Smoke Alarms

Year on year, over 7,000 smoke alarms fitted in dwellings failed to operate, just under half of which can be attributed to missing batteries or batteries fitted incorrectly.

With the type of materials and level of fire loading in modern dwellings today, fire hazards have increased considerably. If a fire occurs in your home it can rapidly engulf your house with smoke and flames. Annually in the UK, over 70,000 fires occur in the home killing around 700 people and seriously injuring 15,000 others.

The products of fire, mainly toxic gases and smoke, account for the majority of fatalities in the home, with most of these occurring during the night hours. A smoke alarm gives you those precious life saving minutes to put your fire plan into action and get you and your family to safety.

It is with this in mind that householders are being encouraged to fit domestic smoke alarms in their premises. Although it must be borne in mind that detectors do not prevent fire, these alarms will operate when fire occurs, arouse the family in its early stages and increase the chance of escape.

There are many types of alarm on the market and they cost from around £5. You can buy them at most DIY, hardware and electrical shops and some supermarkets. Always look for an alarm which conforms to the British Standard. This means that the alarm has achieved a standard acceptable to the British Standards Institution (BSI). Smoke alarms should meet BS5466 Part 1 and will carry the well-known kitemark.

Operation of Detectors

Smoke alarms, or smoke detectors as they are sometimes known, are small devices, about the size of a hand. They are fitted to the ceiling and are able to detect fires in their earliest stages and sound a loud warning alarm. This alarm can give you those precious few minutes of warning time which will help get you and your family out safely.

Ionisation type smoke alarms are the most common type of smoke detector in domestic use. They are designed to detect both visible and invisible products of combustion and are effective in detecting fire in its incipient stages, continuously monitoring the surrounding atmosphere.

Optical smoke detectors which are activated by larger smoke particles are also available for use in kitchens. Another detector on the market for use in kitchens is a combined heat and carbon monoxide detector. Both of these detectors are designed to obviate nuisance alarms in kitchens caused by cooking. They are recommended to be interlinked with other ionisation type alarms in the house.

Detector Location

Household fires are especially dangerous at night when the occupants are asleep. It is important therefore to ensure that detectors are located correctly to waken sleeping occupants when they operate.

If you live in a flat or bungalow, one smoke alarm should be enough to provide you with early warning or fire. The detector should be located in an area between the sleeping and living accommodation areas. If your house has more than one level, one alarm should be fitted at the bottom of the staircase and an additional alarm on each upstairs landing. For extra protection you can fit alarms in any room where you think a fire may start, e.g. the lounge or bedroom. Do not fit an alarm in the kitchen or bathroom, as the steam or cooking fumes may trigger the alarm. Cigarette smoke will not normally set off an alarm.

If you have more than one alarm, then they should be interconnected. For extra safety, fit a smoke alarm in each room except the kitchen, bathroom and garage. You should check with an electrician before trying to link the alarms yourself.

If possible you should fit a hard wired smoke detector with a battery back up. These are more expensive but ensure a greater level of safety.

Mounting

A smoke alarm should be fitted to the ceiling within 7 metres to the door of the living room or kitchen (but not too near the kitchen so as to avoid nuisance actuation) and within 3 metres of the door to the bedroom. Additionally, the smoke alarm should be kept at least 30 centimetres (12 inches) away from any wall or light fitting or air conditioning/ heating outlet.

Testing & Maintaining

Once a Month

Smoke alarms should be tested weekly by depressing the test button. If this is difficult to reach, the button can be pressed by a brush handle or some similar object. Detectors are also available which can be tested by passing a beam of light over the unit. These are particularly suitable for rooms with high ceilings or for use by elderly or disabled persons. Hard wired detectors should be tested on mains failure by isolating the electricity circuit before testing.

Once a Year

The battery if fitted should be replaced at least once a year or if the low power warning signal sounds. Make a note of the date of the change. Alarms are now available which incorporate an integral 10 year battery which obviates the need for annual replacement. These detectors must be replaced however after 10 years. Detectors should be lightly vacuumed annually to remove dust etc. Vacuum the inside of the alarm to ensure that dust isn't blocking the sensor chamber.

Features

A number of companies manufacture smoke alarms It is therefore not possible to list all of the recommended detectors, but the following features should be looked for when purchasing.

• It should have a fail-safe device built in either: a small LED cell which flashes periodically to show the detector is working efficiently; or give a visual or audible warning that the battery is low and requires changing. (The power supply is normally a battery which has an operating life of one year).
• The warning signal should produce at least 85 decibels. This is a minimum standard, a louder signal may be required depending on the location of the detector in relation to the bedrooms. Wherever possible, carry out an audibility test before final fixing to ensure the detectors will wake the household when actuated.
• The smoke detector components should be in accordance with British Standard 5446- Part 1: 2000.

People With Hearing Impairment

Many people whose hearing is not severely impaired are still able to hear a conventional smoke alarm. It is a good idea to link two or more alarms. This way smoke detected in the living room will set off another alarm in the bedroom. An electrician will be able to advise you about linking the alarms.

For people who would not be able to hear a conventional smoke alarm there are special devices available which make use of a vibrating pad or flashing light instead of the auditory signal. These have a standard detector unit which is connected to a flashing light and a vibrating pad which can be placed beneath a pillow to raise the alarm during sleep. The vibrating pad alarms are particularly useful for blind-deaf people. Detector units can be interconnected when more than one is required.