Fire Alarm System Categories
The eight categories of fire alarm systems include:
Each category falls under three different types of systems – manual, life protection and property protection. The category of fire alarm system your business requires will depend on:
Your type of premises
The contents within your business
The nature of your business
The level of risk
Manual fire alarm systems
These are the least sophisticated of systems, which rely on the building’s occupants to detect a fire and provide a warning to others. When a fire is discovered, employees must activate the alarm manually, in order to alert everybody else in the building to the danger.
A typical example of a manual fire alarm system is a series of break glass units, which are installed at each point of exit in a building. This allows those escaping a fire to raise the alarm as they leave the danger zone.
Automatic fire alarm systems for the protection of life
Fire alarm systems that fall into the L category are those deemed most suitable for protecting life within a building. Systems designed for this purpose are divided into five sub-categories, depending on their level of effectiveness.
Category L1 – Maximum life protection
This is the most comprehensive fire alarm system, which features detectors in all areas of a building where a fire could feasibly start. Detectors are linked up to a centralised alarm system. This alerts the whole building should a fire break out.
The objective of this setup is to ensure that inhabitants are given the earliest possible warning, should an emergency occur. It is therefore the ideal standard for premises such as large hotels and care homes, where early detection of a fire is crucial to the chances of escape.
Category L2 – Additional life protection
Fire alarm systems that fall into this category feature smoke detectors in all rooms that form part of an escape route, including corridors. Detectors also need to be installed in all high-risk rooms, such as kitchens, boiler rooms and areas with heavy plant machinery.
L2 systems are effective at providing an early warning to occupants beyond the source of the fire and those working in high risk areas. Examples of properties that typically employ this system include factories or medium sized residential premises.
Category L3 – Standard life protection
Standard life protection systems feature detectors in all escape routes and rooms that open onto an escape route. The objective of this system is to ensure that all inhabitants of the building are given enough warning to escape a fire, before their exit is impeded by the presence of flames, smoke or toxic fumes.
This category of fire alarm system is typically adopted in regular sized office blocks and commercial buildings that have flights of stairs
Category L4 – Modest life protection
An L4 category fire alarm system consists of detectors within escape route areas only, such as in corridors and stairways. Any circulation areas which make up part of the escape passage should also be fitted with a detector.
Commercial properties that generally adopt this category of system are those having a lower level of risk. For example, an office that consists of ground floor rooms only would require less warning time to evacuate all personnel.
Category L5 – Localised life protection
L5 fire alarm systems are those that are installed to tackle a specific fire risk in a certain area of a building. For example, if there is a room in a building that poses an exceptional hazard because of the items stored there or business activities carried out there.
An L4 category system may be appropriate for the building in general but an L5 system is also required, in order to recognise the level of risk this particular room presents.
Automatic fire alarm systems for the protection of property
P category fire alarm systems are those that are designed to protect property. It is appropriate to label a system under this category, when considering how a business and its operations will be protected from the risk of fire.
A P1 fire alarm system involves installing detectors in all areas of the building. The objective of a system like this is to protect buildings that are critical to the operations of a business.
By implementing maximum protection across a whole site, those in charge of fire safety can ensure that any fire that breaks out is detected and neutralised as quickly as possible. This lowers the risk of damage and disruption and in turn, the financial impact that a fire could inflict on a company.
In a category P2 fire alarm system, fire detectors are installed in high risk areas only. Whilst a system like this does not provide the same level of cover as a P1 solution, it does provide early detection for the most likely sources of a fire.
This early detection will decrease the time it takes for the fire services to arrive on the scene and will help to minimise any damage to the property and losses to the business.
About BS 5839 and the Regulatory Reform (Fire Safety) Order 2005
The British Standard of fire alarms (BS 5839) is part of the overarching RRO Fire Safety Order, which is legislation created to provide a fire safety standard for commercial properties. You can find out more about the Regulatory Reform (Fire Safety) Order 2005 with our handy guide.
Types of fire alarms
There are a wide range of alarms and detectors available for your business, which you can browse on our fire alarm page. In order to establish the category of system required and devices most suitable to your premises, our expert fire safety team recommend a full fire risk assessment is carried out on your site.
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