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Fire Safety in the Home


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Fire Safety in the Home: Smoke Alarms

The simplest way to protect your family and home from a fire is by installing smoke alarms. They are fairly inexpensive to buy and easy to install.
Here, we take a look at where you should install a smoke alarm and the different types available. Before you buy your smoke alarm, check that they are safe and approved by looking out for the British Standard Kitemark or Loss Prevention Certificate Board (LPCB) symbols.


What are the different types of smoke alarms?

  • Ionisation

These are the most common type of smoke alarm and the most economical. They ionise the air between two electrodes. The small current, caused by the two electrodes, changes when smoke particles are detected - this makes the alarm sound. Ionisation smoke alarms are quick to detect small particles of smoke caused by fast moving fires (wood or paper), making them less suited for use in or near kitchens. 

  • Optical

Also known as a photoelectric smoke alarm, they contain an infrared LED that pulses a beam of light into the sensor chamber every few seconds, to check for smoke particles. The optical smoke alarm is better at detecting large smoke particles of slower-moving or smouldering fires. This type of alarm is ideal in bedrooms or hallways.

  • Heat

Heat or thermal alarms are sensitive to heat rather than smoke, giving them a slower reaction time, compared to smoke-detecting alarms. They are triggered when the room temperature reaches 58℃. Because they’re not triggered by smoke you can use them in your kitchen.

  • Combined Optical Smoke and Heat Alarms

Combined smoke alarms, also known as multi-sensor alarms, give you the best detection for both heat and smoke. This results in a quicker time for the alarm to respond as both sensor types will be monitoring - this reduces the risk of a false alarm. These types of smoke alarms are suitable for all over the house, with the exception of kitchens and bathrooms.

  • Battery powered alarms

As you can probably guess, these smoke alarms are battery powered. There are two types: your standard replaceable battery alarm, where you would need to replace the batteries every year, and a sealed 10-year smoke alarm - these are fitted with a long-life lithium battery in a sealed unit, so it won’t need replacing during its 10-year lifetime. You will need to replace the whole smoke alarm after 10 years, but you’ll save on replacement batteries each year.   

  • Mains powered alarms

​​​​​​​Mains smoke alarms are fitted to your home’s electricity supply, and will need to be fitted by a qualified electrician. You won’t need to replace batteries every year, but they do come with a backup battery inside, in case of a power cut. Building regulations state that any property built after 1992 will need to have at least one mains-fitted smoke alarm installed. 


Which smoke alarm should you choose, and where should they be fitted?

It’s recommended to have at least one smoke alarm on each level of your home, and the best place to fit your alarm is on the ceiling in the middle of a room, and in a hallway or landing area. 

Depending on where you want to place your alarm, some smoke detectors aren’t suitable for use in every room in the home. For example, certain types can’t be placed in the kitchen or a bathroom because smoke and steam could set them off. 

See the below breakdown of rooms in the home, and which type is most suitable:

  • Kitchen: heat

  • Bathroom: multi-sensor

  • Hallway, landing and stairwell: multi-sensor, optical, ionisation 

  • Bedrooms: multi-sensor, optical

  • Living room: multi-sensor, optical

  • Offices: multi-sensor, optical, ionisation

  • Garage: heat

Testing your smoke alarm

  • Battery operated: it’s suggested to test these at least once a month, and replace the battery every year. You can vacuum under the cover of your smoke alarm, with a soft-brush attachment, every few months to remove any dust that may interfere with the sensor.

  • 10-year sealed: you should test these every month to make sure it’s working correctly. You will need to replace the unit at the end of its 10-year life, or when it starts to make a quiet beeping sound, this indicates that the batter is low. 

  • Mains operated: the recommendation is to test them every month. If it starts to make a quiet beeping sound, it could mean the backup battery is going flat, so it’s an ideal time to change it.


If you are deaf or hard of hearing you can contact the Action on Hearing Loss Information Line on 0808 808 0123, textphone 0808 808 9000, or visit their website here.

If you need more information on which smoke alarm is best for you and your home or office, contact your local fire and rescue service for advice.