Tag Archives: fire

Artificial intelligence for tomorrow’s firefighters

Brand i hus

Artificial Intelligence is more than SIRI on your iPhone and computers that can win at Jeopardy. A project where artificial intelligence assists firefighters during a call-out is running in the USA, and offers huge potential.

A firefighter enters a burning building. In addition to his fire-resistant clothing, boots, gloves and helmet, he also has a head-up-display (HUD), which presents key data in his field of vision. Moreover, his clothing is fitted with various sensors that feed the artificial intelligence that follows the firefighter with the firefighter’s position, temperature data, toxic gases and other hazard warnings. The artificial intelligence analyses the data, simultaneously collecting information from different sensors in the building and from databases with technical drawings of the structure. Based on all the data, the artificial intelligence sends instructions to the firefighter via his HUD, enabling him to navigate safely through the building.

Moreover, if there is a group of firefighters who, for example, need to fight the blaze or locate trapped occupants, the artificial intelligence can suggest ways in which the firefighters can work together to successfully perform their task.

AUDREY is here
The above example could actually become reality within a few years, as artificial intelligence is already under development. It – or should we say ‘she’ – is called AUDREY, which is an acronym for ‘Assistant for Understanding Data through Reasoning, Extraction, and sYnthesis’. And the above scenarios are just some examples of where AUDREY can be employed.

AUDREY is the result of a joint project between Jet Propulsion Lab (JPL), which is a part of NASA and administered by the California Institute of Technology (CALTECH), and the Department of Homeland Security in the USA. It is part of a larger project called Next Generation First Responders (NGFR), which will enhance safety for emergency services in the field through supporting and improving their focus and communication.

AUDREY is still at an early stage of development, and was tested last summer when it was fed data from various sensors and delivered recommendations to a mobile unit. And within the next year, AUDREY will be tested in real-life situations.

Firefighters’s guardian angel
AUDREY is based on a range of technological breakthroughs which will make it a possible assistant for tomorrow’s firefighters. For example, it is designed to integrate with the ‘internet of things’, where more and more everyday objects are connected to the internet, for example bathroom scales, underfloor heating systems, lighting, fridges and TVs. Even now, AUDREY is able to find the objects, gather data from their sensors and combine this data with data from the sensors which the firefighters carry as part of their equipment.

– When the firefighters are connected to all the sensors, AUDREY will in effect become their guardian angel. Thanks to the data which the sensors are registering, the firefighters will not, for example, run into a room where the floor is collapsing, says Edward Chow, manager at the JPL Civil Program Office and program manager for AUDREY.

Can observe and learn
Before data can be used, it must be filtered and processed.

– The prevalence of minisensors and ‘the internet of things’ can make a huge difference to first responder safety, how they are connected to one another and their understanding of the situation. However, the huge volumes of data are incomprehensible in their raw form and must be synthesised to usable, targeted information, says John Merrill, project manager for NGFR.

AUDREY can do this as well. It knows the different roles in connection with an emergency operation, and can thus provide relevant information to the right people without drowning all the firefighters connected to AUDREY in information. At the same time, AUDREY observes and learns during a call-out. And once it has acquired enough experience, it will predict which resources will be needed later in the call-out based on how previous incidents have progressed. Like all artificial intelligence, AUDREY is only as good as the data it receives. And the more data there is, the greater the likelihood of it being able to supply useful advice and instructions.

– Most artificial intelligence is rule-based: if x happens, then it does y. But what happens if it only receives some of the information? We use complex reasoning to simulate how people think. This makes it possible for us to provide more useful information to the firefighters than with conventional artificial intelligence, says Edward Chow.

 

06.09.17

Protection against both fire and theft

window-brake

Protecting a building against both fire and theft can be a challenge. Security consultants recommend prioritising both types of security, depending on whether or not people are located inside the building.

Fire safety and theft protection are two safety and security objectives that, unfortunately, often work against one another. As safety consultant Maiken Skriver Poulsen explains, when it comes to residential buildings, fire safety is primarily about getting people out of the building, while theft protection involves keeping burglars out.

-If there is a fire, people need to be able to get out without worrying about locks, keys and codes. If a burglar breaks in, on the other hand, we don’t want him to be able to slip out of the front door with all of our property, and that is why it is not easy to protect a building against both fire and theft. If you consider the full picture and make clear choices, though, it is actually possible to do both, says Maiken Skriver Poulsen from the Danish Institute of Fire and Security Technology, DBI.

Are there people in the building or not?
One of the traditional pieces of anti-theft advice is to have a lock on the door that cannot be opened from the inside without a key. It is therefore recommended to avoid thumb-turn locks, as these allow a potential burglar to let himself out with all the stolen goods. If a lock requires a key – and even if the key is left in the lock – it can slow down or create added stress for residents attempting to flee in the event of a fire. That is why Maiken Skriver Poulsen recommends always considering theft protection based on two scenarios: In one scenario, there are people inside the house who may be fast asleep, and in the other scenario the entire family is away from home.

– If the house is empty, there is no reason for having a key in the lock on the inside of the door. Besides, if there is nobody home, it needs to be as difficult as possible for a thief to empty the abode. On the other hand, if there are people inside the house, we recommend leaving the key in the lock on the inside of the door and installing an alarm, Maiken Skriver Poulsen explains, referring to a burglar alarm with motion sensors or a video surveillance system with an alarm.

For businesses, the safety consultant recommends separate security systems depending on whether or not people are found in the building.

Prevention is the best protection
According to Maiken Skriver Poulsen, companies and private citizens should, however, generally implement the most effective means of burglary protection – namely, prevention.

– A survey conducted by the Danish Insurance Association shows that burglars most often break in at the ground level through a window, so this is naturally an area that requires extra attention. The good, old-fashioned tricks are also still effective, such as keeping laundry on the clothes line and rubbish in the bin, says Maiken Skriver Poulsen, and concludes:

– All experiences show that the thief will select houses where it looks like nobody is home. You should therefore always be sure to turn on a light, have cars parked nearby, keep a free line of sight to the house from the street and neighbouring houses, and post clearly visible signs to let people know the alarm is on.

Mobile detectors to prevent construction site fires

mobile-detektorer

Expensive fires at construction sites may become a thing of the past with mobile, wireless detectors.  The technology is already on the British market and is now on its way to the Danish market, too.   

When renovating a building such as an old mansion, one of the first steps is to remove all of the fire safety installations. Next, a group of workers comes in and maybe alters the old electrical installations and often performs hot work. It is almost as if one is actively seeking to start a fire.

In the future, however, it will be possible to protect renovation and construction work with a fire-safety system that uses mobile detectors to pick up heat, smoke or gas to protect a building from fire while the project is underway. In Denmark, several companies have introduced new solutions to the market, and GearTeam is one of them.

– The product comes from England, where, just like Denmark, they have had problems with fires and accidents at construction sites, says Jesper Løvbo, the CEO of GearTeam.

A simple and effective solution
The solution was developed in a collaboration between an English construction company and an electronics producer, and it was therefore designed to address the challenges found at construction sites.

– The system consists of a call point and detectors that are connected wirelessly and can be mounted with two screws. This means that they are easy to use and move around at the construction site, which is always expanding and transforming. The design is simple and is focused on user-friendliness, so that the people at the building site can set them up on their own and connect them to the basic unit located in the foreman’s office. The units run on batteries that have a lifetime of three years, explains Jesper Løvbo.

The call point and detectors can be separated and connected by the hundreds. The basic unit controls the various secondary units, sends messages to the foreman and developer in the event of the alarm, and it can also indicate exactly where in the building an alarm is triggered so that the fire department knows where to go. The individual units detect both smoke and heat.

– In this way, they are better than the fire guards that are required the day after hot work, because the guards cannot see a smouldering fire in the underlying construction. By pressing a button on the detectors, the people at the site can also issue an evacuation alarm, Jesper Løvbo says.

Furthermore, the detectors are able to function with other systems. For example, when building out or on, they can communicate with the ABA system in the existing building so that people inside can also be evacuated in the event of a fire. The system can also communicate with access-control systems at the building site so that barriers automatically go down in the event of an evacuation.

Huge potential in the technology
The hope is that the new solutions are able to improve safety at Denmark’s construction sites, which have traditionally been plagued by fire and accidents.

– We have had big fires at construction and renovation sites here in Denmark. Not only do they delay the project, but they also result in huge damage costs that we naturally would like to avoid. We believe the mobile detectors may be able to prevent some of the damage, says Peter Dræbye, a risk engineer for the Danish insurance company, Codan Forsikring.

London Fire Statement from the CFPA-I

Upper_Grenfell_Tower

The Confederation of Fire Associations-International (CFPA-I) extends its deepest sympathies to the victims of the Grenfell Tower fire and expresses high praise for the work of the emergency services who have been working extremely hard and tirelessly to manage this terrible situation.

This was a devastating fire. As details emerge, we understand there was a refurbishment including exterior cladding and a communal heating system. We are hopeful that the pending investigation will reveal all of the factors that led to this tragic and avoidable loss of life.

The quick fire spread seen in the Grenfell Tower fire is eerily similar to that seen in other similar high-rise fires that have occurred throughout the world, including Australia and the United Arab Emirates. Although the details of the construction of the building are not yet known, reports have indicated that a composite metal cladding with foam insulation was used in the recent refurbishment. At this time, it is not known whether the external cladding had been tested and approved in accordance with the most current fire safety standards.

CFPA-I remains deeply concerned that there are many high-rise buildings around the world that have flammable materials installed with the potential for external fire spread.

It is the view of CFPA-I that building regulations and associated guidance in many locations have not always included safeguards to prevent the use of materials and methods that have poor fire performance capabilities. Even in the absence of strong governmental oversight, architects, engineers, contractors and building owners must embrace fire protection as a fundamental and essential consideration. This includes the proper balance of active and passive fire protection measures, and the on-going inspection, testing and maintenance of all fire and life safety systems.

Many insulating materials are available for use in building construction and their fire performance characteristics can range from being non-combustible to very flammable – it is a matter of choice, and clearly some choices are safer than others.

While we must wait for a full investigation into the cause of the fire and the reasons for such rapid fire spread in this tragic incident, CFPA-I and its member organisations will continue to campaign for improvements in fire safety legislation and in ensuring the safety of the public and our built environment.

This includes:

  • Appropriate alarms, training and evacuation procedures
  • Smoke detection and alarm systems in all residential buildings
  • Controls on the use of flammable façades
  • Proper design, installation and maintenance of fire doors
  • Proper design, installation and maintenance of fire and smoke barriers and the protection of structural components
  • Fire sprinkler protection for all residential and high risk buildings
  • Regular updates of building regulations
  • Initiatives to ensure full compliance with fire and life safety regulations
  • Robust programs for the inspection, testing and maintenance of fire protection systems.

For further information, contact:
Steven Ooi, Chairman:  stevenooi@jayasarana.com
Hatem Kheir, Vice-Chairman: kheir@link.net

A rare self-ignited fire

Røjdrupvej 6 Hobro hus brændt ned foto: Hans RavnIn December 2016, a pyrophoric fire broke out in a house in the Danish town of Hobro – something you only see every few years. According to a researcher in timber, we know very little about pyrophoric fires, because it is an extremely difficult subject to research.    

It was a tragic and extremely rare event that befell the Olesen family in December 2016. Their house was burned to the ground as a result of a self-igniting fire, or pyrophoric fire, to use its scientific name.

– In the burnt-out house in Hobro, we investigated all other possible causes of the fire, but in the end we had to conclude that it was a pyrophoric fire, explains DBI fire investigator Søren B. Mortensen, who investigated the cause of the fire in question.

Normally, pyrophoric fires are something you only see every few years in Denmark.

Long-time effects
Researcher in Timber, Emil Engelund Thybring from the University of Copenhagen explains that pyrophoric fires start when timber is converted into coal after having been exposed to a heat source, for example, a wood-burning stove or hot-water pipes, over an extended period of time.

– Through the effect of heat over many years, the timber dries out and the polymers break down causing chemical changes in the timber which is then converted into a kind of coal. In the presence of oxygen, the chemical reactions generate heat, which can raise the temperature. This can result in a self-perpetuating rise in temperature, causing the timber to smoulder, says Emil Engelund Thybring.

He explains that the lowest documented temperature that is able to cause this chemical change is 77 degrees. By way of comparison, the temperature of hot water in a water pipe is typically around 80 degrees.

Rarely happens
However, according to Emil Engelund Thybring, there has not been much research carried out into pyrophoric fires. The term has been in existence for more than 100 years but, back in the 1990s, many people still believed that pyrophoric fires were a myth.

– It is a difficult subject to research because it can take many years for the timber to be affected so much that there is a risk of it catching fire. It has been documented that the chemical changes in the timber can occur as a result of the timber being affected by heat for anything between three months and 15 years, and there has never been any thorough research over such a long period of time. Furthermore, pyrophoric fires require the ideal combination of oxygen and low humidity, says Emil Engelund Thybring.

A pyrophoric fire, whereby timber self-ignites, occurs very seldom. Over the last 20 years, fire investigator Søren B. Mortensen has investigated between 2,000 and 3,000 fires, and only a few times has he concluded that the cause of the fire was a pyrophoric fire. Prior to the fire in Hobro in December, the last time DBI had come across a case in which timber had self-ignited in this way was five years ago.

Hot work starts fires costing millions

Varmt-arbejde-gnistgivende-værktøj-3

Despite numerous campaigns, the statistics for fires caused by hot work in Denmark are still far too high. In other Nordic countries, there are stringent requirements regarding training and certification and this has reduced the number of costly fires.

One completely normal Monday morning in April last year, a group of workmen laid asphalt roofing on a temporary roof at ’Experimentarium’ in northern Copenhagen. As a result of the hot work being carried out, the roof caught fire. The fire spread so quickly that a roofer had to jump from the roof to save his life. A total of 19 fire engines attended the scene before the fire was brought under control. Once the fire had been extinguished, most of the old buildings had been destroyed by smoke and water damage. The fire had also spread to a neighbouring listed building from 1929, resulting in serious damage.  In all, the fire caused damage running to tens of millions.

The fire was just one of the recent major fires that was caused as a result of hot work. Hot work is work that produces sparks or flames and is common in, for example, roofing or welding work. These are fires that can be avoided because, with the right measures in place, there is no doubt that hot work can be safe work. At the same time, the fires cost vast amounts of money.

Costly fires
The Danish Insurance Association regularly compiles statistics on fires in Denmark. The industry organization’s statistics on fire causing damage running to millions show that hot work accounts for 4% of them. The same fires account for 10% of insurance payouts. In other words, these fires are costly.

– As the fire at ‘Experimentarium’ shows, fires caused by hot work usually spread very quickly and the damage is devastating. Admittedly, the number of fires of this kind is not overwhelming but they cost vast amounts of money, says Christina Christensen, an engineer with the Danish Insurance Association.

However, ironically enough, it is often not the hot work in itself that starts the fire, she explains.

– The workman has the actual flame under control but often it catches on to something else. In roofing, for example, it is the material that lies beneath the asphalt roofing that the workman doesn’t know is flammable. Or, in some cases, the sparks catch on to rubbish lying on the floor when you are cutting metal, explains Christina Christensen.

Huge difference between Denmark and its neighbours
If we look at our Nordic neighbours, the payouts resulting from accidents related to hot work are significantly lower. According to Anders Frost-Jensen, Director of Infrastructure & Quality at DBI, this is because in Norway, Sweden and Finland they have gone much further in terms of training and certification.

– There is a vast difference between Denmark and the other countries in these areas. In the other countries, it is an implicit requirement for hot work that it has to be carried out by workmen who have been trained by certified instructors in the country’s rules for hot work. Moreover, the work site must be made secure by both the developer and the person carrying out the work going through a checklist before hot work is commenced. This is a requirement stipulated by the insurance companies, explains Anders Frost-Jensen.

In Denmark, there is not the same uniform practice within the industry, even though, in Denmark we have described the same rules in DBI Guideline 10. The point is simply that if the insurance companies required everyone who performs hot work to have undergone training in accordance with DBI Guideline 10 and also to complete checklists etc. it would be hinder competition between the insurance companies.

– In the other Nordic countries, they have prioritized safety, whereas in Denmark competitiveness is the priority, explains Anders Frost-Jensen.

Recommend trained workmen
Thus, one insurance company’s policy may be to increase the excess if non-certified employees carry out the work. Another company could perhaps retain the original excess as long as the workmen follow the insurance company’s checklist for what measures have to be in place before, during and after the work. As a policy holder, you could then choose the company you think offers the best solution.

The Danish Insurance Association is urging members to ensure that employees have been trained and that checklists are followed when they are performing hot work. And, in fact, many members are following their recommendation, even though it is not standard practice in the industry.

– The insurance companies are aware of the increased risk with hot work and know that it will be minimized with the use of fire guards and trained personnel. Many of them set out requirements relating to the training of workmen and use their own variation orders which have to be filled out on site, thus ensuring that the proper conditions for the work are in place before it starts, says Christina Christensen.

More concrete practices required
DBI would like to see the recommendation become a more concrete agreement within the industry that that is how it should be. For the sake of safety.

– If these practices are adopted to a greater degree in Denmark, over time we will see a reduction in the number of fires and compensation payouts, as is the cases in the other Nordic countries. The more developers and workmen learn about hot work, the safer it will be for them to carry out the work. Therefore, from a fire safety point of view, DBI recommends that workmen should be trained by certified instructors and they must be able to prove that they have undergone such training by presenting a certificate before commencing hot work, says Anders Frost-Jensen, adding:

– The best example we have seen from our neighbouring countries is in Finland. The insurance industry asked for certifications and that has had a significant effect. The industry in Denmark should do the same. It simply isn’t ambitious enough for society and the insurance industry to continue accepting that hot work accounts for 10% of the total of the millions paid out in compensation for fire, he says.

Explosions in sprinkler system probably caused by hydrogen gas

Sprinklercentral-2

The development of flammable gases in the pipework is the probable cause of the explosions that occurred in two sprinkler systems, injuring several technical employees, back in 2014. A chemical reaction between zinc and water in the pipe system can easily form a flammable hydrogen gas that can lead to an explosion in certain situations. This is one of the conclusions in a new report published via Finance Norway.

In 2014, there were explosions in two different sprinkler systems in Denmark. The first occurred at the premises of the Danish company Movianto in Greve, where a service engineer was injured, even though the explosion actually moved out into the open air. And, shortly afterwards, in the department store Magasin in Lyngby north of Copenhagen, where an installation contractor was burned because an explosion occurred in a large pressure storage tank in a small room with the result that the explosion was particularly powerful. On both occasions, the sprinkler system ignited and exploded due to a flammable gas in the system following the draining of water.

A new technical report published via Finance Norway concludes that hydrogen can be formed due to a chemical reaction in the ‘wet’ zinc-coated pipe system. As zinc-coated pipe installations are often used in sprinkler systems in Denmark, the report’s conclusions constitute extremely important information – not least for those people who work with sprinkler systems.

– There was obviously a chemical reaction between the zinc and the water in the pipe, after which the hydrogen in the water was secreted and ignited by sparks created during the emptying of water in the sprinkler installation, explains Anders Frost-Jensen, Director in DBI.

Only in Scandinavia
Flemming Lindegaard, an inspector with the Danish Working Environment Authority, also points to a clear link between hydrogen in the pipe system and the explosion which occurred in Magasin. The secreted hydrogen has thus formed gas pockets and increased the pressure in the closed piping in the system. The gas escaped during operational and maintenance work, whereby the pipes were opened in order to discharge the water. In the open air, the gas mixed with the oxygen, reaching a critical concentration, which was then ignited by sparks from tools. This trio, consisting of a source of ignition, a flammable gas and oxygen, led to combustion which resulted in an explosion that was so powerful that, in the worst case scenario, can move concrete walls.

– We have, via our international work, made inquiries regarding experiences in the area throughout Europe. However, it is a phenomenon that we have only experienced in Scandinavia so far, says Anders Frost-Jensen, before elaborating:

– There can be several explanations as to how we are witnessing these explosions now and hearing about flames resulting from maintenance work. The fact is that within the last ten years we have been working with zinc-coated piping in sprinkler systems instead of black steel pipes, and the results from Norway show that the risk of an explosion is greater when zinc pipes are used. Moreover, it seems that it is possible to prove a link to the quality of the water in the area in which the installation is located, including the pH value of the water quality, because it could have helped increase the production of hydrogen in the pipe system, he explains.

Revision of sprinkler guidelines
In collaboration with a Standing Technical Committee, DBI now intends to incorporate the relevant conditions and experiences from Norway into the Danish sprinkler guidelines so that the risk of further accidents related to operational and maintenance work on sprinkler systems is minimised as far as possible.

– However, we are already able to make some recommendations and emphasise the importance of checking for abnormal increases in pressure in pipe systems and use non-sparking tools when emptying water from the system, says Anders Frost-Jensen.

In addition, the Danish Working Environment authority has issued a number of recommendations as to how work on sprinkler systems can be carried out safely. These include the use of gas detectors or explosimeters for measuring the concentration of hydrogen, recommending that no work is being carried out while the sprinkler system is being emptied, ensuring that there is good ventilation while the system is being emptied so that any hydrogen is removed from the site it is generated, and that electrical installations in the sprinkler room are installed correctly so that the generation of sparks is avoided.

DBI investigates the fire safety of batteries in ferry project

e-ferry-web

Batteries are not only making their way into our buildings. They are also making inroads into the transport sector.

They can be found in, for example, hybrid cars and also in ferries, which use battery packs as a supplement to their diesel engines. And now, the first all-electric ferry is on its way to Denmark. It is being planned for the so-called E-Ferry Project, which is an EU project. The project is still in embryo and, more specifically, work is being carried out on the routes between the Danish islands of Ærø and Funen and between Ærø and Als.

It is hoped that the electric ferries will be put into operation in 2017. DBI is involved in the project and is focusing on fire safety with regard to batteries as well as the lightweight plastic components the owners would like to use in the construction of the ferry to reduce its weight.

– There are EU standards for batteries in which fire safety in relation to operational situations has been incorporated, but they do not deal with fire safety in the event of an accident occurring. For example, there is a big difference between handling a single battery in a safe way and handling a large bank of batteries that are involved in a fire. Battery systems have slipped under the radar slightly in relation to fire safety since batteries come under the standardisation organisation CENELEC, which normally doesn’t work with determining the impact on fire parameters such as heat and smoke generation. However, these parameters should be determined in order to assess the fire risk in the case of an accident, says Martin Pauner, who is a civil engineer with DBI, and involved in the E-Ferry Project.

Just as on land, batteries entail a lot of unknown factors in relation to fire safety at sea: How do different types of battery react to saltwater, when they get damaged during a sailing or if a fire breaks out elsewhere on the ferry. And, how good are the different batteries’ cells at preventing the spread of the fire in the event of ‘thermal runaway’ in an individual cell?

These are just some of the questions that DBI will attempt to find an answer to in relation to the project.

Batteries and fire hazards making their way into our buildings

solceller

Batteries are making their way into our buildings. Here, they collect energy from solar cells and provide us with smart energy consumption. However, they also constitute a fire hazard that is difficult to manage and, in actual fact, there are no regulations governing this area.

It makes good sense to store power. If you have solar cells on your roof, you can store energy during the day and use it in the evening and during the night. In particular, house-owners with solar cells installed under the new scheme which dictates that power from solar cells is used in the same hour as it is produced, can only sigh at such an opportunity. Not to mention the even greater potential in being able to store power from wind turbines which we currently export abroad for a pittance whenever the wind blows. This greater potential lies some way off in the future but solutions with large batteries for buildings, so-called power packs, are advancing at great speed – particularly in the USA.

The batteries will be installed in buildings where they will be used to store power from the solar panels on the building or to purchase power when prices are low – typically during the night when demand is low – to be used later when prices increase again. This phenomenon is called ‘peak shaving’, because you are shaving the top off the price of electricity, and there is the potential for saving large amounts of money.

However, installing such a large energy-storing component in a building is not necessarily without its problems. Especially not when the fire properties of the different types of batteries are largely unknown.

Explosions and flammable gas
There are many types of batteries that use different chemical components, all of which react differently to fire. One of the most commonly found types of battery is the lithium-ion battery that you see in various American power packs and also in the Tesla Powerwall. It has become popular because it is lightweight and is able to store a lot of energy in relation to its size. It also functions well when it is recharged and the power can be stored for longer periods without losing any voltage. And then, it reacts to heat.

– If a lithium-ion battery gets too hot, it will, at some point, experience ‘thermal runaway’, meaning, for example, that the electrolyte in the battery vaporises with the result that eventually the cell will no longer be able to contain the pressure. Many batteries have a safety mechanism in the form of ventilation if the pressure gets too high which prevents the battery exploding, explains Petra Andersson, who is a senior researcher in the Fire Research department at the SP Technical Research Institute of Sweden and who has carried out research into lithium-ion batteries and fire.

Regardless of whether the cell releases the vaporised electrolyte or explodes, the result is the immediate emission of highly flammable gas. This is because the vaporised electrolyte in lithium-ion batteries is combustible. It has more or less the same fire properties as propane, which you will be familiar with from the liquid gas in lighters.

Toxic gas and difficulty extinguishing
A battery can heat up if it is overcharged or used incorrectly. A Battery Management System (BMS) is intended to prevent this. However, it can also happen if a fire breaks out in a building in which a power pack has been installed. Different lithium-ion batteries have different electrolytes which react at different temperatures, but a battery temperature of around 100 degrees results in a risk of gas being emitted.

– If the gases from the battery escape when there is already a fire in the room, the gas is ignited immediately. If there is no source of ignition and the gas escapes from the batteries, it will accumulate as the individual cells, which make up large lithium-ion batteries release it, thus causing a bigger and more serious explosion, explains Petra Andersson.

A lithium-ion battery doesn’t just emit flammable gas when it gets hot or burns. Depending on the materials in the battery, it also releases large number of toxic gases, for example, hydrogen fluoride which, even in small doses, can be life-threatening.

And, as if flammable gas, the risk of explosion and toxic gas wasn’t enough, there is also the small detail in lithium-ion batteries that they are difficult to extinguish if they happen to catch fire. Tests from the USA show that even though a fire in a battery has apparently been put out, some cells in it can experience ‘thermal runaway’ and flare up again hours, days or even weeks after it has been extinguished. At the same time, thermal imaging of the battery will not show whether it will flare up again or not.

More research needed
As mentioned previously, different batteries have different fire properties. But, irrespective of which type of battery it is, there are no rules governing the set-up of batteries in the Danish Building Code or standards for how they are to be installed with fire safety in mind. This is because batteries in buildings are a new technology.

– As far as I am aware, no research has been conducted into how you fireproof buildings with batteries or how you approach batteries in a building with a view to extinguishing them if they catch fire. If the power pack technology starts to become more prevalent, there will be a real need for more research, explains Petra Andersson.

Research is necessary because, for example, different batteries react differently to, say, water. A lithium-ion battery can be extinguished using water in reasonable amounts. However, if you spray water on a lithium battery, there is a risk that the lithium mixed with the water can develop into the flammable gas, hydrogen. In the context of fire technology, it means that different batteries require different fire technology initiatives.

– There are a vast number of considerations in this area which require investigation and research. This is because it is simply unacceptable for us, as a society, are unable to do anything if, for example, a fire breaks out in a power pack installed in a block of flats, says Director for Customers & Relations in DBI, Ib Bertelsen, before continuing:

– At the moment, we know very little about how we should tackle this. It depends a lot on which type of battery you are talking about, whether it is a large system in an industrial set-up or a smaller system in a domestic set-up, and often customised solutions will be required. Some of the options you could consider for large power packs are, for example, aspiration smoke detection systems, which are extremely sensitive and take samples of the air at regular intervals in order to detect a fire, inert gas and, potentially, sprinkling. With regard to smaller power packs, the same could apply to BS-60 cabinets. However, there is a need for more knowledge and research in the area, he emphasises.

Permanent oxygen reduction provides effective fire protection

Tour-de-France-ryttere

A standard is on the way which will make permanent oxygen reduction an effective alternative to sprinkling in Denmark. The Danish Working Environment Authority has no objections in principle.

In future, it may be easier to fireproof, for example, high bay warehouses and storerooms in museums – and, at the same time, reduce the risk of damage caused by sprinkling. This is because plans for a forthcoming European standard for the design of systems for permanent oxygen reduction are due to be passed in 2016 and issued in 2017.

The forthcoming standard is called EN 16750 Fixed firefighting systems — Oxygen reduction systems — Design, installation, planning and maintenance. It has been drawn up by the European standard organisation, CEN, in a working group set up under CEN/TC 191/WG6 with the participation of fire technology consultant Rolf Knudsen from DBI.

– Permanent oxygen reduction is an alternative to extinguishing fires by means of, for example, sprinkling, where there is otherwise a need for a sprinkler more or less above every pallet at all levels. With a permanent oxygen reduction system you can fireproof the whole warehouse more easily and, at the same time, avoid the often costly water damage that is caused when a sprinkler system has been activated, explains Rolf Knudsen.

The working environment
The reduced oxygen concentrations do not exclude people from working in the buildings – provided, of course, that a number of safety requirements are complied with.

– There are no immediate physiological problems with being in a room with an oxygen concentration of, say, 15%, if you are otherwise fit and healthy and do not need to perform any physically hard work for long periods, insists Rolf Knudsen.

In fact, many people have experienced an equally low oxygen concentration when they have been on an aeroplane. The air in the pressurised cabin is equivalent to air with an oxygen concentration of around 15.5% volume on the ground. This is the same as being approximately 2,400 metres above sea level.

– In both the UK and Germany there are rules governing how long you may work in reduced oxygen conditions, says Rolf Knudsen.

More extreme proof is provided by cyclists, who prove that it is even possible to perform extremely hard physical work in conditions with low concentrations of oxygen. What Tour de France cyclists have to endure in, for example, L’Alpe d’Huez, is not just down to the steep mountain roads, but is also due to the fact the oxygen levels in the ‘thin air’ at 3,300 metres is equivalent to an oxygen concentration of just 13.8% volume on the ground.

Green light from the Danish Working Environment Authority
The Danish Working Environment Authority has no objections in principle to permanent oxygen reduction as a means of fireproofing.

– We are positively disposed towards the principle if various criteria and limits are complied with in relation to work safety. Here, we will work on the basis of the Germany safety requirements outlined in BGI/GUV-I 5162, drawn up by the German Institute for Work and Health (DGUV) with information on working in oxygen-reduced atmospheres, explains Erik Lund Lauridsen from the Danish Working Environment Authority.

The German regulation has, for example, four fire classifications for different oxygen concentrations. In Class 0, the oxygen concentration is above 17. Here, the only safety requirement is that employees have to undergo special instruction.

In Class 1 (17.0 % vol. – 15% vol.) employees also have to undergo an occupational health examination to exclude the presence of, for example, heart disease or other risks. In addition, there is a requirement for a half-hour break to be taken in a ‘normal’ atmosphere after four hours of work.

I Class 2 (15.0 %. vol. – 13.0 % vol.) the requirements are the same, the only difference being that the break has to be taken after two hours’ work. In Class 3, with an oxygen concentration of below 13% vol., it is forbidden to be in the room without special measures being in place.

– In addition, there are a number of requirements relating to the actual systems. For example, both the measurement and control of oxygen concentration must be reliable and there must be assurances that the oxygen concentration is not able to fall too low by mistake. This requires the use of approved equipment and regular inspections, stresses Erik Lund Lauridsen.

Likewise, it must be ensured that the oxygen-reduced atmosphere cannot spread to other rooms in the building.

Classic fire theory
The principle of oxygen reduction is based on the classic ‘fire triangle’ whereby the prerequisites for a fire are heat, oxygen and flammable material. In other words, this means that you must permanently maintain an atmosphere in which the stored material cannot burn.

Ordinary air contains approximately 21 % vol. oxygen, which can fuel a fire, but if the oxygen content is reduced to, for example, 15% vol., a flaming fire is not possible for materials such as wood, cardboard and several types of plaster. From the 15% vol. a number safety and sensor tolerances have to be subtracted, and for that reason the required oxygen concentration will be approximately 2% vol. less than the required ignition limits for the material that is to be protected.

The oxygen is reduced by adding extra nitrogen to the air in the protected building, which previously amounted to approximately 80% vol. of atmospheric air. This can be done by either blowing pure nitrogen or a mixture of nitrogen/air into the building, which by its very nature must be relatively air-tight.

– The standard will include rules relating to the design of oxygen reduction systems. For example, you can find tables specifying the maximum permitted oxygen concentration based on the materials that are to be protected, explains Rolf Knudsen.

In the case of more specialized materials, the standard refers to how it is possible to find the maximum oxygen concentration by means of a test.

Fireproofing by means of permanent oxygen reduction is already used to some extent in, for example, Germany, the UK, Spain, Switzerland and Norway for fireproofing warehouses, freezer rooms and server rooms.