Causes of Fire in Homes and How to Prevent It
Fire Safety in the Home
A fire in the home can be a devastating event, damaging property and possibly causing death or personal injury. While freak events can start a fire, many of the causes are preventable. This hub outlines the most common ways a house fire can start and gives some tips on how to stay safe and prevent disaster.
What Are the Most Common Causes of House Fires?
- Electrical faults in socket outlets, lighting, wiring and appliances
- Open fires and radiant electric fires
- Falling asleep while smoking
- Chip pans and other cooking equipment
- Children experimenting with matches and lighters
- Flammable liquids catching fire
- Chimney fires
Prevention is the Key to Safety!
We can stop fires by using our heads and taking precautions!
Can Electrical Faults Cause Fires?
Loose electrical connections, damaged insulation, and inadequately rated cabling are all potential fire hazards
- Electrical wiring should be in good condition. Socket outlets are a fire hazard if wiring isn't screwed down tightly by screws in terminals, or the brass strips inside a socket don't firmly grip the pins on an inserted plug. This can cause arcing, overheating and in extreme cases a fire. It's normal for a BS1363 plug (British/Irish style plug with an integrated fuse) to become warm if powering a high powered appliance because of current flowing through the relatively high resistance of the fuse. However if a plug becomes overly hot, check for loose connections. The cord/flex of an appliance should also be inspected for damaged insulation which could expose the cores in the cable. Don't run flexes under mats or carpets where they could become damaged
- Screws and nails inadvertently driven through cables buried in walls can cause leakage of current into moist timber and potentially start a fire. A GFI (Ground Fault Interrupter), also known as an RCD (Residual Current Device) may shut off the power in this scenario. Make sure your electrical panel has one of these fitted and upgrade if necessary.
- Don't leave high power appliances which are fed with power from a socket outlet or time switch such as driers, oil filled radiators and washing machines, unattended while in bed or out of the house. I have come across a couple of situations where loose connections inside socket outlets and time switches have caused a meltdown. Fortunately smoke was discovered before any further damage was done
- Keep ventilation slots of electronic devices and convector heaters unobstructed
- Some power adapters/chargers can run quite hot. Make sure they aren't covered and can cool properly. Don't leave them on beds, switch off when not in use and don't leave unattended
- Don't leave electric blankets turned on for extended periods to avoid overheating. Also the heating element in a blanket can eventually break due to metal fatigue (from constant flexing). This can lead to an arc in the element, potentially setting the blanket on fire. So replace when the lifespan recommended by the manufacturer's has been reached
- At Christmas, don't leave Christmas tree lights switched on while you are out of the house or in bed. Before they are placed on the tree, ensure all bulbs are pushed firmly or screwed tightly into sockets. Check for damaged insulation or loose wires.
- Make sure your home wiring is up to standard, cables are properly rated to carry current and electrical circuits are protected by the correct size circuit breakers
Can Batteries Cause a Fire?
Batteries have a positive and negative terminal. If these terminals are connected together due to contact with a metal item, e.g keys, metal foil, tins etc, this is known as a short circuit. A large current will also flow causing the batteries to overheat or even explode. Sparks can also be produced at the terminals. All of these scenarios can potentially result in a fire.
- Lithium ion batteries used in phones, tablets and laptops have a high energy density. Electronic circuitry in chargers in theory should prevent overcharging. However electronics can fail and batteries can overheat and catch fire. Remember what happened to the Boeing 787 Dreamliner? So unplug these devices when unattended. Don't leave laptops on a flammable surface overnight, e.g. a sofa, even if not being charged
- There have been stories of remote controls overheating and catching fire due to the buttons being permanently pressed down when the control gets stuck down the side of a sofa cushion. It might be an urban legend but don't test whether or not it is true!
- AA or similar type batteries can potentially start fires if left in pockets of clothing along with keys or other metal items which can cause a short circuit. The same goes for leaving them in drawers or boxes where they can inadvertently make contact with conductive items. Store them side by side, ideally in a plastic container so that there is little chance of this happening. Stick a piece of adhesive tape over the terminals of 9 volt batteries (the small square ones) to stop them short circuiting
Flammable Materials are a Potential Fire Hazard
- Keep flammable material off kitchen hobs to prevent fire if knobs are accidentally turned on
- Chip pans can ignite and you must never run with the pan to the door to get it out of the kitchen. You could trip and spread burning oil over the floor. Never, ever throw water onto a chip pan fire. Oil in the pan can be at a temperature of 300 C or nearly 600 F. At this temperature, water will boil explosively when it hits the oil. This will fling thousands of oil droplets into the air which will ignite instantly creating a mini fireball which can cause serious facial burns. The first thing to do is turn off the power to the hob or turn off the gas, Then extinguish this type of fire with a specially designed fire blanket or a wrung out wet towel
- Don't leave aerosol cans or gas cylinders on window sills or in the sun where they could potentially explode and start a fire
- Keep lighters, matches and flammable liquids in a secure place away from children
- In a garage/workshop, keep gasoline, diesel and other flammable liquids in a safe location away from sources of heat, strong sunlight and sparks. Sawdust and wood shavings should be cleaned up regularly. Rags which have been used to wipe spills of flammable material should be burned or kept in closed tins and disposed of safely. When angle grinding, direct sparks outdoors or in a direction where they cannot land on flammable material. Ensure you have the proper classes of fire extinguishers ready for use
- A build up of lint in a drier is a potential fire hazard. Lint blocks filters and eventually even the outlet / hose. This can cause a drier to overheat as air is prevented from circulating through the machine. Eventually the whole thing can ignite. This is another reason why high power appliances shouldn't be left unattended for long periods.
- Fire lighters/starters should be kept in sealed tins (e.g a cookie tin)
Keep Your Chimney Clean and Your Fireplace Safe
- Never leave an open fire unattended without a spark guard. Don't leave papers in or near the hearth, which could catch fire. This is a potential danger at Christmas when there is lots of wrapping paper about. Don't throw sheets of paper into the fire, which could blaze up and set the chimney on fire
- Clean chimneys at least once a year to avoid fires. Ensure the masonry of the chimney in the attic isn't cracked and compromised which could lead to flames entering the attic space during a chimney fire. This is a serious event which could lead to a roof fire if items are stored close to the chimney in the loft. A stainless steel flue liner can be used to overcome the problem of damaged flue liners
Naked Flames and Heat Sources Start Fires
- Empty ash trays if they are going to be left unattended for a period. Cigarettes are a potential fire hazard if someone falls asleep while smoking
- Candles should be held securely in holders and away from flammable materials and Christmas trees, and never left unattended for long periods
- According to fire fighters, shaving/magnifying mirrors sometimes cause fires when they focus the rays of the sun onto flammable materials such as curtains. Keep magnifying mirrors out of the sun
- Electrical radiant fires, grills, toasters, and any other device with an element which gets hot can potentially start a fire. Heaters should be kept at a safe distance from furniture. Outdoors, halogen floodlights should be mounted so that flammable materials, e.g. wood, plastic, dried vegetation from climbing plants are kept at the minimum rated distance from the face of the fitting
- If there is a power cut, turn off all heat sources which could start a fire when the power comes back on. E.g. kettles, irons, radiant electric fires and cooking hobs.
- Kettles shouldn't be left plugged in without containing some water. A safety thermal cut out should operate if a kettle is switched on inadvertently when empty. However this may fail, and the element could rapidly overheat, potentially starting a fire
- When you remove the ashes from a fireplace, store them outdoors until they cool down and can be disposed of. Ashes can remain hot for over 12 hours and contain red hot unburned embers. Leave them for a couple of days before disposing of in a trash can/ wheelie bin. Alternatively scatter them outdoors, away from dry grass, leaves, bushes or other combustible material.
Fire Extinguishers Types and Fire Blankets
Make sure you have a fire blanket and kitchen fire extinguisher. A powder extinguisher is general purpose and suitable for class A, B and C fires.
Where to Install Smoke Alarms?
Install plenty of smoke alarms throughout the house. Check the installation instructions as regards suitable locations for the alarms. Usually they should be kept a minimum distance away from edges of ceilings and tops of walls and corners of rooms to avoid "dead spots" where smoke doesn't travel to. Drafty locations can also keep smoke away from alarms, preventing smoke detection. Check regularly that alarms are functioning by pressing the test button. Don't use rechargeable batteries in smoke alarms because the voltage can drop rapidly when they become flat, preventing the low battery beep from activating.
Install an Intruder Alarm
A security system is also advantageous to deter burglars who could potentially start a fire. Your options are wired or wireless and alarms can be setup to send you out text messages on activation or report to a monitoring service who'll contact you when the alarm goes off.
Don't use water on electrical fires or flammable liquid fires (e.g. gasoline, kerosene, diesel)
Leave the mortice lock on one door unlocked or leave a key nearby which can be used in an emergency. Don't leave keys near a mail box though as they can be fished out by burglars! It's a good idea to have a small LED torch on the window sill of every window which you can use to aid your exit in the dark if the power goes out
You can buy small emergency lighting units which can be plugged into the sockets in a corridor. These turn on if the mains power is lost
Keep corridors free of obstacles so that you can make a quick exit if a fire breaks out in your home. In your garage or workshop, don't leave stuff on the floor which you could trip over or obstruct you on the way to the exit. Also make sure there is nothing leaning against, or moved in front of the exit which could take time to move in the event of a fire
It should be possible to escape from all windows upstairs in a house. Keep the key of the windows accessible so that they can be unlocked in an emergency
Keep Doors Closed to Starve a Fire of Oxygen and Stop it Spreading
Oxygen is a requirement for combustion, so keep doors closed when your house is vacant or while sleeping. Starving a fire of oxygen could slow its development and propagation through the house structure, providing vital minutes during which smoke alarms are triggered and an escape made to safety outside the building.
You can install hardwired emergency lighting units in your home which are trickle charged by a mains source. These units contain a battery and light up if the power shuts off during a fire. Another alternative are small units which plug into a wall socket. Again these are battery powered and activate during a power cut. They can be strategically located in corridors to light the way to an exit.
NFPA Educational Messages Desk Reference - Guidelines for Prevention of Fire (PDF File)
Questions & Answers
© 2012 Eugene Brennan