Author Archives: denmark

Many fire protection systems are faulty

sprinkler

Approximately 70% of automatic fire alarm systems and more than 50% of sprinkler systems in Danish companies and public institutions are faulty when they are inspected. That is the result of an analysis conducted by the Danish Institute of Fire and Security Technology, DBI, on the basis of figures from 2015 and 2016.

DBI inspects fire protection systems once a year and finds many different types of faults in the process. A new analysis conducted by DBI shows that only a very small percentage of the faults are so critical that the systems have to be discarded. However, less critical faults can also be serious enough in themselves. For example, faults in automatic fire alarm systems can lead to false alarms and delays in raising the alert, while faults in sprinkler systems can result in a fire spreading to areas not protected by a sprinkler system much more ferociously.

– The faults seldom mean that a system fails completely in the event of a fire, but delays can have serious consequences and false alarms contribute to undermining users’ confidence in alarm systems, says Anders Frost-Jensen, Director of Infrastructure & Quality in DBI.

Errors in orientation plans
Around half of the faults are actually administrative errors, DBI’s analysis shows, and it is orientation plans of the building and the system in particular that are lagging behind.

– If the orientation plans are wrong, it could take the fire brigade quite a long time to find the right room or area when the alarm goes off. Time is the crucial factor when it comes to the development of a fire and the safety risk. And if you have forgotten to fit detectors in a room following a refurbishment, the fire will be detected much later than it should be, explains Anders Frost-Jensen.

Work pressure and increased complexity
The 70% is the highest number of faults and errors that DBI has recorded in its statistics up to now, and the figure has been rising sharply in recent years. However, a third of the faults can be classed as installation faults which, according to the DBI Director, are partly due to work pressure on the part of the installers and partly due to increased complexity in the buildings.

– Buildings are constructed differently nowadays and different systems often have to be integrated with one another. That makes it difficult to assess whether the systems have been installed correctly, says Anders Frost-Jensen.

Bullet-resistant glass rarely the best security solution

Bulletproof glas

Demand for bullet-resistant glass is rising, but in most cases it is an unnecessary investment. Instead the focus should be on general security and more appropriate measures. 

Bullet-resistant glass has become popular in recent years. There are no overall figures for demand, but the sector is in no doubt. Glassmakers report higher demand, and even smaller companies are experiencing a rising interest in security glass, i.e. bullet and blast-resistant glass.

– We are seeing it more and more. A few years ago, we had an average of three to four inquiries per year for bullet-resistant glass. Today, we get 15-20 inquiries, with a preference for the heavier and larger solutions, explains Henrik Torp, a glazier at Glarmestre Snoer & Sønner A/S in Copenhagen.

– Part of the rise is probably due to the significant price falls for this type of glass over the last few years, he says.

The customers seeking more secure solutions are extremely diverse. For example, they include religious congregations, large public offices, hotels and even the odd private individual.

Other and better solutions
There may be good reasons for selecting glass which has been protected in some way. If a bomb goes off near glass, the glass splinters apart and the pieces are ejected like missiles.

– In this case, the glass will become a weapon. The shock wave combined with glass can cause massive injury, explains Per Frost, emergency management and risks advisor at the Danish Institute of Fire and Security Technology (DBI).

– But for by far the majority of customers, protection against explosion and terrorism is setting the bar too high. If a business is subjected to terror, it will typically be the employees who can provide access to particular systems or areas who will be threatened. In these cases, bullet-resistant glass will not be the right solution. Access control management and area zoning will be far more effective in protecting personnel at the workplace, Frost states.

If a company, against all odds, really is a potential terror target, pre-detection is also a better way of ensuring protection.

– All attacks require preparation. Pre-detection uses surveillance systems to check whether there is anyone inside the building perimeter, or to see whether anyone is repeatedly observing the building. These people are detected before an incident takes place. A security guard can then be dispatched, or the authorities can be contacted regarding a justified suspicion about a coming attack, and in this way the incident can hopefully be avoided, Frost says.

Only necessary if the police say so
There are relatively few locations where bullet and blast-resistant glass is necessary.

– But there may be a good business case for it in buildings which have frequently and repeatedly been subjected to vandalism – for instance, schools. Often the same panes of glass are destroyed each time, and in this case, the higher cost of the security glass could be quickly recouped, Frost explains.

Generally, however, bullet-resistant glass is mainly necessary when required as part of a security evaluation by the police.

– Or if you are handling high-value items – e.g. at currency exchange locations or in connection with security transport. In these cases, bullet-resistant glass may make sense, though, even here, it is not always the right solution. For watchmakers and goldsmiths, it will often be enough to have showcases of strengthened glass, able to withstand blows and tools, while securing the valuables in a safe at night, Frost says, and continues:

– The best thing is to look at the total security picture and make an overall assessment. This will show you other security options.

Tendering is expanding the use of bullet-resistant glass
So, if it’s not specific needs, what’s the reason for this trend?

– There is a tendency for bullet-resistant glass to become a competitive parameter in today’s new build projects. If two identical buildings cost the same and one has bullet-resistant glass, that’s the one you go for. It sends a signal that you are keeping up with trends, even if in reality the glass will rarely solve a security problem, because there is no day-to-day threat where bullet-resistant glass would be a help. But even so, the glass can be a sales argument, Frost says, and explains it in this way:

– It’s like needing a new car where one has a top speed of 100 km/h and another 200 km/h. If you never drive above 100 km/h, which one do you actually need? The same goes for bullet-resistant glass. It’s often unnecessary, and there are many other solutions.

 

 

Denmark’s most fireproof battery

Lüders - Credit By & Havn / Peter Sørensen

Batteries in buildings ­– the so-called powerpacks – have arrived in Denmark. In 2017, a 460 kWh battery will be installed in the ground floor of Lüders multi-storey car park at Nordhavn in Copenhagen. Here, it will be encased in its own fire cell and secured by means of inert gas and sprinkler system and an automatic fire alarm system.

Battery technology is part of the solution to the energy issues of the future. These issues, which include how we are going to get more sustainable energy from the sun and wind into our electrical grids, and, at the same time, have energy when the sun isn’t shining or the wind isn’t blowing. Better and more cost-effective battery technology means that, in the USA and some places in Europe are already well underway with installing batteries in buildings that charge when the price of electricity is low and contribute to the building’s electricity consumption when the price is high.

And, the same technology is now coming to Denmark. Initially, it won’t provide electricity to buildings but provide it to the local electrical grid instead. Specifically, Lüders multi-storey car park in Copenhagen’s Nordhavn area, electricity network operator Radius is installing a 460 kWh battery – the equivalent of the daily electricity consumption of 32 average families.

– When the energy requirement is greatest, the battery will slice the top off the strain on the electrical grid. The grid is dimensioned to handle the peak loads that only arise a few times a year. If the battery can help ensure a power supply when the load is at its highest, we can reduce our plant and operating costs in the electrical grid, explains Ole Pedersen, Technical Asset Analyst with Radius.

The battery is one of several trials in an overall project entitled EnergyLab Nordhavn, which is testing the interplay between a number of energy solutions in the new neighbourhood in the capital.

– We anticipate that the battery, which is a lithium-ion battery supplied by ABB, will be operational in February 2017. The EnergyLab Nordhavn project will finish in 2019, but the battery’s service life is 10-12 years, Ole Pedersen explains.

Prepared for the worst
Battery technology of this type and size in a building is new and is associated with various other fire technical challenges. For example, lithium-ion batteries can overheat and burst into flames or emit explosive gases and oxygen, even though the battery’s BMS (Battery Management System) minimizes the risk.

Also, knowledge of how the batteries react to fire, extinguishing and whether or not they constitute a risk in the event of a fire, is limited. The fire safety properties of the battery have to be taken into account.

– The building’s electrical installations and the battery are kept separate from each other. The five racks of battery cells, which together make up the actual battery, are located in their own battery cell constructed with a minimum of 150 mm of reinforced concrete. In each rack there are sensors which constantly monitor each cell and register heat and fire, Ole Pedersen tells us.

If there are problems with the generation of heat, the system automatically sends an alarm to the fire brigade. In addition, an inert gas device, connected to each individual rack, has been installed. That way, the system can reduce the oxygen content in the specific rack in which the heat is being generated, thus preventing it from bursting into flames.

– There is also a sprinkler system with no water installed in the room with a sprinkler head located above each rack. When the fire brigade arrive, they will make an assessment as to whether they will go into the room containing the battery to take a closer look at it. If they don’t want to do that, they can attach a fire hose to the sprinkler system from the outside and inundate the room, explains Ole Pedersen, adding:

– We hope that it never comes to that, because the water would destroy everything in the room. But we need to have a plan for the worst case scenario.

A good place to start
The fire technical solution has come to fruition through a collaboration with ABB (who have previously installed similar batteries abroad) and DBI. The Copenhagen Fire Brigade was also involved. But, how do you actually assess fire safety when the technology is brand new and there are no rules governing it.

– There is nothing in Denmark we could compare it with. Instead, we looked to the USA, where the National Fire Protection Association (NFPA) has also been considering the same issue. Previously, we were used to dealing with acid and lead batteries whereby, according to NFPA’s rules, you could have up to 600 kWh in the same room. We have only just started looking at lithium batteries and whether they behave differently to the other batteries, says René Ruusunen, who is Senior Fire Engineer with Copenhagen Fire Brigade. He continues:

– On the basis of the NFPA’s 600 kWh rule, we came to the conclusion that the battery was adequately protected and that we would not have to lay down any specific requirements with regard to their installation in order to ensure safe extinguishing and rescue conditions. However, it doesn’t mean that you will be able to freely install all batteries under 600 kWh in future. The things that require approval will change as we learn more about the fire properties of the batteries. If you want to install a battery, you must contact the local fire authorities in all cases.

– At the same time, the battery has been installed in a multi-storey car park where the footfall is low and there is direct access from the open air so that we can get to it easily in the event of a fire. In that sense, it is a good place to install the first battery of its type, says Morten Valkvist, fire engineer with Copenhagen Fire Brigade.

More electricity for your money
If the technology lives up to expectations, the battery in Nordhavn could quickly become the first of many.

– We expect that it will make good economic sense. They can help us reduce construction costs and get the optimal return from the money we invest. In future, with less expensive batteries they could become an alternative to the traditional ways of supplying the electrical grid in peripheral areas. At the same time, the batteries can be used for spectrum regulation of the electrical grid, which will become more pertinent as energy production becomes less centralized due to solar cells and wind turbines, says Ole Pedersen.

Even though the level of fire safety is high, it won’t be the related costs that stand in the way of the technology. The fact is that fire safety only accounts for 3-5% of the total cost of the battery.

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.

DNA spray keeps the burglars away

DNA Spray 7-eleven Hvidovre 1

The DNA sprays being used by retailers are a success – they are proving extremely effective at preventing theft. Therefore, several Danish food chains are now installing DNA spray solutions in their shops, even though DNA spray has never been used in investigating crimes or as evidence in a court of law.

In September 2014, the Dansk Supermarked Group (a Danish supermarket chain) installed Selecta DNA spray on a trial basis in nine selected shops in a district of Copenhagen. The system functions by spraying the burglar with DNA fluid as he escapes the shop premises. The liquid contains a unique DNA signature that can be traced back to the individual shop and which adheres to skin and clothing and stands out when exposed to UV light. The hope was that the police could use it when investigating burglaries, and that the new technology would also have a preventive effect – which it undoubtedly has.

– In our experience, the DNA spray has been very effective at deterring burglars. In the nine shops where the system was installed, there has only been one burglary since the solution was implemented. Here, however, due to human error, the spray was not released, says Jess Pedersen, Head of Group Security at the Dansk Supermarked Group.

Based on the positive experience from Copenhagen, the Dansk Supermarked Group has decided to install the system in more of its shops. Ten stores in northern Zealand have already had the system installed, and next stage involves installing it at 30 other shops throughout Denmark.

However, the Dansk Supermarked Group is not the only retailer to have discovered the new technology. Chains such as McDonald’s, 7-Eleven and Coop Danmark have also installed the DNA spray system or plan to do so. Rema 1000 has also embraced the solution, and in 2016 is installing it in all the company’s shops in Denmark.

Primarily preventive
Both the Rema 1000 shops and the Dansk Supermarked Group’s Netto shops have signs outside at the front and on the windows at the entrance clearly stating that the shop uses DNA spray. It is the preventive effect of the the solution that is so positive.

– Our aim is that burglars give up and walk away on seeing that we use DNA spray. This way, we are also protecting our employees from very disturbing and unpleasant experiences, says Jess Pedersen.

In fact, the preventive effect has been such that it has still not been necessary to investigate a single burglary where the DNA spray has been released. But the methods for using the DNA traces are nevertheless in place.

– We are ready to act and use the traces from the invisible marking. And all the police districts already have UV equipment which is used for many other purposes. If we have a suspect in custody, we can shine UV light on him and remove a sample of the artificial DNA, which we can then take to the company that supplied the solution to identify the shop where the DNA comes from, says Jørn Kjer, who heads the Danish National Police’s national prevention centre.

Ends with confessions
As there have still not been any burglaries in Denmark where the DNA spray has been used, there is some uncertainty regarding how much validity a Danish court will give to using DNA traces as evidence in a court case. And it might be some time before we find out.

– In the cases we have seen in other countries, where people have been confronted with the fact that they have been sprayed with DNA spray, they have quickly confessed to the crime. We also have examples of burglaries from residential properties, where money has been marked with DNA, and when a suspect has been arrested with DNA traces on his fingers, he has confessed his guilt. Thus, the cases there have been have been conducted as cases where the accused pleads guilty without the court considering concrete evidence, says Henrik Olsen, CEO of Unisecure, which manufactures one of the various DNA spray solutions.

 

The CE mark gives a false sense of security

usb-chargerCan a charger you have purchased for your smart phone or tablet give you an electric shock or burst into flames? Maybe. Even though it carries the CE mark, it is far from certain that it meets the requirements set out by the mark.

Have you checked that the USB charger you recently bought carried the CE mark? It should, in fact, not be necessary, because all electronics that are imported into or produced in the European Economic Area, the EEA (i.e. the 28 EU nations in addition to Norway, Iceland and Liechtenstein) must be CE-marked. And it is certain that the charger will bear the CE mark somewhere. The problem is just that it doesn’t necessarily mean that the product meets the requirements the CE mark entails. In this case, it is quite simply dangerous to use.

– We are seeing more and more products that do not meet the requirements, and this is an indication that there is an increase in the number of products that either have not been properly tested or that simply have had a CE mark added without being tested – in other words, cheating, says Søren Petersen, a senior consultant in the department for Approval Management in the Danish GTS Institute, DELTA, who, for example, are responsible for testing electronics for the purpose of CE marking.

Potentially deadly
Electronic equipment, such as chargers for smart phones and tablets must, for example, comply with the EU’s Low Voltage Directive in order to be CE marked and to allow them to be sold on the market in the EEA. The Directive stipulates that the product meets the requirements of all directives that are concerned with safety, which means that it must protect humans, animals and property against fire, shocks, toxic smoke and many other things. It also means that products that do not comply with the CE mark can potentially burst into flames – as happened, for example, to a family in the Danish town of Hobro, whose basement was gutted by fire in February of this year. Chargers that do not comply with the CE mark can also pose a risk of electric shocks and emitting toxic smoke.

– If a product meets the requirements for the CE marking, the plastic components on a charger shouldn’t be flammable or, at the very least, be self-extinguishing within a short space of time. In addition, it should be able to cope with large voltage surges as a result of, for example, lightning strikes, without causing electric shocks or bursting into flames. It is just that it has turned out that, in some cases, the plastic is flammable and that other small defects in the equipment can result in a fire, even though this should not be possible with products carrying the CE mark. It will quite often be a case of a very limited fire, but if it happens in a house during the night, it can potentially develop into a fatal fire. Therefore, some of these products are potentially lethal, explains Søren Petersen.

Counterfeit goods from Asia
All products break down at some point, and there is also a risk that they can get water-damaged or lost during transportation with the result that they no longer meet the requirements.

– However, in my estimation, this is highly unlikely to happen, so that isn’t where the problem lies, says Søren Petersen.

The problem is more that some manufacturers – typically in Asia, where chargers can be produced cheaply – CE mark their products without testing whether the product actually meets all the requirements. Anas Salam, an investigator with DBI, explains it.

– Marks are some of the simplest things to falsify. Typically, a manufacturer produces a product that meets the requirements and it is then tested and approved. Subsequently, they become more relaxed about the requirements in order to minimise costs and maximise profits. Thus, in reality, the product is no longer tested, even though it still carries the mark, he explains.

When the products enter the EEA, it is up to the importers to check that the products have been marked and that they actually meet the requirements of the mark. This is done by looking at the certificates from impartial laboratories or by having the item tested by an impartial laboratory, such as DELTA. However, with the internet there are also many private individuals who have started to import and sell products.

– They are not bound by standards and rules in the same way as organised importers are and, at the same time, it is an easy way of earning money. Previously, you had more control over the importation of goods because it was more difficult to find a manufacturer and more difficult to sell the product. However, that is no longer the case, explains Anas Salam.

Better controls on the part of the importers
However, there are strong indications that the importers are not sufficiently aware of whether the products they are buying comply with the mark they carry. In March 2016, four out of nine non-original chargers purchased by the DR1 programme Kontant were unsafe to use. And, in 2013, the Swedish Elsäkerhedsverket (corresponds to the Danish Safety Technology Authority) conducted tests on ten chargers. All of them were subsequently taken off the market. At the Danish Safety Technology Authority, which conducts risk-based random tests on, for instance, electrical equipment, they are also aware of the problem.

– Small chargers are an area we are focussing on, and at the beginning of the year we started a control campaign on these chargers. One of the reasons for this was that many of them were failing the random checks, says Lone Hansen, who is a communications consultant with the Danish Safety Technology Authority.

The campaign includes around 120 chargers that have been registered in a screening of the market. A number of these are about to examined further through document controls or testing. However, it isn’t possible for the Danish Safety Technology Authority to test every single product that comes into the country. Therefore, it is recommended that the importers get better at doing it instead.

– It is the importers’ responsibility, and it them who are best able to ensure that the products they sell in their businesses comply with the safety requirements. They can, for example, carry out random tests on the goods or have them tested before they start to sell them. And they have every reason to do so. You see, no trader should be interested in selling products that aren’t safe. Indeed, if products are taken off the shelves or recalled from consumers, it damages the business’s reputation and sales, says Lone Hansen. Søren Petersen agrees.

– As an importer, you should screen your products and test them if you are in any doubt. It is the responsibility of the importer and the seller to ensure that the products meet the requirements of the CE mark, and they are liable to pay compensation if the product causes injury or damage, explains Søren Petersen.
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The CE Mark
CE stands for Conformité Européenne (European Conformity) and is a mark which electrical equipment must carry in order for it to be produced and/or sold in the European Economic Area (EEA). The mark is – if the product is compliant – the manufacturer’s guarantee that it meets the requirements of all the relevant EU directives concerned with safety. Products carrying the CE mark can be moved freely across national boundaries and sold within the EEA.

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.