Categories of
Fire Alarm Systems

There are two main categories of fire alarm systems; protection of life and property. Which one is best for you?

Fire safety is of utmost importance in any commercial building. To ensure the safety of occupants and minimise property damage, fire alarm systems play a crucial role. These systems can be broadly categorised into two main categories: those designed to protect life and those intended to protect property. Understanding the different categories and their specifications can help you determine which fire alarm system is best suited for your specific needs.

Understanding Categories of Fire Alarm Systems

In existing commercial buildings, compliance with the Regulatory Reform (Fire Safety) Order 2005 is mandatory. This order places the responsibility on the designated “Responsible Person” within an organisation to conduct a comprehensive fire risk assessment of the premises. The assessment evaluates the fire risk in the building, assesses the adequacy of existing fire precautions, and determines the need for additional safety measures. The results of the fire risk assessment guide the selection of an appropriate fire alarm system for your business premises.

The British Standard BS 5839-1:2017 provides a code of practice for the design, installation, commissioning, and maintenance of fire detection and alarm systems in non-domestic buildings. This standard introduces the concept of “Categories,” which define the objectives that a fire alarm system should fulfil. The two primary categories are those focused on protecting life (Categories L and M) and those dedicated to property protection (Category P). It is common for fire alarm systems in a building to incorporate a combination of these Categories to cater to different requirements.

Life protection

Life Protection systems focus on safeguarding individuals within a building. The category ranges from Type L1 to simple M systems, depending on the number of occupants and specific variations.

Category l

Category L systems are automatic fire detection and alarm systems with the aim of protecting life. There are 5 levels within this category, each offering a different level of fire protection.

Category L1 Fire Alarm Systems

Category L1 fire alarm systems offer the highest level of life protection. They recommend the installation of both manual call points (MCPs) and automatic fire detection (AFD) throughout the entire premises, including roof spaces and voids. The objective is to provide the earliest possible warning in the event of a fire. Certain low-fire-risk areas, such as stairways, lobbies, and small cupboards, may be exempt from protection.

Category L1 systems are typically found in residential care premises and large office blocks.

L1 Fire Alarm System

Category L2 Fire Alarm Systems

Category L2 fire alarm systems enhance the level of protection provided by Category L3 systems. They include additional detection in areas with a high risk of ignition, identified through a fire risk assessment. Automatic detectors are installed in escape routes, rooms adjoining escape routes, and high-hazard rooms like kitchens, boiler rooms, and plant rooms.

The system aims to provide occupants with sufficient time to evacuate before escape routes become impassable due to smoke and flames.

Category L2 systems are suitable for medium-sized premises accommodating up to ten residents.

L2 Fire Alarm System

Category L3 Fire Alarm Systems

Category L3 fire alarm systems incorporate manual call points (MCPs) at defined positions and automatic fire detection (AFD) in all escape routes, rooms, corridors, and compartments that open onto escape routes. The objective is to provide early warning to occupants beyond the room in which the fire originates, allowing them to utilise escape routes before they become filled with smoke.

Category L3 systems offer broader coverage compared to Category L4.

L3 Fire Alarm System

Category L4 Fire Alarm Systems

Category L4 fire alarm systems feature manual call points (MCPs) placed throughout the building, along with automatic fire detection (AFD) along escape routes, including stairwells. The purpose is to alert people to the danger before corridors become smoke-filled, enabling safe evacuation.

While Category L4 provides detection within escape routes, Category L3 covers not only these areas but also all rooms leading to the escape route.

It is important to note that a Category L4 system does not meet the legislative requirements for buildings accommodating sleeping individuals.

L4 Fire Alarm System

Category L5 Fire Alarm Systems

Category L5 systems are designed to meet specialised fire safety objectives, deviating from the standard recommendations where strict adherence may not be feasible. These systems could include automatically closing metal shutters on shopfronts to contain the fire or computer rooms equipped with an extinguishing system triggered by automatic detection.

The decision to implement a Category L5 system is typically based on recommendations from a fire risk assessment (FRA) and is tailored to address specific risks and client requirements.

L5 Fire Alarm System

Category m

Category M fire alarm systems are primarily focused on places of employment without sleeping risks. These systems rely on manual call points (MCPs) installed on all exits and corridors where individuals are not expected to walk more than 30/45 meters to operate them.

There is no automatic detection in Category M systems, as they depend on the occupants to discover the fire and activate the system. Category M systems are commonly found in workshops or factories.

M Fire Alarm System

property protection

Category P systems aim to provide the earliest possible fire detection, minimising the time between ignition and the arrival of the fire services. The goal is to reduce property damage.

category p

These types of systems are purely for the protection of property and fall into two classifications, Category P1 and Category P2.

Category P1 is designed to protect the whole building, Category P2 is installed in defined parts of the building only, which may have a high risk or hazard.

Category P1 Fire Alarm Systems

Category P1 fire alarm systems focus on protecting the entire building and providing the earliest possible fire warning. Detectors and alarms should be strategically placed in all areas of the building to promptly alert the fire and rescue service upon the outbreak of a fire, thereby minimising property damage.

Conducting a fire risk assessment is crucial in designing Category P1 systems, as it helps identify specific risks present in each room and determines the appropriate detectors.

P1 Fire Alarm System

Category P1/M Fire Alarm Systems

The inclusion of “/M” in Category P1/M systems indicates that a full Category M system should be combined with a full Category P1 system. This means that automatic fire detection (AFD), manual call points (MCPs), and alarm devices should be installed throughout the entire building.

Category P2 Fire Alarm Systems

Category P2 fire alarm systems provide fire detection in specific parts of the building where focused coverage may be required. These areas typically entail a higher risk or hazard, or there is a need to minimise business disruption and protect valuable content.

P2 Fire Alarm System

Category P2/M Fire Alarm Systems

Similar to Category P1/M systems, Category P2/M systems require the integration of a full Category M system with a full Category P2 system. AFD, MCPs, and alarm devices should be installed throughout the entire building.

Choosing the Right Fire Alarm System for You

When selecting the most appropriate fire alarm system for your needs, it is crucial to consider factors such as the size of the building, the number of occupants, the level of fire risk, and any specific requirements identified through a fire risk assessment. Consulting with fire safety experts and professionals can provide valuable guidance in making an informed decision.

Choosing the right fire alarm system is crucial for ensuring the safety of occupants and protecting valuable property. Familiarising yourself with the different categories of fire alarm systems and their specific features empowers you to make an informed decision based on your unique requirements. By conducting a thorough fire risk assessment and seeking advice from professionals in the field, you can ensure that your chosen fire alarm system provides optimal protection in the event of a fire.

Fire Risk Consultancy Services have the knowledge and experience to assist your business to comply with all legal requirements surrounding Fire Safety including the legislation regarding Fire Alarms. Be sure to read our accompanying guides: British Standards Relating to Relating to Fire Alarms,  A Guide to Fire Alarm System Types, Different Types of Fire Detector Heads, Fire Alarms in the Home, AND Fire Extinguishers, Emergency Lighting, Fire Door Regulations, Fire Safety Signs, also published on this site. 

Please take a moment to have a look around our website where you will find related articles and guides to all the services we can provide your business with, from providing fire risk assessments, fire safety training, advisory services to Articles on Fire Safety Provisions and our Top Fire Safety Tips!