Special Issue “Innovative Flame Retardants”

A special issue of Molecules:  Click here

Dear Colleagues,

Research has increasingly focused on the development of biobased materials to attain the requirements of sustainability. Developing biosourced materials in the future includes polymers as well as additives. Among these additives, flame retardants are the most important market. Bioresources are numerous and provide many opportunities to develop innovative flame retardants. Solutions based on carbohydrates, polyphenols, lipids, or proteins are currently being investigated.


To be commercially successful, biobased flame retardants must obviously be as efficient as oil-based ones. However, cost may also be a major drawback. Indeed, the development of biobased flame retardants often needs various extraction, purification, and functionalization steps. A solution to be competitive may be to provide multifunctionalities. For instance, combining flame retardancy with anti-aging, plasticizing, crosslinking, conductive properties, and so on would be highly desirable.

This Special Issue aims to gather high-quality papers about the extraction, synthesis, and functionalization of biobased flame retardants, as well as the assessment of their fire proofing properties. Investigations can consider, fully or partially, biobased flame retardants. Multifunctional biobased additives combining several properties (including flame retardancy) will be privileged. Papers on the life-cycle analysis (LCA) of such additives are welcomed.

Dr. Rodolphe Sonnier
Dr. Laurent Ferry
Dr. Henri Vahabi
Guest Editors



New Insights into the Investigation of Smoke Production Using a Cone Calorimeter

Published paper in Fire Technology , 01.01.2019


Smoke release data from the cone calorimeter are often underused. They may provide additional information to better understand the fire reaction of polymers and the efficiency of flame retardants. A new method is proposed to investigate the smoke release in cone calorimeter tests and to correlate it to heat release, based on studies with pure and flame retarded polymers. Smoke release rate is plotted versus heat release rate and new parameters are pointed out. In particular, parameter A represents the smoke release per unit energy (in Joules) released. Its value increases when the carbon fraction and the aromaticity of a polymer increase. It can reach around 0.05 m2/kJ for epoxy resins but is null for well-known smoke-free polyoxymethylene (POM). HRR threshold (HRRth) represents the critical heat release rate above which smoke release is measured. Its value is close to 100 kW/m2 for polyolefins but decreases drastically for aromatic polymers. The approach developed in this study is potentially useful for assessing the smoke release of different materials for a heat release rate scenario chosen arbitrarily. The influence of two specific smoke suppressants and of two specific flame retardants on smoke release is also discussed and the proposed method allows for a better understanding of their role in smoke release.


Call for evidence- UK fire safety regulatory guidance

On 18 December the British Government published a call for evidence as the first stage of a review of its fire safety regulatory guidance. Nothing is excluded. The current scope of the regulations only concerns life safety but the review invites thoughts on whether this should be extended to include property protection for certain buildings. The deadline for responses is 1 March 2019 (Source: European Fire Sprinkler Network). For more information: click here


Fire safe 2019!

“Flame retardancy of polymers” wishes you a fire safe 2019!



European Meeting on Fire Retardant Polymeric Materials (FRPM19)

The biannual European Meeting on Fire Retardant Polymeric Materials (FRPM19) will be held from 26th to 28th June 2019, with a conference reception taking place on Tuesday, 25 th June, in Turku, Finland. The conference venue is the newly renovated Turku City Theatre, situated in the beautiful city center, alongside the Aura River.


Extended deadline for abstract submission: 8 February 2019

For more information: click here


Workshop to define a Fire Safety Mission for Europe- 3rd December 2018

Although great strides have been made in reducing the negative impacts of fire over the past few decades, the global impact of fire remains staggering. The World Health Organization (WHO) estimates global burn deaths to 180,000 annually, the vast majority of these in low and middle-income countries. Within Europe, more than 3,500 people are killed annually. In most developed countries the cost of fire damage is estimated to be at least 1% of the Gross Domestic Product (GDP). Something must be done to facilitate substantial reduction in these losses and significantly increase societal health, safety, and welfare. To better characterize the problems and develop solutions, fire safety science and engineering research needs to be integrated into societally-transformative risk mitigation and resiliency initiatives. An holistic, society-focused Fire Safety Mission is needed.


In June of this year, the European Commission published the outline for “Horizon Europe”, the research & innovation programme which will follow Horizon 2020, with a proposed budget of around 100 billion € for 2021-2028. The published text makes no mention of fire safety. The proposed structure will build on Thematic “pillars” and horizontal “missions”. The definition of a “Fire Safety Mission” is particularly suitable for the inclusion of fire safety in Horizon Europe, as fire safety is truly horizontal in nature, cutting across a broad variety of potential themes.

The International Association of Fire Safety Science (IAFSS) recently launched a position paper calling for action concerning fire research and engineering needs for the future, The IAFSS Agenda 2030 for a Fire Safe World. Using the IAFSS Agenda 2030 as a starting point for dialogue, the IAFSS and ISO TC92 would like to invite all fire safety stakeholders to a workshop to define a Fire Safety Mission for Europe.

The meeting will be hosted in the CEN/CENELEC buildings in central Brussels so space is limited. This event is for registered participants only. Registration is free, but the organizers reserve the right to charge a no-show fee for registration without participation. The tentative workshop agenda is below.

Workshop Agenda, 10:00-16:00, Monday, 3rd December 2018

09.00 – 10.00 Registration

10.00-10.10 Welcome and Introductions (Margaret McNamee, LTH)
10.10-10.20 Why fire safety is important in tomorrow’s world (Patrick van Hees, LTH, Chair IAFSS and ISO TC92)
10.20-10.40 Lessons Learned from Fire Research in H2020, the example of wildfire research (DG RTD, Nicolas Faivre)

10.40-11.00 Fire Information Exchange Platform (DG GROW, Georgios Katsarakis)
11.00-11.20 What do we mean by Missions in Horizon Europe? (DG RTD, Neville Reeve)

11.20-11.40 Coffee

Funding Agency: “Brandforsk – fostering safety through dedicated research funding”, Björn Sundström, Chairman of the Board, Brandforsk
Fire Fighter: Pieter Maes, Brussels Fire Department
Fire Engineer: Brian Meacham, President-Elect, Society of Fire Protection Engineers, SFPE
Academia: “Fire Science: funding of research for citizen safety”, Guillermo Rein, Imperial College
Industry: Jonathan Crozier, pinfa and Quentin de Hults, Modern Building Alliance (MBA)

12.30-13.00 Questions and Panel Discussion

13.00-13.45 Light Lunch

13.45-14.00 Introduction to Afternoon Breakout Sessions
14.00-15.00 Roundtable workshop to define possible Fire Safety Mission for Horizon Europe

FINAL PLENARY SESSION (Moderator: Kristin Sukalac, Prospero)
15.00-15.50 Summary report key points from breakout table discussions
15.50-16.00 CONCLUSIONS and WHAT’S NEXT? (Patrick van Hees, LTH)

As we get closer to the date of the Workshop, additional information may be posted, and registrants may receive additional information by email. Thank you for your interest in this important initiative, and we look forward to seeing you in Brussels in December!

If you have any queries, please do not hesitate to contact us at margaret.mcnamee@brand.lth.se



The IAFSS would like to thank the following sponsors for making this meeting possible:

Brandforsk, Kingspan, The Modern Building Alliance, The National Fire Protection Association (NFPA), pinfa, Rockwool and The Society of Fire Protection Engineers (SFPE).

Workshop: Towards flame retardant biopolymers and biocomposites

C2MA (Centre des Matériaux des Mines d’Alès) part of IMT (Institut Mines-Télécom), Alès and EPNOE (European Polysaccharide Network of Excellence) are organizing a workshop entitled “Towards flame retardant biopolymers and biocomposites: current research strategies, scientific barriers and perspective applications”.


This workshop is a unique opportunity to gather experts in flame retardant technology and specialists in polymers and composites based on bioresources. These two communities will be brought together to enable them to work more closely. The replacement of oil-based materials by bio-based ones is one of the main trends driving the development of innovative functional materials. This leads to new challenges which need to be overcome: Which bioresources and building blocks are available to develop flame retardants from bio-based materials? Which synthesis and functionalization strategies are required? How to improve the flame retardancy of biobased materials such as, for example, natural fibres which are already used as reinforcements in composite materials?

This meeting aims to review the existing knowledge, share ideas and envisage new strategies enabling the improvement of the thermal and fire retardant behavior of biobased materials and/or to develop biobased flame retardant additives through biomimetic approaches. It is expected that the workshop will foster collaborative projects between academics and industry.


A review of fire growth and fully developed fires in railcars

First published: 17 April 2018 in Fire and Materials

A literature review was performed to assess the state of knowledge of the effects of railcar interior finish materials on fire growth and fully developed fires from railcars. An overview is provided on standards and requirements currently used to regulate interior finish materials. Following this review, an overview of experimental and computational research is provided on railcar interior finish flammability and its impact on fire growth. A survey of the research on fully developed fires and the potential heat release rates of railcars is then presented. This includes scaling laws, experimental research, and model development. Future research recommendations are then presented.


Studies on intumescent flame retardant polypropylene composites based on biodegradable wheat straw

Published in Fire and Materials: 18 April 2018



Wheat straw (WS) has numerous advantages compared with traditional bioadditives such as starch and lignin. So in this work, based on WS and silica microencapsulated ammonium polyphosphate, flame retardant polypropylene/wheat straw (WSP) composites were prepared by melted blend method. Flame retardant and thermal properties of WSP composites have been investigated. The results of cone calorimeter show that peaks of heat release rate and total heat release of the flame retardant WSP composite decrease substantially compared with those of pure polypropylene. The peak of heat release rate value of the flame retardant WSP composite decreases from 1290.5 to 247.9 kW/m2, and the total heat release value decreases from 119.4 to 46.3 MJ/m2. Meanwhile, thermal degradation and gas products of the flame retardant WSP composite were monitored by thermogravimetric analysis and thermogravimetric analysis‐infrared spectrometry. The result of thermal analysis shows that the flame retardant WSP composite has a high thermal stability and has a 30.0 wt% residual char at 600°C. From this work, we hope to provide a method to prepare flame retardant polymer composites with a biodegradable natural material‐WS.


Response by Dr. Alexander Morgan to “Flame retardants in UK furniture increase smoke toxicity more than they reduce fire growth rate”

Response by Dr. Alexander Morgan to “Flame retardants in UK furniture increase smoke toxicity more than they reduce fire growth rate” Chemosphere 2018, 196, 429-439

Dear I recently read an article related to flame retardant use with a title that I find incorrect. Given the publicity the article is receiving, I feel a need to comment on it. While there are parts of the paper I find to be done carefully, and I agree with, there are some fundamental flaws in the paper’s experiments that do not support the title. Indeed, I believe some results in the paper show that the flame retardants are working as intended and do actually reduce fire growth rate when tested against the ignition source they were designed to protect against. A better title for the paper would be “Flame Retardants in UK Furniture Can be Overwhelmed by Stronger Fire Sources and May Not Address All Fire Hazards”.

First, let me comment on the parts of the paper with which I agree. I do believe that fire safety regulations should change as we discover new fire hazard scenarios, or discover data that suggests the approach should change. There have been numerous studies showing that heat release is the most important consideration in enabling escape from a burning room, and those studies show that heat release causes a high number of deaths, probably more so than toxic gases. However, for those who cannot easily escape a burning room (very young, disabled, very old), I suspect toxic gases can be equally lethal, if not more so, than the heat release issue. So, in that aspect, I agree with the authors that smoke toxicity is something worth considering in fire safe material development, and is probably something that we as fire safety scientists should take a look at and try to develop fire safe materials that lower heat release and toxic gas emissions. Materials that inherently char and have inherently low heat release are capable of doing both, but they’re currently relegated to high performance (high cost) applications such as aircraft and passenger train cars. I also agree with the authors that halogenated flame retardants, due to how they work in a flame, will create more non-combusted products and more smoke. This is very well known and not a surprise. However, if the sample never ignites, then much of these smoke and toxic gas issues go away. I’ll return to this point later in my discussion, as this is important to understand regarding the full-scale experiments the authors conducted. Further, I agree with the cone calorimeter (bench scale tests) experiments that the authors carried out, in which they made miniature furniture assemblies of padding and surface fabrics to see how the combined system behaved when exposed to a forced combustion fire hazard scenario. Indeed, testing of combined foam and fabric systems is more relevant to real world fire behavior because it is how everything works together in a fire, not the individual components, that matters.

The results from the cone calorimeter tests show, not surprisingly, that the highly flame retarded material has the lowest heat release out of all systems tested (a good thing), while having the 2nd highest amount of CO released and 2nd highest amount of HCN released (not a good thing). But for the reasons I described above, this is expected – flame retardants inhibit combustion, so one should expect to see higher amounts of incomplete combustion products. The less flame retardant present, the hotter the potential flame from polyurethane, and therefore the flames get hot enough to start burning up some of the toxicants. By cone calorimeter data alone, we are presented with an interesting finding: heat release is lowered, so flame growth is lowered, but the tradeoff is an increase in toxic gases. Not surprising to those of us in the field, but certainly a sign that we must work toward a better performance: equally low heat release/reduced flame growth rate, and lowered smoke toxicity.

I do have some questions on how the authors collected their gases from the cone calorimeter, as I know from personal experience this isn’t easy. I did not see enough details in the experimental section to answer my questions, but I’ll trust the authors cleaned out their ductwork between runs and had the necessary heated transfer lines to collect emissions at the right place in the cone calorimeter exhaust system. One final comment that the authors touch on, but don’t really drive home, is about some of the flame retardants used in this study. While the authors expressed surprise that decabromodiphenyl ether was found in the products, when it was thought to be absent from the market, this should have been a call for more product inspections on imports to the United Kingdom (UK). I feel strongly that as chemicals are found to have negative persistence, bioaccumulation, and toxicity data, they should be removed from use, and we should enforce those regulations that require them to be removed from use. There are better fire safe materials to use which provide meaningful fire safety and minimize environmental impact.

When looking at the large-scale tests, however, I find experiments that are not reproducible. Further, the results appear to have artifacts of the actual experimental conditions and are not relevant to real world conditions. Finally, the large-scale experiments, by the authors’ own admissions, use an ignition source stronger than that called for in the UK legislation. This is an important point from a fire safety perspective and undermines the authors’ arguments that flame retardants increase smoke toxicity more than they reduce fire growth rate. Let me walk through the full-scale experiment and the problems with it that make the title misleading.

First, the authors used a modified shipping container as the “room” in which to conduct their tests. I believe there are numerous labs throughout the European Union that could have provided a standard ISO room for fire testing, to understand how the fire grew and to control the air flow rates, which would in turn affect the fuel/air mixtures and toxic gases/smoke released. A shipping container is not a representative space for mattress use. I suppose people could live in shipping containers, but I would think they are the minority in the UK, and so the shape of the container and how or whether the steel walls affected heating of the room isn’t considered in this analysis either.

The authors state that for their testing setup “The outlet was twice the area of the inlet so that only cool air flowed into the container through the inlet, and only hot effluent left through the outlet.” The authors state later in their paper that they did not directly measure gas temperatures going into and out of their modified shipping container, but instead assumed them from another paper they cited. Given the nature of their setup, this should have been validated with actual measurements. But more importantly, the authors indicate in their paper: “Reasonable reproducibility was obtained for each pair of apparently identical mattresses, despite the different weather conditions and wind directions on the day of each test. The UKFR1 and CHFR1 tests were the only two tests performed on the first day, in significantly windier and wetter conditions; visual observation showed the wind moving the crib flame away from the back of the sofa on the first two tests; they showed longer ignition delay times than the subsequent tests where calmer, more stable weather conditions prevailed, until the end of the test programme.” Humidity is well known to affect fire growth and smoke emissions, as are air flow rates and air temperature. This is why controlled rooms are used: to see heat release and emissions properly, as a function of controlled conditions which would be relevant to actual fire hazard scenarios. The conditions in this experiment are uncontrolled, and therefore do not produce reliable conclusions. This is why there are both ASTM and ISO standards regarding room burn tests, to ensure one is testing a representative room under controlled conditions, with artifacts removed.

Second, there is the issue of the ignition sources used in the large-scale test. The authors tried igniting all 4 of their mattress compositions with the “No. 5 crib”, which is the wooden ignition source currently used in UK regulations. This regulation tests individual components, not composite systems of foam and fabric, so it has its limits. Very interestingly, the authors found that none of the samples could be ignited by the No. 5 crib ignition source, and therefore, there would be no toxic smoke, or than the small amount generated by the wood crib. However, due to the above issues with the uncontrolled room, one wonders if any of the samples would have ignited with the No. 5 crib ignition source, thus changing the outcome and conclusions of the paper. Had the flame retarded samples resisted ignition and the non-flame retarded samples ignited, that would tell us that the flame retardants did reduce fire growth rate. If, in a controlled room, none of the samples ignited with the No. 5 crib source, that would tell us that the existing UK test is only appropriate for protecting against fire on exposed polyurethane foam, and is not appropriate for real world furniture composed of foam and fabric assemblies. The authors further muddled the conclusions of this paper by moving to a No.7 wooden crib source, which has a much higher intensity fuel load (125 g of wood to burn, vs. 17 g for the No. 5 wooden crib), to get the samples to ignite. Now the authors have forced the samples to burn, against a more rigorous fire source, in uncontrolled conditions, thereby moving outside the existing fire hazard scenario that the UK regulations address. I would suggest that the failure of the No. 5 crib to ignite these mattresses proves that (a) the large-scale experiments are not controlled or meaningful and conclusions from them cannot be relied upon; and (b) maybe the real issue here is that the existing UK standard should be testing against composites, rather than single components, to provide meaningful fire safety. But we do have to ask ourselves what we are trying to protect against when we design fire safe materials. One cannot provide fire protection against every fire hazard scenario out there. Where would we stop in fire protection for furniture? Crib 7? Flamethrower? Arson (can of gasoline)? Just because I can force a flame retarded material to burn by overwhelming it doesn’t mean that it provides no benefit at all, as the title of the paper suggests. The authors in the introduction touch on the flaws of the existing BS5852 test, and perhaps that should have been the focus of their work: showing that composite materials of foam and fabric are more meaningful for study than testing individual components. If the statistics in the paper pointed to the need to test against large fire sources, then I think testing with a No. 7 crib would have been meaningful – again if it had been done in a controlled room.

To conclude, the title is not supported by the data because the full-scale experiments are not reliable. Further, the title is misleading and is exactly the sort of title that undermines the credibility of scientists everywhere. It’s attention grabbing, but not supported by the data, thus confusing the public and making them distrustful of our work. The conclusions from the cone calorimeter data are sound, as is the concept of testing actual mattresses of known composition, but the work should be withdrawn, re-tested under controlled conditions, and presented again.

Speaking philosophically about the paper and what I believe was its desired goal, I have to ask the question: does it make sense to ask for both improved fire protection AND low emission toxicity? If the material never ignites against an ignition source found to be meaningful from a fire hazard perspective, then emissions are not a problem. But if we have a goal as a society to protect all people against all fire threats, then we need to look at all aspects of the problem, including the fire test and the cost/benefit analysis of making changes. If we achieve better fire safety, but most people cannot afford it, we’ve headed in the wrong direction. I personally would like to see inherently low heat release char forming materials used more often since this would concurrently address fire and emission toxicity issues, but I do not think the market will accept or bear the costs of aviation-grade materials replacing commodity goods in our homes. Maybe in the future the price of these materials will come down, but they’re not there yet. I further have no issue with more natural materials being used. My own analysis suggests that many natural materials can have lower inherent flammability than some synthetics. But synthetics have their place as well, and it’s not my place to tell society what they can and cannot use. Society (government, civilians, and scientists combined) must decide what level of fire risk it can live with, and once that is decided, then I as a fire safety scientist can run the right experiments to find out whether existing solutions work. This paper isn’t the right way to go about it. It addresses about half of the scientific problem, but then falls short due to the failure of the full-scale experiments. Let’s get the data in a controlled manner and see what it says, and then make conclusions about whether current flame retardant approaches are appropriate for future use.

Alexander B. Morgan, Ph.D. – Dayton, OH USA

Dr. Morgan is a fire safety scientist with 22 years of experience. He is a Group Leader at the University of Dayton Research Institute (UDRI) and the Editor-in-Chief of the Journal of Fire Sciences (JFS). This editorial represents his opinion and not those of UDRI or of JFS.

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