holes
- Controlled ventilation by exutorios.