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FLAMERETARDANTSfor a changing society
EFRA (The European Flame Retardants Association) brings together the major companies which manufacture or market flame retardantsin Europe. EFRA covers all types of flame retardants: chemicals based on bromine, phosphorus, nitrogen and inorganic compounds.EFRA is a sector group of Cefic, the European Chemical Industry Council.www.flameretardants.eu
For further information about flame retardants, please contact:
Dr Phil Hope EFRA Sector Group Manager Cefic - The European Chemical Industry CouncilAvenue E. van Nieuwenhuyse 4 bte. 2 - B-1160 Brussels - Belgium Tel: +32 2 676 72 30 E-mail: [email protected]
CONTENTS
SAFETY
ELECTRONICSFrom static and bulky to portable, light and energy efficient
FURNISHINGFrom impractical to functional
BUILDINGSFrom cold and creaky to cool and cosy
TRANSPORTFrom slow to swift and from heavy to light
IN DETAILHow do flame retardants work?
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01 SAFETY
Over the centuries, our safety and welfare has been a priority and motivator for change - whetherat home, at work or in public spaces. Today, safetyis no longer just an option; it is required and expected of every product that we buy, use or find in our environment.
DEVELOPMENT OFNEW MATERIALS ANDTHEIR SAFETY
The nature of the structures andobjects which shape our urban environment have undergone a significant transformation during thecourse of the 20th century. Increaseddemand for more efficient, more affordable and more comfortable products has been the driving forcebehind an evolution in the way products are made. The use of traditional materials, such as wood,metal and animal hair or hides to make furniture, cars and appliances has been replaced by the use
of new materials, such as plastics,composites, foams and fibre-based fillings.
The materials which are now used toconstruct all sorts of structures and fittings in our immediate surroundingshave come a long way. One example ofthese huge advances can be seen in thetransport industry: instead of heavysteel and wood construction, lighterand more ergonomic plastics, compositematerials and fire-safe foams and textiles have brought great advantagesto the manufacture of modern trainsand planes, allowing the production of more comfortable seats as well as sleeker designs. This has in turn led to enormous improvements in
The vast set of new and constantly evolvingmaterials in our homes
and offices have given rise to a host of new issues
relating to fire safety.
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performance, comfort and stylewhich we are all able to enjoy.
Technology has made perhaps some of the most astounding leaps in recentyears, with gadgets and appliancesbecoming a part of our everyday lives,in our homes and offices, which wewould never have thought possibleeven just a few years ago. However, weseldom stop to think about how they
are made, or of the safety considerationsthat were involved in their manufacture.Safety is simply taken for granted.In reality, the vast set of new andconstantly evolving electrical and electronic equipment has given rise to a host of new issues related to firesafety. This is because the increaseduse of lighter and more diverse plasticsin the production of these productscan also make them more flammable,
unless appropriate fire safety featuresare used. So, while new materials offer many benefits, they also createan important new problem – they tend to pose a greater fire risk than thematerials they have replaced. That iswhy flame retardants have become anessential component of many productsand are often used to meet Europeansafety standards and laws.
1960s 2010
TELEVISIONS EXTERNAL CASINGS:heavily treated wood which required oilsand polishes to protectthe finish
UPHOLSTERED FURNITURE FILLINGS:uncomfortable and expensive straw, feathers or cotton UPHOLSTERED
FURNITURE FILLINGS:safer, low allergenic foamsand fibers
INSULATION:modern energy efficient buildings with plastic foams and cellulosic materials with high thermal insulation power
INSULATION:porous stone and woodconstruction with hardly any insulation at all
TELEVISIONS EXTERNAL CASINGS:light weight, affordable plastic materials that are cleanedwith the wipe of a cloth
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THE HISTORY OFFLAME RETARDANTSAND REASONS FORTHEIR USESince the discovery of fire, man hasbalanced fire’s utility with its destructivepower with varying degrees of success.Fire prevention methods, including theuse of flame retardants, have beenaround since ancient times. As far backas the Egyptians and the Romans, thechemical compound alum was used insolutions to reduce the flammability ofwood. By the Second World War,ignition-resistant canvas for tents forthe military was produced using atreatment of chlorinated compoundsand metal oxides.
But it was in the 1970s that the development of new and more sophisticated polymers and advancedmaterials took off and with it theincreased need to reduce their combustibility for the protection ofproperty, people and the environment.This is when many of the flame retardants in use today first appeared on the market.
Flame retardants are derived fromnaturally-sourced elements which areincorporated into materials such asplastics, textiles, foams, timber andpaints. They can also be used during
the production process as a chemicalmodification of some plastic materials.Most importantly, they fulfil a vitalfunction: they can delay ignition, slowdown the combustion process, or evenmake the material self-extinguishing.They therefore play a crucial role infire protection, as they not onlyreduce the risk of a fire starting, butalso the risk of the fire spreading - so leaving more time for people toescape. Studies have shown thatescape time is at least 15 times longerwhen flame retardants are used,compared to when they are not.
In practice, this means that when anon-flame-retarded TV set catchesfire, it gives just two minutes escapetime. In contrast the flame-retardedset can provide up to 30 minutesescape time1.
In Europe, the European Commissionhas estimated that there has been a20% reduction in fire deaths as a directresult of the use of flame retardantsover the past 10 years2.
WHAT ARE FLAMERETARDANTS ANDWHERE DO THEY COME FROM?The term ’flame retardant‘ describes a function rather than a chemical
class. In fact, a wide range of differentchemicals act as flame retardants,often applied in combination. Thisvariety is necessary because the materials and products which need to be rendered fire-safe are very different in their nature, their composition – and indeedtheir application.
In all, more than 200 different types offlame retardants exist, which producershave classified according to their majorconstituent elements. The different elements govern their chemical reactionwith fire and so determine their suitabi-lity in different applications. The mostcommon elements used are: bromine,phosphorous, nitrogen, and chlorine.Minerals are also used extensively.
BROMINEBromine, like chlorine, fluorine andiodine, is one of the elements in thechemical group known as halogens.The word halogen derives from Greek,meaning ‘salt-former’, because theseelements are commonly found innature, in the form of natural salts.For example, sodium chloride, or tablesalt, is the most common halogen salt.Bromine is abundant in nature, both in the form of bromide salts, or asorganobromine compounds, which are produced by many types of livingcreatures on land and in the oceans.
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Flame retardants are made up of naturally-sourced elements which are added or appliedas a treatment to materials such as plastics,textiles, foams, timber and paints.
1. Babrauskas V, Harris R, Gann R, Levin B, Lee B, Peacock R, PaaboM, Twilley W, Yoklavich M, and Clark H. Fire Hazard Comparisonof Fire-retarded and Non-Fire-Retarded Products. July 1988. NBSSpecial Publicaiton 749. Fire Measurement and Research Division,Center for Fire Research, U.S. National Bureau of Standards.Gaithersburg, MD.
2. Flame Retardants. DG Environment Video 2000, cited by AEATechnology, January 2001
The most recoverable form of bromineis from soluble salts found in the DeadSea, salt lakes, other inland seas and in “underground” saltwater seas andgeologic formations, deep below theearth’s surface.
A common use of bromine is in making flame retardants. Due to itsunique chemical interaction with thecombustion process, bromine is anextremely efficient element, meaningthat a relatively small amount is needed to achieve the needed fireresistance. Brominated flame retardants are used to protect a widevariety of electrical and electronicequipment from fire, including televisions, computers, radios, stereosystems, fridges and washing machines.
They are also used in the production ofpublic and private modes of transport.In the home, they can be applied tothe foam used to fill upholstered furniture, as well as in carpet backing,curtains and furniture fabrics.
CHLORINEMost people are aware of chlorine usein cleaning products, or as a disinfectantin swimming pools. However, chlorinealso has properties that make itvaluable in the fight against fire.
Chlorine is found primarily as a compo-nent of the salt that is deposited inthe earth, or dissolved in the oceans- about 1.9% of the mass of seawateris chlorine. Even higher concentrations
of chloride are found naturally inunderground brine deposits and otherspecific locations.
Chlorinated paraffins and chlorinatedphosphates are used to prevent a wholerange of materials from catching fire,including leather, paints and coatings,rubbers, textiles, foam fillings for furni-ture and other materials. It is also dueto its chlorine content that polyvi-nylchloride (PVC) has some intrinsicfire-resistant properties.
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INORGANICS AND MINERALSA wide range of inorganic and mineral compounds are used as flameretardants, or as elements of flameretardant systems in combination withbromine, phosphorus or nitrogen.The inorganic compounds include those based on nitrogen (melaminecompounds), graphite (as used in pencils), silica (as in glass and sand) and inorganic phosphates (ammoniumphosphate and polyphosphate).Mineral compounds include certainphosphates, metal oxides, hydroxides,and other metal products (aluminium,zinc, magnesium, molybdenum,boron, antimony).
Some inorganic and mineral compoundscan be used as part of a flame retardantsystem, in combination with otherelements, to achieve fire safety in plastics, foams, natural and man-made textiles, wood and timber products.
PHOSPHORUSThe large majority of the world’sphosphorus is found in mines, many in the south of China. Phosphorusis used to produce liquid and solidorganic or inorganic flame retardants,which are extensively used in polyure-thane foams to make fire resistant furniture, mattresses and thermal insulation materials, in intumescent or fire resistant coatings, as well as
in flexible PVC commonly used in insulation for electric cables. It is alsoapplied in electronics and in high temperature polymers (plastics) usedfor manufacturing switches, connectorsand in certain less flammable polymersused for casings.
NITROGENNitrogen is the largest single constituentof the Earth’s atmosphere and is presentin all living organisms. Nitrogen compounds comprise a relatively smallgroup of flame retardants. Today theirmain applications are in nylons, in polyolefins (a type of hard plastic), inpolyurethane (synthetic) foams, inintumescent coatings (fire resistantpaints), textiles and wallpapers.
HOW SAFE ARE FLAMERETARDANTS?Environmental and human healthconcerns about chemicals, includingflame retardant chemicals, are animportant discussion topic in Europe.The REACH Regulation, which cameinto force in 2008, was designed to address these concerns. The under-lying principle behind REACH is therequirement placed on manufacturersor importers to demonstrate safe usefor human health and the environmentfor all chemical substances placed on the EU market at quantities over 1 tonne/year.
Several flame retardants have alreadybeen rigorously assessed under theprevious regime to REACH, called theExisting Substances Regulations. Thisprocess, involving experts from allmember states, the Commission services, industry and public interestgroups, had identified both substanceswhich were deemed to be acceptablefor marketing and use and otherswhich were restricted due to theirpotential risks.
For example, of the chlorinated phos-phates, one, known as TCEP, was foundto have some unacceptable properties1,whereas others, such as TCPP or TDCP,were deemed as acceptable to use2. Ofthe brominated family, OctaBDE3 andPentaBDE4 are restricted for use, whilethe largest brominated flame retardantby volume, TBBPA,5 was cleared for use.In the inorganics family, boric acid hasbeen found to be unsuitable for use,together with selected boron salts.Other substances in these families aregoing through the REACH registrationprocess. Over the past 20 years, theflame retardants industry has madesignificant improvements in ensuringthat the environmental impacts offlame retardants are controlled andminimised, both in terms of enhancingtheir profile as well as making changesto the way in which they are used.
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The TV sets example
TVs in the US used to be safer thanTVs in Europe, because the formerwere required to comply with higherfire safety standards. This situationchanged in July 2010, with the amendment to standard EN 60065related to safety requirements for electrical and electronic products. Thenew standard requires television setsto be designed in such a way that thechance of ignition and the spread offire is minimised.
Clearly the highest possible level of firesafety is desirable for everyone and theharmonisation of fire safety standardsis an ongoing process.
The UK example
After many years of serious firesinvolving upholstered furniture, in1988 the UK passed legislation requiring upholstered furniture to meeta higher flammability standard, whichrequired both the fillings and covers ofupholstered furniture to be made firesafe. This legislation proved highlyeffective as older furniture was graduallyreplaced by newer, safer furniture. As a result of this legislation, there hasbeen a demonstrable reduction in thenumber of fatal accidents, injuries and property damage.
The results of a 2009 study, commis-sioned by the UK Department ofBusiness, Innovation and Skills, haveshown that the products covered bythe UK Furnishings and Furniture
Regulations (FFR) account for 54 fewerdeaths per year, 780 fewer non-fatalcasualties per year and 1,065 fewerfires per year6.
Thanks to these regulations, since1988, British consumers have benefitedfrom having the highest levels of firesafety protection for furniture in theworld. While many countries have firesafety standards in place, these arerarely the same in all countries. WithinEurope, for example, regulations forfurniture vary considerably betweencountries and applications.
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Number of fires – before and after the UKFurniture Fire Safety Regulations
During the past few decades, consumer fire safety standards have improved gradually, and as a result, flame retardants havebecome a vital component of a vast range of products. They help to achieve compliance with mandatory fire safety standards,and it is not unusual to find responsible manufacturers using them voluntarily in fields not yet covered by regulations.
FIRE SAFETY STANDARDS
1. http://tcsweb3.jrc.it/documents/Existing-Chemicals/RISK_ASSESSMENT/REPORT/tcepreport068.pdf
2. http://tcsweb3.jrc.it/documents/Existing-Chemicals/RISK_ASSESSMENT/REPORT/tcppreport425.pdf
3. http://tcsweb3.jrc.it/documents/Existing-Chemicals/RISK_ASSESSMENT/REPORT/octareport014.pdf
4. http://tcsweb3.jrc.it/documents/Existing-Chemicals/RISK_ASSESSMENT/REPORT/penta_bdpereport015.pdf
5. http://ecb.jrc.ec.europa.eu/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/OJ_RECOMMENDATION/ojrec79947.pdf
6 .A statistical report to investigate the effectiveness of theFurniture and Furnishings (Fire) (Safety) Regulations 1988,December 2009 (http://www.bis.gov.uk/files/file54041.pdf)
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Flame retardants have allowed engineers to consider new materials, which would otherwise have
been avoided for their high fire risks
02 ELECTRONICSFrom static and bulky to portable,light and energy efficient
In recent years, probably no other type of producthas evolved and improved more than electrical andelectronic goods. Today, we take for granted beingable to talk on the phone while we are walking alongthe street, or watching a film on a computer duringa long train ride. Key to this constant evolution intechnology has been the ability to switch fromheavy and costly materials, to lighter and moreenergy efficient ones.
So where do flame retardants come in?The innovations that have become anatural part of our daily lives havebeen accompanied by new issues offire safety. Flame retardants have allowed engineers to consider newmaterials to produce televisions,computers, laptops or householdappliances, which would otherwise not have been possible because of those materials’ high fire risks.Thanks to flame retardants, the risk of these materials now catching fire is much reduced.
Originally, plastic components were onlya tiny percentage of the parts used inelectronics. Today, they are part ofalmost every component in a computer,as well as in most electrical equipmentand electronic appliances. However,because of the risk posed by internalelectrical short circuits, heat releaseduring use and the potential for ignitionfrom external sources such as candles, itis extremely important to incorporateflame retardants into the plastic if it isbeing used anywhere near an elecricalcurrent as well as other sources of heator ignition.
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TV sets have undergone an extraordinary and rapid transfor-mation since their early days.With every year, enormous numbers of new models appearwith seemingly ever-increasing frequency.
The first commercial television setsdate back to the 1950s in the US andslightly later in Europe. They weresemi-mechanical and had huge bodies,but the screens were tiny. As the yearspassed, the screen remained small, butthe size of the TV sets as a whole
became increasingly more compact.As TVs became more affordable, theirpopularity increased.
The biggest developments in televisionstook place in the late 60s and early 70s.Design-wise, sets started to resemblemore the TVs we would recognisetoday. Whereas previously the casing ofTVs was a mixture of wood and metal,manufacturers started producing andusing lighter, more affordable and moremouldable plastic materials. Initiallythese were only used to make the televisions’ back panels, but gradually
ELECTRONICS
1950s 1970s
From static and bulky to light and energy efficient
An LCD TV contains an average of 8.4Kg of plastics,
which, without the applicationof flame retardants, would be
equivalent to roughly 6 litresof gasoline in terms of potential heat release.
TELEVISION
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their use spread to the sides and finallythe front of the TV set.
The ability to mould plastics into different shapes not only contributedtowards improvements in style, it alsobrought benefits to TVs’ cooling sys-tems, as well as a significant reductionin energy consumption at the stage ofmanufacture. It was also at this timethat colour TVs started to appear.
Since then, television sets have rapidlybecome an everyday item in people’shomes, as, thanks in part to lower
production costs, they have becomeaffordable for almost everyone. Overthe years, ever slimmer, sleeker andhigher quality models have emerged.
An LCD TV contains an average of8.4Kg of plastics, which, without theapplication of flame retardants, wouldbe equivalent to roughly 6 litres ofgasoline in terms of potential heatrelease. In spite of this, there is very little for consumers to be concernedabout, as the use of flame retardantsdramatically reduces a TV’s flamma-bility. Blending flame retardants into
the plastic mix used for TV casingsensures that the plastic will burn at amuch slower rate - or will not catch fireat all - when exposed to internal (suchas an electrical fault) or external (suchas a candle light) sources of heat.The internal components of TVs havealso undergone significant changes,particularly the electronic components.These are also protected by flameretardants, incorporated in the circuitboards as well as in the internal and external wiring.
1990s 2010
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INTEGRATED CIRCUITS Small transistors placed on silicon chips,called semi conductors,helped to increase thespeed and efficiency ofcomputers and allowedthe transmission ofinformation from onecomputer to another.
ELECTRONICSFrom static and bulky to light and energy efficient
COMPUTER
Like televisions, computers have evolved enormously since the days –not so long ago – when they wereenormous machines that took up an entire suite of rooms in officebuildings.
As in the case of televisions, flameretardants are used in the casings of computers and laptops, as well asin their various plastic components.They are also applied to the electronicchip packaging, in printed circuitboards and in the materials surrounding the batteries.
Another important application offlame retardants is in the insulation ofcabling. Considering the jungle of electrical cables to be found in most ofour homes today, this application hasbecome crucial to safety. 50 years ago,cable insulation was usually made oftextiles, which not only created a riskof exposed wires, but could also affecta wire’s electrical performance.Since then, strong and durable plasticshave been developed and used as insulation material, which also offervastly improved electrical properties.This has been particularly important
VACUUM TUBESused machine language for computing and could only make one calculation at a time.
1940-50s 1970sTRANSISTORS made computerssmaller and cheaper as well as more energy efficient.
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COMPUTERS OF THE FUTUREThe current trend is to exploit the world’s interconnected networks,each comprising thousandsof PCs, so that a multitudeof computer processes cantake place simultaneously.
MICROPROCESSORS The microprocessor ismade up of thousands of integrated circuitsplaced onto a siliconchip. It is the single most vital component of the computers we use today. It allowscomputers to carry outmillions of calculationsevery second.
IN NUMBERS
for cables which transfer data between interfacing devices, such as between a computer and a printer, which require particularly efficient plastics.
The size of computers has also reduceddramatically over the years, alongsidean insatiable demand for portable devices which allow us to have a widevariety of applications and internetaccess at our fingertips. The past fewyears have seen an increased trend forhandy laptops, net-books and personaldigital assistants, almost to the point of
rendering the desktop redundant.However, this miniaturisation of computers, as well as ever increasingcapacity and level of performance, hasled to an increase in the concentrationof heat-generating components contained by these devices, so making flame retardants an important safety aspect.
5,000 kg, 500 km wires32 Kb
7.5 kg128 Kb
<3 kg and wireless connections500 Gb = 500,000,000 Kb!
Ever increasing capacity and level of performancehave also led to an increase in the amount of
heat generated, which has made the use of flame retardants even more crucial.
1970s-TODAY 2010 & BEYOND
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ELECTRONICSFrom static and bulky to light and energy efficient
‘Quick-wash’, ‘easy-iron’, ‘delicates andwool’, ‘economy’, ‘sports equipment’ ...these are just some of the optionsavailable when we load our washingmachines today. It hasn’t always beenthat way.
Early machines had mechanical timerswith motors which ran at a constantspeed throughout the cycle. If youwished to shorten parts of the programme, you would need to do so by manually advancing the controldial. By the late 1980s, however,electronic timers started to replacetheir mechanical versions, introducing
WASHING MACHINE
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greater variation. It was not until themid 1990s, however, that upmarketmachines started to incorporate theelectronic micro-controllers commonlypresent in the machines we use today,and which enable us to choose from sucha wide range of washing programmes.
A very significant development forwashing machines in the past 25 yearswas the introduction of an electronicsystem for programming the washcycle. This was accompanied by areduction in the amount of water andenergy needed for each cycle, resultingin important energy savings.
From a fire safety perspective, however,plastic, heat and electricity are not adesirable combination! That is why, inaddition to their application in plasticcasings and in plastic cables, one of the main uses of flame retardants inwashing machines is in the electronicboards. It is thanks to their flameretardant properties that the electroniccomponents which regulate the complexprogramming of modern washingmachines can do their work safely.
It is thanks to flame retardants that the electronic components which regulate the complex programming of modern washing machines can operate safely.
2010
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The application of flame retardants in different natural andsynthetic filling materials and textile fibres plays a key role
in helping to meet regulations across many EU countries.
03 FURNISHINGFrom impractical to functional
Our lifestyles have undergone significant changesover the past 50 years, with people moving home and changing jobs far more frequently than before.Socio-economic developments and improved livingstandards have resulted in an increase in the demandfor equal levels of comfort across the social spectrum.
Home and office furniture have beenadapted to fit modern life’s new requirements. Over the years, thanks to the emergence of new materials, ithas become lighter, more ergonomic,more practical, and affordable for all.
Until the 1940s, textiles were madefrom natural fibres, such as cotton,wool and silk. However, not only werethese materials costly, but their supplywas not sufficient to respond to risingnew demands. When nylon came onto the scene, followed by polyesterin the 50s and polypropylene in the60s, it represented a revolution in thetextile world. These new fibres offeredenormous advantages over naturalfibres, including increased durability,improved hygiene, greater versatility –
all in addition to lower productioncosts. The introduction of these newmaterials has therefore helped toensure that everyone can continue to enjoy similar levels of comfort at an affordable price.
The fire risk involved in upholsteredfurniture is generally recognised andunderstood. In fact, many EU countrieshave now put strict standards in placethat ensure the fire safety of furnitureand fittings in public places such astheatres, museums and hospitals.
The application of flame retardants indifferent natural and synthetic fillingmaterials and textile fibres plays a keyrole in ensuring that these fire safetystandards are met.
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FURNISHINGFrom impractical to functional
UPHOLSTERED FURNITURE Some sofa cushions forever need to beplumped up; others pop back intoshape immediately after you get upfrom sitting on them. The difference islargely down to the material used tofill their casing. The cushions thatretain their shapes are very likely tocontain polyurethane or polyesterfoam, which is resilient, flexible, easyto manipulate and which can be moulded or shaped to meet the mostcomplex upholstery styles and designs.Many sofas, armchairs and differentkinds of seating rely on foams as fillingmaterials. Most importantly, the newfoams have not only given endlessopportunities to shape furniture according to different tastes, but are also addressing health concerns.
Foam has great advantages overfeathers for cushions and pillows. Thisis not only because some people are
allergic to feathers, or the dust thatthey generate, but also because, inthe absence of an alternative, thedemand for feathers would be sogreat that that it could raiseissues of availability as well asconcern for the well-being of the animals providing them.
BED MATTRESSESBed mattresses are a perfect exampleof the enormous improvements incomfort and practicality brought about by the use of new materials.
As early as the Neolithic period, peoplebegan to care about the materials theyslept on: primitive populations coveredtheir stone beds with animal skins,leaves, grasses and straws, while in theRenaissance, straws, feathers and leaveswere stuffed inside long, thin poucheswhich were made of canvas, silks orvelvets. It was the 18th century,
however, which saw the arrival of new mattresses with the same basiccharacteristics as today’s.
THE PRINCESS AND THE PEAWhen luxury still couldn’t afford you a comfortable night’s sleep
1800sHorsehair and wool filling
1950sWool filling
2010Foam filling
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Back then, mattress fillings includedcotton and wool, as well as coconutfibers and horsehair. However, thesekinds of mattresses were only availableto a very few who could afford them.Most people continued sleeping onmattresses stuffed with straw, or thistledown, or even on straw pileddirectly onto the floor.
It was in the 1950s that the advantagesof polyurethane foams became apparent.Thanks to their cost-effectiveness,these started to be produced in higherquantities and their use as fillings formattresses became more widespread.Today, mattresses still contain manydifferent kinds of both natural and synthetic fillings, including coir, sisal,lamb’s wool, cotton, memory foam,artificial latex or polyurethane, and
these are almost always used in combination. It is largely thanks to theemergence of synthetic materials thatmodern beds are more comfortable,better for the body and more hygienic- all at an affordable price.
Foam fillings have also significantlyimproved the lives of those forced tospend most of their time lying down.They have allowed the development of adjustable beds, which are widelyused in hospitals. The flexibility of thematerial used in the mattress makesit possible for it to bend into differentchosen positions. Adjustable andmemory foam mattresses also offerhigh therapeutic benefits as they simply conform to the position of the body.
ALTERNATING PRESSURE MATTRESSAlternating pressure pad systems insidesome mattresses help to prevent bedsoresand relieve painful pressure points. The system is operated by a quiet pump, whichinflates 130 individual bubble cells insidean artificial foam filling, so easing thepressure on contact points and preventingulcers from developing.
MEMORY FOAMThe malleable properties of foam help torelieve pressure points, as the mattressconforms to the sleeping position of the person lying on it.
Many of the materials used inmattress fillings, however, bothmodern and traditional, are highlyflammable: statistics show thatlethal domestic fires frequentlystart either in beds or sofas, oftenfrom burning cigarettes, lit candlesor children playing with matches.The combination of air and fuelcontained in the foams usedin mattresses is particularly conducive to the spread of fire.This is why the fire resistance of fillings and textiles used in furniture and bedding isabsolutely essential.
ADJUSTABLE MATTRESSSpecially designed bed mattresses can adapt themselves to all the different positions of the adjustable bed.
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CURTAINS AND CARPETSToday’s home furnishing materials areconstantly adapted to fit our new,busier lifestyles. The development ofnylon and polyester – replacing silk,wool and cotton – have also broughtsignificant practical advantages to thetextiles used in home furnishings.Due to their special properties, theinclusion of these materials in themanufacture of curtains, carpets andupholstery has made it much easier tokeep them clean and has significantlyreduced their wear and tear, as well as
helping to guard against the insects,fungi and mildew which often attack natural fibres.
In addition, certain natural fibres represent a high risk in the event of afire. If not fire treated, they have thepotential to burn vigorously. They canalso continue to smoulder, causing firesto restart or to propagate. Textiles usedfor curtains and blinds, whether naturalor synthetic, pose a particularly highrisk because they are hung verticallyand so easily catch fire, after which the flame travels more rapidly up the material.
Applying flame retardants to materialsof all levels of flammability - whethercotton, wool or polyester - helps to reduce dramatically the rate atwhich these textiles burn and can also prevent fire from spreading. Flameretardants are either incorporated into the fibres, added to the textile at the same time as colouring and finishing, or applied to the finishedfabric. Their effect is crucial: they caneither abate the fire completely, act asa barrier between the flame and thefoam inside the furnishing, or slowdown the spread of the flame to the rest of the textile.
LA DAME À LA LICORNEMoth caterpillars are a serious pest of tapestries, as they enjoy feeding on wool.
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Today we can choose between a wholerange of textile materials when furnishingour homes, and flame retardants can ensure that they are all equally fire safe.
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Flame retardants have been an invisible but essential elementin the innovation of materials used in the construction
of public buildings and homes, contributing to a substantial improvement in our quality of life.
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04 BUILDINGSFrom cold and creakyto comfortable and cosy
A whole range of factors, including socio-economicdevelopments, technological innovation, new styleand design requirements and a growing emphasison environmental concerns, have contributed to an ongoing evolution in the way our buildings are constructed.
A growing trend towards urbanisation,coupled with the rise of affordablemodern electrical equipment for the home, has led to a greater concentration of city dwellers, eachwith rising expectations of what theirhomes should provide, and whichmodern conveniences they shouldcontain. In addition, increasingly
more complex buildings have beenconstructed which require a higherlevel of insulation.
Thanks to constant innovations in insulation, wiring and structural elements, today’s new buildings aremore energy efficient, more comfor-table, safer and healthier than ever
before. New materials have also openedup a much wide range of possibilitiesin the scope of design. In the past,buildings were mostly made of stone,brick, plaster and wood. Today’s plasticinsulation materials, composites, metalsand glass have brought far greater versatility to the conceptual and creative side of construction.
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BUILDINGSFrom cold and creakyto cool and cosy
CABLES AND ELECTRICINSTALLATIONSThe technological revolution, startingin the second half of the 19th centuryand continuing at ever greater pacetoday, has resulted in a huge surge inpower requirements for public buildingsand private homes. New technologies,such as phones, televisions, washingmachines, fridges or computers allneed electrical connections. The increasing need for more power is also due to elevators, heating systems and other structural featuresin modern buildings. This growth in
electric installations has brought withit a greater risk of fire. The sheervolume of cabling in any modern building poses an enormous risk due to the flammability of the insulatingmaterial, the potential for short circuits from overheating and electrical faults.
As electricity is carried from the generating station to the building itsupplies, the power is gradually redu-ced. The initial levels are very high,however, which is why the the wireswhich are just leaving the plant haveto be thick – the further away from
1950sSwitch (porcelain)
1950sFuse panel
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Components in switches,sockets and fuse boxes are
now made out of plastics,widely replacing porcelainwhich is fragile, expensive,and requires high levels ofenergy during manufacture.
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the generating source, the thinner thewires can become.
Inside a building, the large amount of electrical or communication cablesextending out to different rooms aregenerally hidden out of view behindthe walls. These cables are all thicklybunched together in columns, someti-mes running vertically from one floorto another and so pose a particularlyhigh fire risk. In addition, since theyare not all required to comply with thesame flammability standards, if onetype of wire causes a fire, it can affectall of them. Moreover, the fact that
they are lodged inside the walls of thebuilding makes it even more importantto ensure their safety, as they are noteasily accessible for safety checks and maintenance.
It is essential, therefore, that wires arewell protected from any chance of their catching fire. Cables are thereforetypically coated with insulating plasticmaterials that contain flame retardantsto prevent any spark or flame fromspreading along the jacketing of electrical or communication cables.
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STRUCTURAL INSULATIONWhen energy supply started to becomewidely available, people were able toheat their homes easily and affordably,so insulating a house became lessimportant than it had been previously.Today, insulation has again become apriority in homes, offices and publicbuildings due to the increasing need to conserve energy for environmentalreasons and rising costs. From the1970s onwards insulation standardsstarted to see real improvements.The main purpose of insulation is tolimit the transfer of energy between
the inside and outside of a building.Thermal resistance, or the R-value of amaterial, is important as it measures theinsulation capacity of the material. Thehigher the R-value, the more effectivethe material. For most insulating materials, the value varies between R-0 to R-10.
Various types of insulating materials are in use today, including expandedand extruded polystyrene foams, rigidpolyurethane foam, glass wool, rockwool or cellulosic fibres. Due to theircombination of performance and relatively low cost, polystyrene and polyurethane foam panels rank
amongst the most popular choices for insulation.
Insulation materials and rigid panelsplay a critical role in efforts made bygovernments to meet global, regionaland national energy efficiency targets.Polystyrene insulation foams, for example, are crucial in ensuring theimplementation of the EU Directive on energy performance in buildings(2002/91/EC). However, like the foamsused in upholstered furniture, building insulation foams also carry the risk of being highly flammable.
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Expanded and extruded polystyrene foam board insulationconsists of large sheets of plastic foam and can be used in mostareas of a building. It is inserted between studs on interiorwalls as well as over concrete walls to insulate basements. It isalso used to insulate ceilings and roofs. However, the role offlame retardants is crucial at the construction stage, wherethe highly flammable insulation materials are most exposedto the risk of fire. In fact, most insurance companies willonly provide insurance at construction sites if these are protected through the use of flame retardants.
Expanded polystyrenefoam board insulation
Polyurethane foam panels are used toinsulate walls and ceilings against sound,which is particularly important in placessuch as nightclubs and recording studios.Their treatment with flame retardantshelps to safeguard against fire-related accidents.
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FOAM BOARD INSULATION
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To reduce the risk of fires and provide enoughtime to evacuate a building in the event of a
fire, manufacturers and fire safety authoritieshave promoted the use of flame retardants
and low combustion building materials.
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STRUCTURAL ELEMENTS‘Intumescence’ means a ‘swelling up’or ‘expansion’. In a building context,an intumescent product is one whichexpands when in contact with heat.The product is typically made of acombination of additives which reactchemically when they reach a certaintemperature. They are available aspaints and coatings which are appliedto protect a whole variety of materials,including steel structures, metal sheets,wood , plaster and concrete. Flameretardants are a major component inthe formulation of intumescent paints,coatings, sealants and mastics.
When they come in contact with aflame, intumescent coatings expand by
several times their original thickness,forming a thick, insulating non flammable foam.
One of the most common uses of intumescent coatings is in steelwork.When structural steelwork reaches a critical temperature, it can lose itsload bearing capability and buckle orcollapse, with drastic consequences for the stability of the building it is supporting. To prevent this, intumescentcoatings are applied to the steel. In theevent of a fire, the foam formed by instumescent coatings insulates themetal structure from the heat.
To reduce the risk of fires and provideenough time to evacuate a building in the event of a fire, manufacturers
and fire safety authorities have promoted the use of ignition resistantand low combustion building materials.Flame retardants are used in buildingmaterials because not only do theyraise the threshold temperature atwhich a material ignites, but they also reduce the rate at which it burns,diminish flame spread and in somecases abate smoke.
Flame retardants are critical to meetingregulatory requirements for fire safetyin public buildings, and their use helpsto ensure that cinemas, theatres andhospitals are safe from the risk of fire.
FIRE RETARDANT WOOD
As a building material, wood is one of the most versatile, renewable and easily workable products.However, wood has always been associated with fire.Flame retardants have ensured that we can continueto benefit from wood’s qualities, while being reassuredthat the risk of fire is minimised. Indeed,also due to the fact that it can now betreated with flame retardants, wood hasrecently enjoyed renewed popularity,especially in Europe, in the construc-tion and decoration of our homes.
Flame retardants are used in solidwood panelling, structural woodproducts, wood-based panelsand wood flooring.
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Due to the flammability of plastics, composite materials, foams and textiles, their use is dependent on ensuring that they are fire safe. In particular, when they are used in public transport,
public authorities and private operators have a high degree of responsibility to guarantee the maximum
possible level of safety for passengers.
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05 TRANSPORTFrom slow to swift and from heavy to light
An area of our lives which has been transformedby the technological advances of the past centuryis that of mass transport. Today, we can flyaround the world in the time it would have takenour grandparents to travel from London to Paris.Travel has become much faster, easier, safer,more affordable and more comfortable for all.
This has largely been made possiblethanks to the emergence of new,lighter and technologically advancedmaterials such as carbon and glassfibres, composite materials and aluminium, as well as malleable,resistant and easily workable plastics,foams and new types of textiles. Thesematerials have particular propertieswhich not only make them ideally suited for specific and increasinglymodern functions, but also highlyadaptable and economical. As a result,they are increasingly used in themechanical, structural and decorative
parts of our trains, planes, boats,trucks and automobiles.
By using these new materials, thestructure and weight of transport vehicles have also become much lighter, helping to reduce the amountof fuel needed and thereby leading toimproved energy and cost efficiency.The replacement of metals with plastics has also resulted in lowermanufacturing costs: a single plasticmould can be made and used (and re-used) in one go, instead of assemblingseveral different component parts. This
has made manufacturing processes less labour-intensive.
Due to the flammability of plastics,composite materials, foams and textiles,however, their use is dependent onensuring that they are fire safe. In particular, when they are used in public transport, public authorities andprivate operators have a high degree of responsibility to guarantee themaximum possible level of safety for passengers.
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TRANSPORTFrom slow to swift and from heavy to light
AIRPLANES
The introduction of jet-poweredtransport in 1952 heralded the beginning of a revolution in domesticand international air transportationthat has accompanied the developmentand refinement of the modern airplane.Today, air travel’s previously unimaginable high speed, excellentsafety record and affordability havetransformed the accessibility of far-away destinations and allowedmany more people to experience places and cultures that in the pastwere only available to the affluent.
The emergence of new materials hasallowed engineers to develop aircraftwhich are lighter, more energy efficientand far safer than ever before. Flameretardants play a crucial role in ensuringthese materials can be used safely,thereby saving thousands of lives.
Different types of innovative plastics arenow present in almost every componentof the interior of any modern commercial aircraft. These range frompolymers used to make overhead compartments, flexible polyurethaneseat fillings and track covers to synthetic textile carpets and thermo-plastic layers covering the sidewallpanels. These readily processed plasticshave also helped to provide greaterflexibility of aircraft design, allowingsofter lines and more aesthetically pleasing curves in a plane’s interior features.
But the use of these potentially flammable materials in aircraft makesthe use of flame retardants more important than ever before.
Aircraft contain an enormous quantityof electrical and electronic cables, whichare required to transmit informationbetween the plane and the ground, or
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within the plane itself, from the cockpitto the motors and internal mechanics,or simply to the cabin. If any systemcomponent catches fire, the resultingflames could spread rapidly, with potentially disastrous consequences,especially considering the difficulty ofevacuating a plane. This makes itabsolutely essential that aircraft cablesand other components are assembledwith fire safety in mind, including theuse of materials protected by flameretardants.
The majority of the vertical and ceilingpanels in an aircraft are covered withthermoplastic films, often printed in a variety of patterns and colours andembossed in a wide selection of textures and gloss levels. However,these products make the need for fireprotection all the greater.
Composites – materials that are combinations of two or more organic
or inorganic components – are one ofthe most important materials developedfor aviation since the use of aluminiumin the 1920s. Composites’ great value is that they are both lightweight andstrong. They are used, therefore, for theoutside structure of a plane to lower itsweight, thereby reducing substantiallythe amount of fuel burnt on any flight.Due to their strength and extreme versatility, a specific composite, glass-fibre reinforced plastic, is becomingmore popular in aeronautical design.
International aviation regulations dictatefire safety standards that are probablystricter than for any other mode oftransport today. Aircraft manufacturersare increasingly able to use plastics,polymers and composites in aircraft fittings, equipment and structuresbecause these materials can be madeignition resistant.
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materials
Aircraft manufacturers areincreasingly able to use plastics,
polymers and composites inaircraft fittings, equipment and structures because these
materials can be made ignition resistant.
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TRANSPORTFrom slow to swift and from heavy to light
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TRAINS
New materials have transformed the way we travel by train. Today,passengers expect much higher levels ofcomfort than they did when train travelwas simply a way to get from A to B.Train manufacturers therefore started to develop new materials to improveconditions inside train carriages.
From the 1950s onwards, the use of polyurethane foams as fillings in passenger seats and synthetic fibres ascovers, have made journeys significantlymore comfortable. Wood was graduallyreplaced with durable, affordable andmalleable plastics to make up the
panelling and surfaces of the train’sinterior, whether walls, floors or ceilings.These materials also have the hugeadvantage of being easier to maintain, reducing wear and tear andhelping to keep the train looking clean and fresh.
The possibility of accidents caused bycareless handling of objects such as
1960s
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Curtains, seat covers and fillings, vertical and horizontalpanelling are all rendered firesafe by the application of flame retardants.
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matches and lighters, not to mentionelectrical faults or breakdowns in heating systems, have made railwaysand trains subject to very strict fireregulations. Flame retardants have allowed manufacturers to make full use of available new materials whileensuring that these materials conformto the required fire standards.
Flame retardants have allowed manufacturersto make full use of available new materials
while ensuring that these materials conform to the required fire standards.
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Weight is not an issuefor an average passengertrain, but it is crucial forhigh speed trains, whichmust use the most lightweight materials in their manufacture to realise their speedpotential. TR
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CARS
In the 1950s, the average weight of acar was 1,680kg. Today, the averageweight has fallen to around 1,100 Kg.In a modern car, its frame and body arebuilt as a single unit, rather than on aframe. In addition, new, lighter materialsare being used in the manufacture of acar’s external as well as internal parts.
Among the benefits plastics havebrought to car bodies is their shock-absorbing properties. The use of plasticsin car bumpers, for example, has notonly helped to reduce the physicalimpact of a collision, it has also reducedany ensuing financial impact from
having to repair surface damage causedto the vehicle.
Recycled plastics are now also exten-sively used in the internal structures of a modern car. Replacing metal hasbrought considerable advantages including lack of corrosion, resistance to minor shocks, as well as improvedaerodynamics.
New composite materials are alsoincreasingly used in areas that are not very visible. It quickly becomesclear, though, why their function is sovaluable. Composites are particularlyimportant in parts found under the bonnet or dashboard, which are close
to the heat of the engine, or whichtransmit electrical information and cantherefore generate high levels of heat.Examples include high amperage wireand cable jacketing, electric and electronic equipment, battery cases and trays, components of the stereosystem, GPS and other computer systems. Plastics used in these applications generally contain flame retardants.
Car interiors have also undergone major changes over the years, with new features being incorporated notonly in the instrument panel, but for a variety of different practical and aesthetic purposes.
TRANSPORTFrom slow to swift and from heavy to light
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Plastics had become popular in carinteriors by the 1960s, but as theiradvantages became increasingly evident, their use became more frequent. Gradually, newer and higherquality types of plastic were created,making cars lighter and more efficient.
Flexible and semi-flexible polyurethanefoams are now used extensively insidecars - in seats, headrests, armrests, roofliners, dashboards and instrumentpanels. Used in insulation panels, theyhave also helped to improve soundslevels inside the car as you drive,reducing noise from the engine and thefriction between the tyres and the road.Fire safety requirements for cars are
lower than for public transport.However, the fact that the materialsused in a car are subject to a hugeamount of thermal stress on a dailybasis makes their use practically inconceivable without the application of flame retardants.
As in so many other areas of our lives,flame retardants play an indispensiblerole in helping to ensure that we canenjoy the highest level of fire safetypossible while moving from one place to another.
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The fact that the materials used in a car are subject to ahuge amount of thermal stresson a daily basis makes their use practically inconceivablewithout the application of flame retardants.
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06 IN DETAILHow do flame retardants work?
There are many different flame retardants, but they all work in only a few distinct ways. While some flameretardants do the job on their own, others are used as“synergists”, acting to increase the effect of other typesof flame retardants. This variety of products is necessarydue to the fact that the materials to be rendered fire safeare very different in nature and composition. For example,plastics have a wide range of physico-chemical propertiesand their behaviour during combustion tends to differ.Therefore, flame retardants need to be appropriately matched to each different type of plastic in order for it to retain key functionalities.
EXOTHERMIC RADICAL CHAIN REACTIONSFree H. and OH. radicals break molecules down andenable reaction with O2
PYROLYSIS
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FLAME RETARDANTS ACT IN ONE OR SEVERAL KEY WAYS TO STOP THE BURNING PROCESS.
They act to:
• Disrupt the exothermic radical chain reactions of combustion (capture the H. and OH. high-energy free radicals)
• Physically insulate the fuel from the heat source(by production of a fire resisting “char” or glassy layer on surface, thereby limiting the process of pyrolysis)
• Dilute the flammable gases and concentration of oxygen in the flame formation zone (by emitting water, nitrogen or other inert gases)
To understand how flame retardantswork it is useful to have an idea ofthe way materials burn.
Solid materials do not burn on directcontact with a flame: they must befirst decomposed by heat (pyrolysis) to release flammable gases. Visible flames appear when these combustiblegases are mixed with the oxygen (O2)in the air in the presence of high-energy free radicals and hundreds ofexothermic radical chain reactions canstart. If the conditions for combustionare not attained, the material will
simply slowly smoulder and often self extinguish. The material remainingafter the polymer has released flammable gases is a stable carbonaceous “char”.
The heat generated by the exothermic radical chain reactions breaks down(pyrolysis) long-chain solid moleculesinto combustible gases, which are in factsmaller short-chain molecules. The firebecomes a self-sustaining chemical reaction when the combustion of theflammable gases supplies enough energyto the material that released them, to
the point that the decomposition (pyrolysis) can continue and supplyenough fresh combustible.
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HALOGENATED FLAME RETARDANTS AND THEIR SYNERGISTSHalogenated flame retardants or halogenated plastics will act essentiallyin the gas phase, by emitting lowenergy radicals such as Br., Cl. or F..These will substitute high-energy freeradicals (H. and OH.) in the gas phase,quenching the exothermic radicalchain reactions which lead to the flameformation. The absence or significantreduction of energy release averts orconsiderably slows down the burningprocess, thus preventing the fire cyclefrom establishing or sustaining itself.
The effectiveness of halogenated flameretardants depends on the quantity ofhalogen atoms they contain as well as,crucially, on the range of temperaturesover which these halogens are released.Chlorine is for example released over a wider range of temperatures thanbromine, which influences its concen-tration within the combustion zone.
For example, bromine-based FRs arediverse in their chemistry and have abroad range of applications. Many different bromine-containing flame
retardants have been developed, withbromine atoms bound into differentorganic molecules. These offer variousproperties, depending on how the bro-mine is bound into the flame retardantmolecule (aliphatically, aromatically),and on the ways in which the flameretardant molecule interacts with different plastics. Different specific brominated compounds can be addedto or chemically bound into differentplastics without seriously affectingtheir properties (flexibility, durability,colour …). Thus, the various brominatedproducts available offer high flameretardancy solutions for the most commonly used plastics currently onthe market and in most of these plastics’ applications.
The addition of metallic compoundssuch as zinc or antimony oxides willenhance their efficiency, by allowingthe formation of highly efficient transition species, so-called metal oxohalides. For example, while antimony trioxide (Sb2O3) does nothave flame retarding properties on itsown, it is an effective synergist forhalogenated flame retardants or halogenated polymers, such as PVC.
It acts as a catalyst, facilitating thebreakdown of halogenated flame retardants into active molecules.
PHOSPHOROUS FLAME RETARDANTSPhosphorus-containing flameretardants act in the solid phase,when heated phosphorous compoundsrelease a polymeric form of phosphoricacid. This acid causes the material tochar, forming a glassy layer of carbon,and thus inhibiting the “pyrolysis”process which supplies fuel to theflame. The char plays very specific rolesin the flame retardant process. It actsas a two-way barrier, both hinderingthe passage of the combustible gasestowards the flame and shielding thepolymer from the energy (heat) supply.Furthermore, this mode of action significantly diminishes the amount offuel produced, because char (carbon),rather than combustible gases, is formed.
Certain products contain both phos-phorus and chlorine or nitrogen, thuscombining the different flame retardingmechanisms of these elements.Additive phosphorus-containing flameretardants can simply be mixed into
IN DETAILHow do flame retardants work?
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the plastics and are consequentlyincorporated in the material.Alternatively, in cases where reactivephosphorous compounds are used,they can be chemically bound into the plastic molecules during polymerisation.
A wide range of different phosphorus-based flame retardants are available,from the simplest elemental forms tomore complex organic phosphorouscompounds. Certain products containphosphorus as well as chlorine or nitrogen, thus combining the differentflame retarding mechanisms of these elements.
NITROGEN FLAME RETARDANTSIn the current state of knowledge,nitrogen containing flame retardants are thought to interact in several ways with the fire cycle:
Enhancing the formation of cross-linked molecular structures in the treated material. These relatively stable compounds at high temper-atures inhibit the pyrolysis of the polymer to flammable gases (fuel).
Release of inert nitrogen gases whichdilute the fuel / oxygen mix thus preventing the radicals chain reactions from taking place in thecombustion zone.
Nitrogen is known to demonstratesignificant synergistic effects withphosphorus by mutually reinforcingtheir functions. Some flame retardants, such as melamine polyphosphates, have the two elements in their structure.
To fulfil their purpose, nitrogen basedflame retardants are often used inconjunction with others, in particularphosphorus-based flame retardants.Melamine-based products are the mostwidely used type of nitrogen flameretardant today, and applications includefurniture foams, insulation foams andE&E applications.
METAL HYDRATESA wide range of different inorganic compounds, such as metal hydrates,are used as flame retardants, or as elements of flame retardant systems in combination with bromine, phospho-rus or nitrogen flame retardants.
They interfere with the combustionthrough three main physical processes:
Energy absorption through endothermic decomposition contributing to the slowing down of the pyrolysis process.
Release of inert gases, such as water,which dilute the fuel / oxygen mix,thus preventing the exothermic radicalreactions from taking place in the combustion zone.
Production of a non-flammable andresistant layer on the surface of thematerial, reducing the release of flammable gases by the polymer andthe energy transfer to the polymer,which limits pyrolysis.
Due to the relatively low efficiency ofthese mechanisms, the products oftenhave to be used in relatively largeconcentrations, or in combination withother types of flame retardants.
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European Flame Retardants AssociationAvenue E. van Nieuwenhuyse 4 bte. 2B-1160 [email protected]
