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British Standards Fire Alarm

British Standards are the official standards for a variety of sectors in the UK, including fire safety. They ensure quality and consistency across the materials, manufacturing, maintenance, and use, and facilitate confidence in the end-users.

Though they are not a legal requirement, the products that do not comply with the standards can be deemed unfit for use and even dangerous.

There have been several cases over the years where products not complying with standards resulted in severe damages, accidents, and even death.

With something so important as fire safety, you need to make sure that the fire alarms you install on your property all comply with the standards so that you can be sure about their efficiency and reliability.

Read on to find out more about British Standard fire alarms, what is involved in the standards, the BSI symbol, and what the standards say about servicing and maintenance:


Whether you are looking to increase fire safety through the installation of fire alarms in your domestic, commercial, or public property, you need to make sure that they comply with the relevant fire safety standards and are an effective fire detection method.

If you are a homeowner, it is your responsibility to install adequate fire detection systems in the form of fully functional smoke alarms throughout the property. In the case of a commercial or public property, there are strict standards, controls, and regulations to keep in mind.

BS 5839 are the standards pertaining to fire alarms that help make products safer and more reliable. They reduce risk, increase sustainability, promote innovation, and ensure better quality.

British standard fire alarms all have a BSI (British Standards Institution) Kitemark™, which is the quality mark owned and operated by BSI and recognised throughout the world as a quality symbol. It confirms that the product in question conforms to a set standard and sets it apart from the rest.


BS 5839 are the code of practice for designing, installing, commissioning, and maintaining fire alarm systems in non-domestic buildings and they contain important recommendations for where the systems should be located based on what you wish to use them for.

There are 8 categories in total that are divided into manual systems (where someone must physically activate the alarm), automatic systems for life protection, and automatic systems for property protection.

The best way to determine which fire alarm category you need is through a fire risk assessment, which is a legal requirement under The Regulatory Reform (Fire Safety) Order 2005.

In carrying out the assessment, a responsible person must:

  • Identify the hazards,
  • Identify the people at risk,
  • Evaluate and either remove or reduce the risk,
  • Record the findings, prepare an emergency plan, and provide training for the smooth execution of the plan,
  • Regularly review and update the fire risk assessment.

Businesses with high-risk environments and operations will often require comprehensive fire alarm systems for maximum protection.

It is also very common to see a mix of fire alarm systems belonging to different categories being installed in one building.


There are two main categories of British Standards fire alarm systems: life protection and property protection. Let’s look at each in detail:


Life protection fire alarm systems, as the name suggests, focus mainly on protecting life and will often depend on the number of people accessing the building. There are several types of systems in the life protection category, ranging from Type L1 to simple M categories.


Category L systems are automatic fire alarm systems with the main purpose of protecting life. There are 5 levels in this category with each offering a different level of protection.

Category L1

Category L1 fire alarm systems provide the most life protection as they recommend installing both manual call points as well as automatic fire detection throughout the property in order to provide the earliest possible warning.

Some areas may be left unprotected if they are low-risk such as stairways and lobbies. Typical installations include large office blocks and residential care premises.

Category L2

Category L2 fire alarm systems provide enhanced protection than Category L3 systems with additional detectors in high-risk areas identified through a fire risk assessment.

These systems have automatic detectors installed in areas such as the escape routes, kitchens, and boiler rooms, and are designed to allow occupants to safely evacuate before the escape routes get affected by smoke and flames.

Category L3

Category L3 fire alarm systems include manual call points at certain locations and automatic fire detection in escape routes, corridors, and areas that open into the escape routes.

They provide a more extensive cover than L4 systems and are designed to alert the occupants beyond the area where the fire started to allow them to use the escape routes before they are filled with smoke.

Category L4

Category L4 fire alarm systems have manual call points installed throughout the premises and automatic fire detection installed along the escape routes, including the stairs.

Their main purpose is to alert the occupants of the danger before the escape routes become unpassable. They provide detection only within the escape routes whereas category L3 systems cover the escape routes as well as the room leading to them.

Category L5

Category L5 fire alarm systems are for meeting specific fire safety objectives, mostly where strict adherence would not be possible.

Such systems, for example, may include automatically closing metal shutters to contain the fire to a certain area that may be protected with a fire suppressant system triggered by automatic detection.

The requirement for such systems is often based on the findings of a fire risk assessment and must be provided as part of the fire system specification. This is a special custom category that relates to a particular risk that warrants special attention.


Category M fire alarm systems use manual call points installed on every exit as well as every corridor where people are not expected to walk more than 30 or 45 metres to operate one.

They do not use automatic detection and rely instead on the occupants of the building to activate the system in the event of a fire discovery.


Property protection fire alarm systems, as the name suggests, provide the earliest warning in the event of a fire to minimise the time it takes from the ignition of fire to controlling and extinguishing it in order to minimise loss to property.


Category P fire alarm systems are designed to protect property and fall into two classifications – P1 and P2 – where P1 is used to protect the whole building and P2 is installed only in certain high-risk areas.

Category P1

Category P1 fire alarm systems offer the earliest possible fire warning and are designed to protect the entirety of the building.

Detectors and alarms are placed in all areas of the building so that it can be detected as soon as a fire breaks out and the fire and rescue services can be alerted to minimise property damage.

A fire risk assessment is extremely helpful in designing category P1 systems as it will help determine the high-risk locations where the appropriate detectors need to be placed.

Category P1/M

The addition of M with P1 indicates that a full category M fire alarm system must be installed with a full category P1 system. These systems are made of automatic fire detection, manual call points, and alarm devices installed throughout the building.

Category P2

Category P2 fire alarm systems offer fire detection in certain high-risk areas of the building where more coverage may be needed. Examples of prime locations include areas where business disruption must be minimised or where the contents are particularly valuable.

Category P2/M

Similar to P1/M fire alarms, Category P2/M fire alarm systems indicate a full category M system linked to a full category P2 system. This includes automatic fire detection, manual call points, as well as alarm devices installed throughout the building.


There are six grades of fire alarms according to the BS 5839-6:2019 that detail the kind of equipment used in the system.

  • Grade A:Separate detectors and sounders with back-up power supply and central control equipment that conform to British Standards BS EN 54.
  • Grade C:Separate detectors, sounders, and central control equipment connected to a common power supply, comprising the mains and standby supply.
  • Grade D1:One or more detectors, powered by the mains supply along with a tamper-proof standby supply consisting of a battery or batteries.
  • Grade D2:One or more detectors, powered by the mains supply along with a standby supply consisting of a replaceable battery or batteries.
  • Grade F1:One or more detectors powered by a tamper-proof, replaceable primary battery or batteries.
  • Grade F2:One or more detectors powered by a replaceable primary battery or batteries.


Regardless of how high-quality and technologically advanced your fire alarm systems are, there will always be the need for proper servicing and maintenance in order to ensure continuous reliability, efficiency, and performance.

Since a fire detection system is designed to protect life and/or property, it is vital to conduct maintenance, inspection, and testing on a regular basis.

It is a detailed process that can involve several individuals, but the Standards recommend a single “responsible person” to supervise all matters pertaining to the fire alarm system whose role would be to ensure that it is properly maintained and tested in accordance with the British Standards.

There are three main reasons it is so important to routinely maintain and test your fire alarms:

  1. To identify any faults and issues and take appropriate action to rectify them.
  2. To ensure there have been no major failures.
  3. To familiarise the occupants with the fire alarm system.

To reach the above-mentioned objectives, it is essential for property owners to establish a schedule for testing, which can be divided into weekly and monthly routines.


According to the British Standards, there are five recommendations with respect to the weekly testing conducted by the users:

  1. The operation of a manual call point during regular working hours;
  2. Carrying out the test at approximately the same time every week;
  3. Additional tests carried out at least once a month for any occupants not usually present during the weekly tests;
  4. In systems with several manual call points, a different one to be tested every week in order to cover all the systems over a period of time;
  5. Not exceeding the routine test over a minute so that the occupants can easily distinguish between weekly alarms and an actual fire alarm.


According to the British Standards, there are two recommendations with respect to the monthly testing conducted by the users:

  1. If the standby power supply to the fire alarm system includes an auto-starting emergency generator, it must be tested monthly;
  2. If the standby power supply to the fire alarm system is provided by vented batteries, they should be visually inspected. All vented batteries and their components must be checked by a competent individual on a quarterly basis.


In addition to the weekly and monthly tests conducted by the users, it is very important to carry out regular inspections and testing to identify and rectify faults such as false alarms.

These inspections are much more detailed and, due to their specialist nature, must be carried out by a competent individual whose competence can be assured by third-party certification, preferably employed by a fire alarm servicing company, such as Calder Security,

The recommended period between these inspections must not exceed 6 months. Failure to implement them within the time frame will result in the system not being compliant with British Standards 5839.

Functions included in periodic testing and inspections of the system include visual inspections of the manual call points, automatic fire detectors, and fire alarm devices, with particular focus on any changes to the building’s structure, occupancy levels, and use.


According to the UK fire alarm regulations, someone competent and reliable must be chosen to install and service your fire alarm. They require that the competent person(s) must:

  • Understand the various types of fire alarm systems and be familiar with all the different models,
  • Be able to identify the grades and categories of fire alarm systems, and
  • Have a good knowledge and understanding of the British Standard BS 5839.


At Calder Security, we offer you a comprehensive solution for all your fire safety needs that include professional installation, maintenance, monitoring, and repair.

We understand that every property is different and the specification of the system depends on several factors including the type and size of the building, the number of occupants, and how high risk it is.

We can help you cut through all that and advise you on the best fire detection system for your building that complies with British Standards, HSE, Building Regulations, and Fire Officer Guidelines, in addition to meeting the requirements of business insurance.

We also understand fire regulations and provide professional maintenance checks and reminders for when the checks are due to help you stay compliant with the law. We work fast to restore your fire alarm system to excellent condition and always strive to meet your expectations.

We offer various levels of monitoring via a 24-hour monitoring centre using Dualcom and BT Redcare signalling, which is the most secure alarm monitoring system and the largest supplier of intelligent alarm signalling services in the UK.

If your system starts to malfunction, you can rely on our highly skilled engineers to restore your system to full working order in one visit. We offer a 24-hour call-out service for customers and can also repair fire alarms not installed by us thanks to our extensive knowledge and experience.

Contact us here or call us today free on 0800 612 9799 to talk to our experts right away!

Photo by Christian Allard on Unsplash