A Guide to Gas Safety at Home for Students, Tenants & Homeowners: Gas Leaks, Fires, Explosions & Carbon Monoxide Poisoning,
Deborah J Percy
Copyright 2011 Deborah J Percy
Smashwords Edition
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Contents
Introduction
What is natural gas & LPG (propane)
What to do in a gas emergency
Part 1 Carbon monoxide
Part 2 Gas leaks, house fires and explosions
Part 3 Gas safety at home.
Part 4 Sources and resources
Thanks to:
My gas engineer husband for help in writing this.
D McAbee for cover photograph
Any mistakes are my responsibility.
I am Deborah Percy a writer and the Director of Tara Maintenance,
a Gas Safe Registered business that installs gas heating in homes in Kent.
Introduction
Gas is used in our homes for heating and cooking. Mains gas is piped to most areas and is also called natural gas. Houses off the grid, usually in more rural locations, might use bottles or cylinders of stored propane gas which is also known as LPG or Calor Gas.
The domestic use of gas is very safe but still there are dangerous situations and avoidable deaths every year.
Over a five year period between 2005 to 2010 there were at least 78 gas related deaths in the UK and in excess of 1,300 further people directly affected by 902 incidents of explosion, fire, carbon monoxide spillage or other serious gas incidents according to official HSE statistics.
This booklet explains all you need to know about gas safety in your home. It includes what to look for when buying new gas appliances, why you should have a carbon monoxide alarm, what is the difference between a boiler service and a landlord or homeowner gas safety check and danger signs to watch out for.
Regulations referred to in this booklet apply in the UK but similar safety standards should be universal.
The dangers are related to incorrect installation, poor maintenance or misuse of gas pipework or appliances. The risks are:
* Carbon monoxide poisoning and death
* Gas leaks
* Fires
* Explosions
The first section of the book is about Carbon Monoxide (CO), which can be a by-product of using a gas appliance and accounts for about 30 accidental deaths per year in the UK and 170 in the US. CO is deadly, even in very small doses, but there is plenty you can do to avoid carbon monoxide poisoning.
This book will explain the signs of dangerous carbon monoxide levels and will tell you what to do if you suspect you may have been poisoned. There is also information about how to choose and use a Carbon Monoxide detector alarm.
The second section is much smaller, about gas leaks, house fires and explosions.
The third part of the book is about what you can do to ensure safety at home. It includes:
* What to look for when choosing a gas fire or gas cooker;
* How to find a gas safe registered engineer;
* Details about the Homeowner/ Landlord Gas Safety Inspection (CP12);
* Information about having appliances such as boilers and fires serviced.
What is Natural Gas, Propane & Liquid Petroleum Gas?
Mains gas, which is piped to our homes, is also called natural gas. A fossil fuel created from the transformation of buried plants and creatures over millions of years. It is mostly methane with a small trace of other gases. Methane molecules are comprised of one carbon atom and four hydrogen atoms, hence CH4.
An odour is added to natural gas and to propane so that leaks can be easily detected.
Propane is commonly called Liquid Petroleum Gas (LPG). In the UK it is also known by brand names such as Calor gas. Propane is used where piped natural gas is not available. The same gas appliances (fires, boilers and hobs) can be used with slight adaptations.
Propane is C3H8 and an odour is added so that leaks can be detected. For safety it is important to know that propane is heavier than air, a leak will result in a pool of gas. For this reason it should not be stored in basements.
Only qualified people who are on the Gas Safe Register are allowed to work on gas pipework or gas appliances in the UK.
What to do in a Gas Emergency?
Turn off gas if safe to do so.
Extinguish any naked flames or sources of heat.
Open doors and windows to ventilate and disperse the gas.
Do not flick any switches or cause any sparks.
Do not smoke.
Evacuate the building and telephone the relevant emergency number listed below.
England, Scotland and Wales:
For Natural gas, call the National Gas Emergency Service Freephone Number: 0800 111 999
Northern
Ireland:
For Natural gas, call the Northern Ireland Gas Emergency Service: 0800 002 001
Isle
of Man:
For Natural gas, Towns gas and LPG, call Manx Gas Ltd: 01624 644 444
Guernsey:
For Mains gas and LPG, call Guernsey Gas Ltd: 01481 749000
Jersey:
For Mains gas and LPG, call Jersey Gas Company Ltd: 01534 755555
For
non-urgent queries you should read this ebook or check the HSE gas
website or, if in the UK, telephone their free Gas Safety Advice Line
freephone 0800 300 363
9.00am and 5.30 pm Monday to Thursday
9.00am to 5.00pm on Friday (excluding bank holidays).
Part 1
Carbon Monoxide
What is Carbon Monoxide?
Carbon Monoxide (CO) is an invisible gas which has no smell. Each molecule is made of one carbon and one oxygen atom, hence it is known as CO. It is produced when fossil fuels are partially burned. It is present in vehicle exhaust fumes and in out of control fires.
Fire needs oxygen to burn. In an enclosed environment the oxygen will be used up by the process of combustion (i.e. a fire) and then there is the risk of CO being produced. In the same way, CO can be produced when gas appliances are not running correctly.
Why is Carbon Monoxide Dangerous?
Each year about 30 people in the UK and 170 in the US are killed by accidental carbon monoxide poisoning at home. All of these deaths are so easily preventable and the real figures may be much higher. There are official statistics for accidental CO fatalities but it is widely thought that these may be just the tip of the iceberg because levels of CO in houses are not routinely checked, the symptoms may go unrecognised and the deceased are not routinely tested for CO poisoning.
Carbon Monoxide is dangerous at even very low levels. Less than 1% of Carbon Monoxide (CO) in a room will render someone unconscious and dead within minutes because it reduces vital oxygen levels within the blood. The greatest effect will be felt by the smallest people, children and animals.
Some of the symptoms associated with CO poisoning are confusion, dizziness, intoxication and chest pains. These may all be experienced briefly before becoming unconscious when CO levels are high.
Small exposure over a long time period can also be detrimental to health, even if severe symptoms are not experienced. Normally CO should not be present in the home, however, near a gas stove low levels of between 5 to 15 parts per million are typical and sometimes higher (according to the US Environmental Protection Agency website on Indoor Air Quality), which is why kitchens with gas appliances must have ventilation.
The ventilation requirement are detailed in Part F, Building Regulations and the Gas Safe Register Technical Bulletin 005(A). For most purposes it is enough to know that kitchens should have windows or a door that opens to outside or to a conservatory that also has windows and doors. Very small kitchens or those without enough windows may require an extract fan.
The background level of CO that is considered safe in a working environment for up to eight hours per day is less than 25 parts per million (ppm). To put this into perspective, this is just 0.0025% of the atmosphere, which is comprised of roughly 21% oxygen, 0.04% carbon dioxide and 0.002% neon gas among other things. For short periods higher levels of CO may be harmless but sustained levels over 70ppm can have a detrimental effect on health and continuous exposure to concentrations over 150ppm (0.015%) can be dangerous and result in death.
Modern CO alarms are very sensitive and are triggered by levels over 30 to 70ppm within a specified timescale. More about CO detectors later.
Signs of a Carbon Monoxide Spillage in the Home
It is important to note that there might be a carbon monoxide spillage in your home with no tell tale signs.
Some things to watch out for are:
* Black marks around gas fires
* Sooty black marks around boilers
* Orange and yellow flames, they should be blue
* Increased, excessive condensation
* Pilot lights that frequently blow out
* Blocked flue exits outside the home, often blocked by leaves
* Feeling ill at home but OK when away or at work, especially with headaches
* Other occupants also feeling ill at home but OK when out of the house
* Make sure there is ventilation in any kitchen which has a gas cooker or hob
* Do not run an engine in a garage, even with the door open
Symptoms of Carbon Monoxide Poisoning
CO poisoning may go undiagnosed because the symptoms are very general and can be like the flu without a temperature, the first and most common being a headache. Carbon Monoxide (CO) poisoning can have long term health consequences such as brain damage, heart damage and urinary incontinence.
A short list of common symptoms would include headache, nausea, dizziness, confusion, tiredness, vomiting, shortness of breath and chest pains. The sufferer may experience a combination of these.
Who is at Risk from Carbon Monoxide (CO)?
There are very few fatalities from CO poisoning in the home so statistically the risks are very low, about 1 out of 2 million people will die in this way this year in the UK.
This is not the whole story, however, these deaths are easily preventable and they leave grieving families. More people survive CO poisoning and many people may be experiencing ill health without the cause ever being ascertained. The true extent of the problem is almost certainly unknown because CO leaks and poisoning are not routinely tested for.
In the past 14 years just over 500 deaths in the UK can be attributable to accidental CO poisoning. Contrary to some common misconception these are not mostly students living in bed-sits and cheap flats. Statistics compiled by the British charity CO Gas Safety reveal that most are mature people and owner occupiers.
According to CO Gas Safety, the appliances and association with cause of death breakdowns down as follows:
13% of deaths related to cookers/hobs/grills.
25% of deaths related to room heaters & portable room heaters
25% of deaths related to boilers.
6% of deaths related to engines.
5% of deaths related to generators.
4% of deaths related to water heaters.
A further analysis of their figures also shows:
72% were over 41 years of age.
19% were between the ages of 71 to 80 years old.
58% of those who died at home were owner occupiers
There is a disproportionate high risk from solid fuel and recent changes to Building Regulations requires homes with solid fuel installed after October 2010 to also have CO alarms.
Treatment
for Carbon Monoxide (CO) Poisoning
If you suspect CO poisoning it is vital that you report to a medical practitioner to be tested and treated. This also applies even for low level exposure over a long period. Treatment is given in hospital and involves breathing pure oxygen.
Buying a Carbon Monoxide (CO) Detector or Alarm
A good alarm is not expensive, you should expect to pay about £30 in the UK. Look for these features:
* Compliant with safety standards, EN 50291:2001 in the UK (in the US UL 2034)
* has an audible alarm
* will indicate when battery life is low
* has a battery back up if wired to mains electricity
* is easy to use
There are many suitable alarms, one which is widely recommended is the Honeywell H450EN Carbon Monoxide Alarm. It currently retails for £30, requires no setting up, the batteries will last 7 years, it is maintenance free and guaranteed for 6 years.
Most CO alarms are triggered when there is a certain level of CO present for a specified time, so it is not triggered by brief rises in CO. The H450EN alarm is triggered when CO levels are measured at any one of the following:
* 50ppm for between 60 to 90 minutes
* 100ppm between 10 to 40 minutes
* 300ppm in less than 3 minutes
Where to Place a Carbon Monoxide Alarm
The Carbon Monoxide Alarm should be fitted in the same room as the gas appliance, mid way up the wall. A CO alarm should be bought for every room which has a gas appliance.
What to do When the Carbon Monoxide Alarm Goes Off
If the alarm goes off do not ignore it. Open windows and doors for ventilation and breathe fresh air immediately and then turn off the gas appliances if it is safe to do so.
The CO level which trigger an alarm may be high enough to be deadly if you do nothing. Carbon Monoxide poisoning can impair your judgement. At higher levels you will have only minutes before you may be rendered unconscious so pausing within the house could prove fatal.
If the alarm is being activated at 100ppm or lower most adults will be able to turn off the gas without a risk to their health.
If the alarm is activated at a low reading you should do the following:
* Open windows and doors to ventilate
* Turn off the gas at mains or gas appliances
* Do not turn on the gas appliances again until they have been checked by a gas safe registered engineer
* Do not sleep in the room until the CO has cleared and make sure no-one is able to turn on the gas appliances
* Telephone a registered gas engineer who can test levels of CO in the home and identify the cause of the problem
Where Does Carbon Monoxide in the Home Come From?
Many common sources of CO inside the home are:
* fires
* cookers
* hobs
* stoves
* boilers
* furnaces
* water heaters
* generators
* engine powered tools
Faulty
appliances and blocked chimneys, blocked flues or inadequate
ventilation are frequently associated with CO spillages.
Carbon monoxide can enter from outside or from a neighbouring building. Traffic, running car engines in garages and using generators indoors are also common sources.
Using petrol powered tools or generators in an enclosed space can be a problem and accounts for many deaths, especially in the US. Open doors or windows might not provide adequate ventilation for these machines.
Part 2
Gas Leaks & Explosions
The biggest risk for domestic gas users is from carbon monoxide poisoning, probably because CO is undetectable by people. The other well known risks associated with gas are, of course, fire and explosions. These are far less common than you might imagine. The figures for the UK suggest there are less than 30 fires or explosions per year involving mains gas or LPG. There are a number of reasons for these low figures, in contrast to those for CO poisoning:
* Gas leaks can be detected by their smell.
* If there is a fire it can be seen and might be tackled when small.
* The population is well educated in relation to what to do if there is a smell of gas
Domestic Gas Explosions After a Gas Leak
A small leak over a fairly short time can allow enough gas to build up for a nasty explosion, which could reduce a whole house or series of houses to rubble. An odour is added to natural gas and LPG so that we can detect gas leaks. If you smell gas you should:
* Turn off gas at mains,
* Open doors and windows for ventilation to disperse the gas,
* Do not use any naked flames,
* Do not use any switches until smell of gas is clear,
* Telephone National Grid's Gas Emergency (formerly Transco) 0800 111 999 or other emergency numbers listed in the introduction to this booklet,
* Telephone your regular Gas Safe Engineer if you have one.
How to Avoid Gas Leaks Leading to Fires & Explosions
Gas explosions have been known to happen when the owner has done everything right including having an annual gas safety check. This is because the gas can build up quite quickly, it requires less than 5% of the air in a room to be natural gas or propane for there to be an explosion. An explosion does require either some heat, a spark or a flame.
Where has the gas come from?
* All may be in good condition inside the house but gas can seep in from old, perished pipework from the other side of the gas meter.
* Leaking gas builds up in basements and in cavities.
* Or have you forgotten to ignite an old hob or gas fire?
There are extra things beyond the most obvious that the most vigilant person can do:
* Modern gas appliances should all have Flame Failure Safety Devices (FSD) so that gas will not spill out when unlit (see part 3).
* Do not store LPG propane in a basement.
* Check basements for the smell of gas and air basements regularly.
The most basic and obvious precautions are:
* Have all gas appliances regularly serviced and pipework checked by a qualified gas safe registered engineer, once a year would be usual.
* Make sure you have modern gas appliances with the best safety features installed.
* Ensure you gas hob, gas fire or room heater has a Flame Failure Safety Device (FSD).
* Your fires and heaters should also have a Oxygen Depletion Sensor (ODS).
* For more information about FSDs and ODSs see Part 3.
Part 3
Gas Safety at Home
Gas Safety Devices
A flame supervision device (FSD), also called Flame Failure Safety Device, will turn off the gas supply to the burner if there is no flame. Modern gas ovens always have FSDs as do flue-less fires but grills and hobs and some gas fires might not have these.
Without an FSD there is the risk of a build up of gas if the burner is turned on but not lit or if for any reason the flame goes out. As from 1 April 2009 it has been a requirement that all gas appliances in flats and other multi-dwelling buildings are installed with flame supervision on all burners. For me this is a level of safety that I want in my house.
An oxygen depletion safety device (ODS) is another feature to look for which is typically found on modern gas fires. Working with the FSD it will turn cut the flame and the gas when oxygen levels in the room fall. Falling oxygen levels are associated with unconsciousness and carbon monoxide spills.
Be sure to have any gas appliance fitted by a qualified gas safe registered engineer, as required by UK law. This includes moving an oven, even one with a simple bayonet fitting. The gas engineer will ensure it is working safely and that there is suitable ventilation in the room.
Choosing a Gas Cooker, Hob or Grill
* Gas ovens and hobs are flue-less appliances so the kitchen must be well ventilated to the outside, this is required by regulations.
* Gas cookers must not be used to heat the home because they are not designed for this purpose and there is a risk of carbon monoxide poisoning.
* An FSD on all burners is required in a building which has multiple dwellings, such as block of flats.
* In my opinion FSDs are desirable in any home.
Choosing a Gas Fire
There are many safety regulations regarding gas fires. To be safe make sure:
* Fires are installed by a qualified gas safe registered engineer
* Any ventilation in the room required for the fire is not be covered up or removed
* There is a FSD
* There is an ODS
* Fan assisted flue is preferred by many gas installers rather than a flue-less gas fire
Gas Fires & Gas Appliances in Bedrooms
There are strict rules about gas fires in bedrooms. A gas appliance without a flue must not be used in a bedroom.
According to current UK gas safety regulations the following ARE NOT permitted in bedrooms:
* Flueless gas fires
* Any open flued appliance with more than 14 kilowatts gross input
* Any smaller open flued appliance which does not have an atmosphere-sensing device
The following ARE permitted in bedrooms:
* Room sealed appliances which means there is a fan assisted flue
* Small open flued appliance, with less than 14 kilowatt gross that has an atmospheric-sensing device
Note, the difference is that an open flued appliance takes air from the room and waste is sent out of the flue. When there is a room sealed appliance with a fan assisted flue the air used is drawn from outside and there is no impact on the air in the room.
Smoke Detectors and Carbon Monoxide Alarms
All homes should have smoke detectors and this has been a part of UK Building Regulations for new houses for a number of years. There is no legal requirement for homes to have CO detectors unless they have solid fuel.
There are many organisations that promote the fitting of CO alarms in all homes. CO alarms are encouraged by the UK Health and Safety Executive and the Carbon Monoxide – Be Alarmed! Campaign, which is run by Energy UK on behalf of Britain’s six major gas and electricity companies.
The Gas Safety Inspection for Landlords and Tenants
Landlords must provide safe gas services for tenants as defined in the Gas Safety (Installation and Use) Regulations 1998 in the UK. By UK law, any landlord must arrange for a Gas Safe Registered engineer to check gas appliances, flues and pipework regularly and a certificate should be issued at least once a year. There must be a gas safety check at the beginning of each new tenancy (Code of Practice, HSE).
Landlords are those who own property which is entirely or partly rented to tenants, including rented houses, holiday homes, bedsits or rooms in a shared house and in guest houses.
The landlords' responsibilities relating to gas in the property are:
* to ensure gas appliances and pipework within the building are safe;
* to have an annual check carried out by a register gas engineer (sometimes called a CP12 inspection);
* to have a safety check between tenants;
* to give the tenant a copy of the Gas Safety Inspection Report,
* to have gas appliances serviced regularly.
What
is the Homeowner & Landlord Gas Safety Check?
The
Landlord's Gas Safety Check is:
* a visual inspection for safety
* NOT a pass or fail test
* a written record of what is found at the property
The
inspector will make recommendations. If all is perfect the only
recommendation will be to have appliances serviced and a routine
inspection when it is due.
According to the law in order to
complete the certificate the engineer will test all flues and gas
appliances at the property. The engineer will check:
* that the flue is not blocked and it works
* that there is adequate ventilation
* the operating pressure or heat input or both for all gas appliances in the property
* that the appliances work safely
The certificate will include the following information:
* the date of the inspection and the property address;
* full details of the inspector, including his or her registration number;
* full details of all the gas appliances including their locations;
* any defects identified and details of any corrective action undertaken;
* whether a service has been carried out and on what date, note, the safety check is not the same as a service.
Will
the Boiler be Serviced at the Same Time as the Landlord Safety
Check?
A landlord gas safety
certificate does not require the same level of attention as a
service. There are benefits to having appliances serviced regularly
and manufacturers usually recommend gas appliances are serviced
annually.
In addition landlords are legally required to ensure
gas appliances are correctly maintained, booking a regular service
will ensure this obligation is met.
Briefly the differences
are:
* The Landlord Certificate is more paperwork and a visual inspection for safety;
* The Gas Appliance Service ensures it is working efficiently as well as safely.
There
is, of course, overlap, both require a visual inspection of
appliances for correct and safe installation, to ensure ventilation
is adequate and to ensure the flue is working safely.
How to Find a Gas Safe Registered Engineer
In order to work on a gas appliance or pipework a person must be competent to do so as defined by the Gas Safety (Installation and Use) Regulations 1998. Anyone not working in their own home must be competent, qualified and registered with the Gas Safe Register, formally Corgi.
Heating engineers might advertise locally and display the Gas Safe logo but it is always worth checking the registration details with the Gas Safe Register, where you can also find a list of local registered engineers.
Part 4
Sources and Resources
This section introduces you to organisations and websites that are reliable sources of information, in no particular order. I have used these sources for writing this book and other articles.
The UK Health & Safety Executive
A national regulatory body concerned with safety in the work place. The HSE has a role in ensuring gas safety for all people at work and at home. The remit extends to all gas related matters including gas installations in the home. Dangerous incidents involving gas should be reported to the HSE.
Gas Safe Registered engineers have a duty to report dangerous situations to the HSE who in turn have an enforcement role. The HSE oversee the registration of gas engineers, this is currently called the Gas Safe Register. http://www.hse.gov.uk/gas/
Tenants who have problems with landlords over gas safety issues can contact the HSE on 0800 300 363.
Gas Related Statistics collected by HSE are found at: http://www.hse.gov.uk/statistics/tables/index.htm
Gas Safety (Installation and Use) Regulations 1998 Approved Code of Practice and guidance can be viewed here, for free: http://www.hse.gov.uk/pubns/priced/l56.pdf
Gas Safe Register (GSR)
Managed by a commercial organisation but overseen by the HSE, almost anyone working on gas, natural gas or LPG in the UK, Isle of Man or Guernsey must be on the Gas Safe Register. http://www.gassaferegister.co.uk
Corgi - The Council of Registered Gas Installers
Corgi is trade organisation, membership used to be compulsory for gas engineers but this is no longer the case. http://www.corgi-membership.com
The US Natural Gas Supply Association
Exists to promote the interests of gas suppliers, they also produce the educational website. http://www.naturalgas.org
Energy UK
Represents gas and electricity suppliers. It also runs an excellent safety campaign to raise public awareness of Carbon Monoxide – Be Alarmed! http://www.co-bealarmed.co.uk/
The Carbon Monoxide and Gas Safety Society
An independent charity which aims to reduce accidents. This organisation collects and analyses useful statistics. It also has many sad stories behind the numbers. One page on the website lists all the names of those known to have been killed by a CO accident. http://co-gassafety.co.uk/
US Environmental Protection Agency
Protects human health and the environment by developing and enforcing regulations, giving grants, conduct studies and has an educational and informative role. The EPA website is a fountain of useful information. http://www.epa.gov/