Fire Alarm Categories-Guide to BS5839
- Nov 28, 2024
- 5 min read
Updated: Apr 1
Businesses vary greatly, and fire alarm categories are no exception. Fire regulations mandate that any fire alarms you install must be suitable for their intended purpose. By selecting fire alarms in the appropriate category, you can ensure the safety of your staff and reduce risks to your property.
Fire alarms are classified into grades from A to F, with A being the highest and F the lowest. These grades reflect the system's quality. Most residential homes fall within the D to F range, needing a battery and sometimes a connection to the mains supply.
Businesses in grades A to C typically require fire detection and alarm systems that incorporate multiple technologies, such as heat detectors, fire alarms and sounders, and indicating equipment. Grade A systems should have a control system that complies with BS5839 Part 1 or Part 6.
Fire alarm categories explained
Fire alarm system categories and grades are different. Categories capture the level of protection that a system provides according to the recommendations of the BS5839 British Standards documents. In total there are eight categories that apply to commercial properties, split up into manual systems (where staff must physically activate the alarm), automatic systems for the protection of life, and automatic systems for the protection of property. Businesses can usually determine which category of system they need by conducting a thorough fire risk assessment. For instance, businesses with high-risk areas such as boiler rooms, machinery depots and plant rooms often require the most comprehensive Fire alarm systems.
Below we have broke down the fire alarm system categories in detail:
Category M – Manual fire alarm system
Manual fire alarm systems are the simplest form of alert systems. Employees must manually activate alarms upon detecting a fire to warn others in the building of the danger.
Typically, these systems use breakable glass units placed strategically throughout the building, triggering the alarm system across the premises.
(In some cases, manual systems still utilize handbells or gongs if the premises are small and only need a single sounder to effectively alert the entire area.)
Category L1 – Maximum life protection automated fire alarm system
L1 maximum life protection automated fire alarm systems offer the most extensive coverage, featuring multiple detectors in every area of the building where a fire might ignite, such as larger cupboards, roof spaces, and voids.
The objective is to deliver the earliest warning to occupants to ensure life preservation. The system should encompass all areas of a building, with a few minor exceptions, like small cupboards and lobbies.
Category L2 – Additional life protection automated fire alarm system
L2 alarm systems offer building occupants early notification of a fire occurring in a different room. This usually includes installing fire and smoke alarms in high-risk areas and along escape routes leading to fire exits. In small and medium-sized buildings, L2 systems position fire detectors in locations with a high risk of ignition, like kitchens.
Category L3 – Standard life protection automated fire alarm system
Category L3 fire alarm systems, often referred to as standard life protection systems, include alarms positioned along all escape routes from inside the building to the fire exits.
The aim is to provide enough warning for all occupants to evacuate the building before smoke, fire, and toxic fumes hinder their escape. In contrast to L2 systems, L3 systems are not required to install alarms near high-risk ignition sources.
Category L4 – Modest life protection automated fire alarm system
L4 systems install detectors solely along escape paths like hallways, stairwells, and related circulation areas, rather than in individual rooms. Businesses utilizing L4 systems typically function in low-risk settings where rapid evacuation is feasible during a fire.
For example, ground floor offices might only have L4 alarms in their entrances since staff can exit the building swiftly. However, these systems are inappropriate for multi-storey offices where employees might need more time to evacuate through stairwells.
Category L5 – Localised life protection automated fire alarm system
L5 category alarms are a specialized type of automated fire system designed to address fire hazards in high-risk areas.
For instance, a factory might add extra fire detection devices in a welding area due to the risk of sparks igniting a fire. Conceptually, L5 alarms differ from other systems previously mentioned. It is possible for a business to operate an L4 system throughout its premises while using L5 in specific high-risk rooms.
For example, some companies might implement fire detection equipment up to L5 standards in a server room while leaving the rest of the building as it is.
Category P1 – Maximum property protection automated fire alarm system
Category P1 systems provide the highest level of protection for property against fire. In a business setting, this often means adding extra safety measures in areas vital to operations. For instance, a utility company might implement a P1 system in a computer room where all customer data is kept.
The purpose of P1 systems is to detect fires quickly and extinguish them before they cause significant damage. By identifying fires early, they help protect lives and preserve crucial business assets. Essentially, P1 systems are part of business continuity planning, aiding in minimizing disruptions and reducing clean-up costs.
Category P2 – Minimum property protection automated fire alarm system
P1 systems install fire and smoke detectors throughout the entire premises, while P2 systems focus on high-risk areas only.
P2 systems are cost-effective solutions that utilize funds more efficiently. However, they may fail businesses if fires occur in unexpected locations.
Above, we have outlined fire alarm categories specific to business properties; there are separate categories for domestic properties, which follow a similar structure.
Category LD1 – Maximum life protection for a domestic property
LD1 alarm systems are installed throughout domestic premises. Detectors are placed in all areas that serve as escape routes and in all rooms and other areas, except those with a low risk of ignition, such as bathrooms and toilets.
The aim is to provide the earliest possible warning for occupants to ensure their safety.
Category LD2 – Additional life protection for a domestic property
LD2 fire alarm systems necessitate the installation of detectors in circulation areas that are part of escape routes, as well as in specific rooms or areas that pose a high fire risk to occupants. This includes a kitchen and a primary habitable room within the building.
Category LD3 – Standard life protection for a domestic property
Category LD3 systems include detectors in every area that serves as an escape route from the property. In contrast to LD2 systems, LD3 systems are not required to install alarms near high-risk ignition sources.
Learn more about the categories and regulations
Determining the appropriate fire alarm category for your specific location can be a complex and challenging task. Various factors must be considered, including the type of building, the occupancy levels, the specific fire hazards present, and local regulations that govern fire safety requirements. Each of these elements plays a crucial role in identifying the most suitable fire alarm system that not only meets legal standards but also ensures the safety of all occupants.
Fortunately, the Veteran Fire Safety team is readily available to consult with your business and provide expert guidance on the fire alarm systems that you should consider implementing. Our experienced professionals are well-versed in the intricacies of fire safety regulations and can help you navigate through the myriad options available. We take the time to assess your unique situation, understanding the specific needs of your facility, and recommending tailored solutions that enhance safety and compliance.
We invite you to contact us for a complimentary survey of your premises. This initial assessment allows us to evaluate your current fire safety measures and identify any potential gaps or areas for improvement. Our goal is to ensure that you are not leaving your fire safety to chance, but rather taking proactive steps to protect your employees, customers, and property. With our expertise, you can have peace of mind knowing that your fire alarm system is appropriately categorized and effectively designed to mitigate risks and respond to emergencies.
