some neglected areas in fire safety engineering vyto babrauskas.pdf · 1988: sfpe, sfpe handbook of...

Some neglected areas in fire safety engineering

Dr. Vytenis (Vyto) Babrauskas Fire Science and Technology Inc.

Issaquah, WA

USA

A little bit about your speaker

I am probably best known for these things:

Inventing the Cone Calorimeter.

Studying furniture fires, along with inventing the furniture calorimeter.

Writing the Ignition Handbook (the largest book in the fire safety area ever written by a single individual).

Scientific study of electrical fires.

So I will talk about none of these things today!

Instead, I will try to look at some issues in our field that have not received much attention, yet they should.

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A personal perspective

I have been in the fire safety science field since 1972, which was almost the beginning of fire safety science in the US.

Fire safety science in the US only started about 1970, when the National Science Foundation first funded a series of large research projects.

In a few other countries, it started earlier.

Around 1945 in the UK (at the Fire Research Station)

In the early 1960s in Japan

In the late 1960s in Sweden.

Thus, it is roughly correct to say that the fire safety science field is about 40 years old.

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Focus of this talk

I will briefly assess where we are at the moment, from the point of view of positive achievements.

But the bulk of the talk will be on areas of omission, since this is where progress needs to be made.

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Some major positive highlights

Look at the books, to judge the science:

Prior to 1972: only “technology” books, not “science” books existed.

Starting in 1972, science books started to appear.

1972: T.T. Lie, Fire and Buildings (a small book; you probably have never seen it).

1985: D.D. Drysdale, An Introduction to Fire Dynamics (first edition).

1988: SFPE, SFPE Handbook of Fire Protection Engineering (first edition).

• This was a remarkable achievement and an indication that we now had a real science.

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Thermostructural design…

This is a very interesting area.

T.T. Lie’s book already mentions it in 1972, but of course he was discussing analytical methods, not computer methods.

Yet in 1972 at Berkeley, Prof. Boris Bresler and his graduate student Bob Iding had already started developing two computer codes for thermostructural modeling.

Bresler already understood in the mid-1970s the importance of frame action on the fire response of high-rise buildings, something ignored by the rest of the profession for decades after that.

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…Thermostructural design

Up through about 2000, I was repeatedly pointing out that Bresler’s early work was completely forgotten, and that the profession has chosen to ignore the science aspects of fire resistance, continuing simply to test by 100-year old test methods.

But over the last decade, a remarkable change occurred here, and there is now a large number of engineers who work in this area.

There are periodic Structures in Fire (SiF) conferences, and even a new journal, Journal of Structural Fire Engineering, appeared in 2010, albeit from a tiny publisher.

Even the US now has engineers working in this area, although most of the interest is in Europe.

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Progress over 40 years

It is remarkable how much progress has been made over a 40-year period.

We should all feel good about that.

But today I want to focus on a few areas where more efforts are still needed.

First, though, I will note some “mixed-success areas”.

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Areas of mixed success…

There are two important areas where I consider that success has been decidedly mixed.

Fire modeling

Performance-based building codes.

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Fire modeling

Fire modeling has shown both great strengths and significant limitations.

I will not talk about this today, since I have published 3 papers on this topic (1996, 1999, and 2007).

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Performance-based building codes

Again, I have written extensively on this topic, and I will not review it here today.

The basic problem with almost all these codes is that impartial, clear-cut systems are replaced by systems where persons in charge are given almost complete, arbitrary freedom to make any kind of decision they want, subjected to no useful checks-and-balances.

In almost all cases, this means levels of safety will drop.

I am not arguing that levels of safety (along with their costs!) should remain high, but I think any lowering of safety levels should be uniformly applied, not the outcome of an official’s ad hoc decisions.

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Some areas of not much progress

I will focus on 5 areas where I feel that the progress made to date is still poor.

① Learning from fire incidents in a systematic way;

② Studying fires in residential houses;

③ Collecting statistics which are meaningful;

④ Developing cost-effective codes and standards;

⑤ Considering the unintended consequences of fire safety provisions.

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Learning from fire incidents in a systematic way…

Fire safety engineering (FSE) is an applied profession.

To be competent, it has to have a strong science and research base, but nonetheless it must respond to fires in a realistic and rational way.

The only way to do this is to have good knowledge about real fires that occur. This means to do a good fire investigation.

Two basic requirements:

The investigator must be skilled.

The results must be disseminated.

I will now make some detailed comments based on my experience as an American, so they will refer to the US situation.

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…Learning from fires…

Almost any significant fire gets investigated by two investigators: a fire department investigator, and an insurance investigator.

There are around 8000 fire investigators in the US

But we see almost no benefit from this.

The standards for fire investigators are not high

This is mostly a problem with fire departments. Some of them have good personnel, but many do not.

The big problem is that the results are not disseminated, so we never learn from fires.

I am one of the small number of persons who do learn, since I am a forensic expert, and so I get to see court documents.

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Why is the information in fire investigation reports not available?

Must look separately into fire departments and insurance companies.

Fire department reports are ostensibly available to the public.

• But they are not published and you would have to demand to see them individually from each department.

• Summary statistics do get reported to the NFIRS statistical data base, but we shall see its problems later.

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Insurance company reports are completely secret (apart from those that have to be revealed to a court if there is a trial).

This is a very poor policy. Society does not get to learn anything from its problems.

Until about 15 years ago, NFPA used to operate a fire investigation department. These investigators used to go to major fires and write a good, long report. They would also publish a shorter version in the NFPA Fire Journal.

This all ceased, and there is now no magazine where you can read about fires that were investigated.

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…Learning from fires

The foundation of any science is the systematic collection of data.

In the case of fire safety science or engineering, obviously the most important data are the data on actual fires. If no means exist for doing this, then sound underpinnings of the science are missing.

What is very disappointing here is that the profession had better resources in this area in the 1990s than it does today.

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Studying fires in residential houses…

In the US:

97% of fire deaths in buildings occur in residences,

3% in all other types of buildings.

About 1% of the residential fire deaths are in high-rise buildings.

There are generally zero deaths in high-rise office buildings.

The above statistics refer to building fires; out of the total fire deaths, vehicle fires account for around 20%.

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…Residential houses…

Concerning high-rise building fires:

Must distinguish the US, versus “developing countries” situation.

In the US, about 50% of high-rise buildings are sprinklered and strict building codes prevent the use of interior finishes prone to rapid fire spread. The experience is clearly different in less well developed countries, where spectacular high-rise building fires still keep occurring.

But most of the US research dollars are spent on studying fires in commercial, industrial, or high-rise buildings.

Understandable, if insurance company money is involved; unfortunate if public funds are spent.

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Most glaring problem concerns human factors and evacuation studies.

Countless studies have been done looking to see how people march down the stairs in high-rise buildings.

This is not helping anyone avoid deaths from fire!

Even 100 years ago, capacity of stairways was generally not the problem.

Then, people would die due to chained-shut exit doors, or lack of timely warning. This is still largely true today.

Studying exit drills with stop watches does nothing to remove illegal chains!

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There have been very few studies on how people die in house fires, yet this is 97% of the problem!

You cannot solve a problem if you put your resources into where the problem is not, as opposed to where it actually is.

My own belief is that this situation is largely due to the fear by public officials of adverse publicity.

If the news media reports that “a father, mother, and two children died in a house fire today,” the story is generally limited in its impact. I believe the officials are afraid that, potentially, there could be story about 4 people dying on the 50th floor of some high-rise building, and it would create the impression that they have not been doing their job, whereas the house fire outcome seems not to reflect badly on their job.

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Papers from the Human Behaviour in Fire Symposia

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Houses Other Total % houses

1st: 1998 6 74 80 7.5

2nd

: 2001 6 50 56 10.7

3rd

: 2004 13 37 50 26.0

4th

: 2009 6 62 68 8.8

5th

: 2012 4 57 61 6.6

Total 35 280 315 11.1

…Residential houses

Policeman finds a drunk stumbling under a street lamp, looking for something on the ground.

Policeman: What are you doing?

Drunk: Looking for my keys.

Policeman: Where did you lose them?

Drunk: In the bushes, over there.

Policeman: Then why are you looking for them under the street lamp?

Drunk: Because the light is good here.

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Collecting statistics which are meaningful…

What would we want to know from fire statistics? In my view, answers to these questions are the most important:

How did the fire start?

How were the occupants alerted?

How did the occupants cope?

How many persons died, were seriously injured, or non-seriously injured?

How effective was the fire department?

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…Meaningful statistics…

How did the fire start?

The US NFIRS statistics are quite poor here.

Only input into the data base is from the firefighters.

Firefighters are normally interested to find out only if arson was committed.

But insurance companies hire investigators who do make a detailed investigation.

Yet the system has no provision for these insurance company findings to enter into the data base.

Especially a problem for electrical fires.

• Fire departments lack electrical experts, while private fire investigators often bring an electrical engineer.

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How were the occupants alerted?

The type of smoke detectors that were installed. The question is not asked.

Did the smoke detector alert the occupants, or did they learn of the fire by other means? Question is not asked.

In my experience, fire departments often do not treat the whole smoke detector issue carefully.

• Commonly they will just write down “Did not find any detectors, although the occupants told us they had them.”

• This question should be answerable by doing a better investigation.

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How did the occupants cope?

This is a crucial question!!!

Prof. John Bryan (Univ. Maryland) and Bud Levin (NIST) studied this in the 1970s and 80s.

Their studies attempted to identify and tabulate the actual behaviors and activities of occupants.

But this kind of study has been largely abandoned, and the profession currently seems to be largely content with “moving marbles” types of evacuation models.

Active research is essentially nil.

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Behavior in house fires…

My own forensic experience is that it is very common for residents to die in house fires not because the fire was too rapid for them to cope, or they failed to awake (although ionization detectors must be strongly discouraged as a means of waking people from smoldering fires).

Instead, occupants are awake, aware of the fire, yet engage in counter-productive behavior.

A recent example from a case I am currently working on:

There is a 911 call from the mother in the house, who says her couch is on fire. She also is trying to put the fire out. …

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…Behavior in house fires…

Neighbor across the street sees fire through the open front door, and hears the mother and her 5-year old son running around and shouting.

She then sees the front door being slammed shut, but there is still shouting.

When the fire department arrives, there are two dead people and water is running from the kitchen faucet.

I have also encountered numerous instances where a person is badly injured or dies, since he tried to take out from the house a burning chair, mattress, Christmas tree, etc.

These are almost always men. Women seem to be smarter.

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…Behavior in house fires

It should be possible to reduce such fire fatalities by properly focused education efforts.

But there is very little progress in this area.

In the 5 symposia I examined, there were zero papers giving ideas how to make suitable teachings.

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How many persons died, were seriously injured, or non-seriously injured?

The dead victims are probably tallied fairly accurately.

But “injured” is a meaningless concept.

• Victims could have a sprained ankle, or 3rd degree burns over 50% of their body. Both are “injured”.

• Some refinement needs to be developed.

Is HCN toxicity important?

Question was raised in the 1980s, but research abandoned and no good answers.

Some people think it may be the #2 factor, after CO.

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…Meaningful statistics

How effective was the fire department?

Important questions are not asked, or not asked well.

• How long after the alarm was received, was there water first put on the fire?

• What was the dollar loss? This question is asked, but not asked well and very poor answers are obtained.

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Developing cost-effective codes and standards…

In no country that I am aware of, are building code provisions considered on a cost/benefit basis.

Yet, this is the only legitimate basis for making economic decisions in a society.

Code change provisions are usually driven by manufacturers who stand to gain income if new, more severe provisions, are enacted.

The cost to the public, versus the benefit, is never quantified.

Existing provisions are almost never reexamined.

Fire safety provisions are among the worst for being onerous and often lacking a demonstrated technical effectiveness and cost-effectiveness.

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…Cost-effective codes

In the last 25 years, a number of countries went through a process to develop performance-based codes.

This should have been an ideal opportunity to reformulate the regulations from a cost-effectiveness viewpoint.

Yet, I know of no country were this was actually done.

Furthermore, I remain extremely critical of the technical quality (incompetence) of the performance-based codes, but I have already written at length about this earlier.

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Considering the unintended consequences of fire safety provisions…

This is a huge topic and we could spend all day talking about it. So this has to be just a very brief overview.

I seem to be one of the very few persons in my profession who is not afraid to tackle this topic.

But I hope this situation will change, since I believe that, first and foremost, one’s civic duty is to be a good citizen of Planet Earth. Loyalty to your profession should not stand in the way of being such a good citizen.

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…Unintended consequences…

Essential principle: In good social policy, there is a proper balance between health and safety.

Ideally, health and safety requirements would never conflict.

But, while health provisions almost never diminish safety, the converse has not been true!

The fire safety profession has traditionally been narrowly focused and taken the stance that dealing with health issues is someone else’s job and that fire safety professionals are free to adopt any and all fire safety measures without fully considering potential harm to health.

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The big picture: What to do if safety and health provisions conflict?

This can only properly be answered by making a global economic assessment.

If a fire safety measure is likely to introduce a certain amount of health harm (human injury or death; injury to animals, plants, or a viable biosphere), then the overall benefit/harm economics have to be quantified.

This, of course, will not be done if fire safety professionals are too much influenced by manufacturing interests.

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Some sad history

Asbestos

Carbon tetrachloride

Polychlorinated biphenyls (PCBs)

Freon

Halons

Halogenated organic FR chemicals (PBDEs, tris, etc.)

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Asbestos

For many, many years, asbestos was a ‘wonder tool’ of the FSE profession.

Often, simply adding asbestos to just about anything was seen as a good solution.

Now of course it not only is an embarrassment, but, in the US, led to essentially every building product manufacturing who ever used it in their products, even to a limited extent, into going bankruptcy due to lawsuits against asbestos.

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Carbon tetrachloride

Carbon tetrachloride was widely used as a fire extinguisher, even in people’s homes.

It is indeed very effective in stopping chain-branching combustion reactions.

However, the toxicity was eventually recognized and it became a substance limited to industrial uses where personnel exposure is carefully controlled.

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Polychlorinated biphenyls (PCBs)

These were considered the best transformer fluids, of the highest fire safety, ever invented.

Toxic effects were already known by 1937.

Yet production continued until the late 1970s.

As late as the 1960s, the industry lobbied to increase the use of PCBs.

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Freon

This family of chemical compounds was considered to be the ideal refrigerant when it was invented in 1928.

Its main advantage was that it is non-combustible and consequently it was used as a solvent, in addition to use as a refrigerant medium.

Not directly toxic to humans, but an ozone-depleting chemical, which could destroy life in our biosphere.

Banned by the Montreal Protocol in 1989.

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Halon fire extinguishing agents

Very similar story as for Freon, but Halon chemicals were used specifically for fire suppression.

Banned by the Montreal Protocol in 1989.

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Halogenated organic FR chemicals

This is the latest sad story in the profession.

This family comprises chemicals which are mutagens, carcinogens, and/or endocrine or reproduction system disruptive agents.

First came into news in 1977 when Arlene Blum and Bruce Ames identified tris-(2,3-dibromopropyl) phosphate, TDBPP, as a mutagen. This chemical was being put into children’s pyjamas. As a consequence of their article, the chemical was removed from children’s clothing.

But manufacturers substituted tris-(1,3-dichloro-2-propyl) phosphate, TDCPP, which has the same problems. …

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Based on Blum and Ames work, TDCPP was then also removed from children’s sleepwear.

But it was not banned by the government, and manufacturers started putting it into polyurethane foams for furniture, where it is still used for this purpose.

FR chemicals started being put into furniture foams from 1975, due to California regulations.

The California regulation was counterproductive, since it did not improve fire safety of furniture, yet ended up encouraging toxic chemicals to be put into foams.

Together with Dr Blum and two coauthors, I presented a detailed paper on this at the 2011 IAFSS Symposium.

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US regulations against toxic chemicals are notoriously ineffective, due to lobbying efforts of the chemical industry.

US has not even signed the Stockholm convention, which is law in 178 other countries on the planet.

Halogenated organic FR chemicals for plastics have been highly promoted by their manufacturers, but based on distortions of science.

It has been personally distressing to me that much of the industry’s advertising has focused on a 1988 study that I led while I was at NIST. …

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My 1988 NIST study was essentially intended as a revisiting of Hillenbrand’s 1973 study.

Hillenbrand’s title makes its scope clear: A Full-Scale Fire Program to Evaluate New Furnishings and Textile Materials Developed by the National Aeronautics and Space Administration.

Both Hillenbrand and I found that FR chemicals can be high effective if:

①They are used in high concentrations;

②All of the combustibles in the room are FR treated.

Neither of these prerequisites will be true except for products used by NASA, or some other safety-focused institutions.

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Halogenated organic FR chemicals are ineffective if:

The loadings are low; or

Attacking flames of sizable volume can be expected.

But these are precisely the conditions that will hold in residential houses.

Yet, there is health harm even from the low loadings of the FR chemicals found in consumer products.

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In some cases, it is easy to do a balance of fire safety benefits, vs. harm to health. Those are the cases where there is zero fire safety benefit.

I and some colleagues of mine have studied two such situations:

FR chemicals in domestic upholstered furniture foams.

FR chemicals in plastic foams used for thermal insulation (these are very hazardous even if they have

residential levels of FRs and must be protected by

thermal barriers, in which case they are acceptable).

In both cases, amount of chemicals used is insufficient to produce a fire safety benefit.

Yet, harm both to people and the environment is known.

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Firefighter health

In recent years, it has become evident that firefighters are experiencing much greater rates of certain kinds of cancers, than is the general population.

It appears this is due to formation of dioxin and furan compounds from pyrolyzing or burning plastics containing halogenated organic FRs.

Proponents of the FR chemicals (Zaikov & Lomakin) are on record that dioxins are “the most toxic family of chemicals ever studied.”

It is exceedingly poor social policy that firefighters should be getting injured by chemicals introduced for an ostensible fire safety benefit.

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…Message

I leave you with the message that is always taught to first-year medical students: Primum, non nocere (“First, do no harm”).

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Final note

What am I doing in the future?

I will remain active in the forensic science aspects of fire safety science.

I am writing a new book, Electrical Fires and Explosions, which will be the first book to look at these topics from a science-based point of view.

• If you encounter any interesting electrical fires and obtain some photographs that have a good educational value, please share them with me; I would like to book to be as well illustrated as possible.

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The end

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some neglected areas in fire safety engineering vyto babrauskas.pdf · 1988: sfpe, sfpe handbook of...

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