NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

4215101 May 5, 1966 9307

Fire Protection

Materials and Structures

by

J. V, Ryan

NOT FOR PUBLICATION

Prepared for distribution at

46th Annual Meeting of

The Society of American Military Engineers

May 23, 1966

National Bureau of Standards

Gaithersburg, Maryland

IMPORTANT NOTICE NATIONAL BUREAU 01

for use within the Governm

and review. For this reaso whole or in part, is not a Bureau of Standards, Was

the Report has been specif

Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015.

rogress accounting documents intended

it is subjected to additional evaluation

ature listing of this Report, either in n the Office of the Director, National

r, by the Government agency for which

nal copies for its own use.

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

Fire Protection

Materials and Structures

J . V . Ryan

ABSTRACT

Fire Protection covers all efforts to safeguard life

and property from the harmful effects of unwanted fires.

It includes systems for extinguishing fires once started,

confining fires, and early detection. It also includes

activities in the area of prevention, such as the gatherand dissemination of information on ignition, growth and

spread, flammability, smoke and toxicity, etc. Only

through better knowledge and understanding of these phenomena can effective, efficient, and economical prevention

be practiced.

The advancement of fire protection is made through

basic studies to increase understanding of the related

phenomena; through application of this understanding in

preparation of new or improved test methods, design

practices, performance criteria, and regulations; and

through the development of materials, systems, and structures to implement the intent of the regulations and

criteria

.

The National Bureau of Standards has been active in

fire research and fire protection for half a century.

They have worked in nearly all related areas except the

development of new materials or equipment for fire protection. However, their work has been instrumental in improving the Nation's capability for measurement of such

developments against appropriate criteria.

Fire Protection - Materials and Structures

By

J . V . Ryan

1. INTRODUCTION

The protection of life and property from the effects of unwanted fires

is the ultimate application of the work of many people in government, industry, universities, and societies. These include fire fighters, materials

and equipment manufacturers, research workers and others.

The testing of building elements for fire endurance in this country

began in the last years of the nineteenth century. However, structures

had been designed with fire problems in mind at least a century earlier.

In fact, ordinances on fire resistive construction were signed by King John

following the London fire of 1212, three years before he signed the Magna

Charta [l]. Apparently the first ordinance specifically requiring a fire

test in this country was the 1899 New York City 3uilding Code. For a more

detailed history of fire testing, the reader is referred to the paper by

Shoub [2] .

The development and adoption of a test method provides the standard

necessary for the effective implementation of regulations, be they the

regulations of a political jurisdiction or those imposed by the building's

owner in the design process. The average home buyer is not conscious of

fire protection when he tours model homes or sketches out what the family

wants. The concern with fire protection of many owners of commercial

buildings does not extend beyond meeting the code requirements of the

jurisdiction within which they operate. The owner most conscious of fire

protection is the Federal Government. It is not subject to local code

requirements and, therefore, is both free and, as the largest single owner

of buildings in the country, is required to think about the fire protection

desired. This thinking must involve the concept and degree of protection

to be provided, the materials and structures to be used, and the means by

which it is determined that these materials and structures do provide the

desired degree of protection. As a result of this last consideration, the

Government agencies involved in construction--General Services Administration,

Corps of Engineers, Bureau of Yards and Docks, Air Force Office of Construction,

and others--have been active in test method development as well as in en- couraging and supporting N3S in its efforts.

The title of this paper, "Fire Protection - Materials and Structures",

could be subtitled "Of or By?". It is a very pertinent question. Some

groups are concerned with the protection of materials or structures; others

are concerned equally with the protection afforded by the materials or structures employed; many, and particularly the Government, are concerned

with both. In this paper, we will try to touch both the "Of" and the "By".
2

2. FIRE PROTECTION SYSTEMS

Fire protection is provided by several different kinds of systems,

preferably used in combination. In certain instances, a single system

may be adequate. However, none of them are absolutely beyond the

possibility of failure. Therefore, when the risk is serious, several

systems may well be used.

2.1 Detection

Simple detection of a fire does not in itself have any effect on the fire, either as to its extent or severity. A detection system should

be coupled with a mechanism whereby effective countermeasures are brought

into play. The detector may be a watchman, a simple fusible element, or an elaborate complex of electronic and sonic equipment. Yet how many

fires are detected by the observant passerbyl The countermeasures may

be public or private, and may act to extinguish or to confine the fire.

The NBS Fire Research Section over the years has done work on detection

systems for various Government agencies. This ranged from operational

checks on samples of fire call boxes submitted with bids for the District

of Columbia's alarm system to studies of the basic phenomena involved so that detector requirements could be spelled out. A case in point was the

problem of reliable fire detection in the engine spaces of aircraft.

Since most aircraft engine-space extinguishing systems discharge com- pletely in one, or at most two, applications, there is great concern

about possible false alarms. The high speed and often laminar airflow

in these spaces worked against the use of thermocouples or other essentially

point detectors. The presence of red-hot exhaust systems made radiant detectors unreliable. In short, the highly specialized conditions existing

in aircraft engine spaces during flight were such that no one of the

principles-of-detection then employed could be relied upon both to detect

a fire and not to give false alarms. The Fire Research Section made a careful study of such things as the spectrum of flames, flicker and other

characteristics, and how these characteristics were affected by high winds.

The data provided the basis for a report that was a performance standard

for an aircraft engine-space fire detector. The sponsor (U. S. Air Force)

used that report as the basis for contracts with private industry to

develop suitable and reliable detectors.

2.2 Extinguishment

Extinguishment of unwanted fires is accomplished by many means. These

include the work of professional fire companies using water streams, water

fogs, foams, carbon dioxide gas, dry powders, and inerting atmospheres.

Sprinklers and other built-in systems, plus portable "first-aid" equipment employ some of the same extinguishing agents. Most firemen agree
3

that very little of the water in a solid stream is effective. The

development, by industry, of spray and fog nozzles was motivated by

the need to make more efficient and effective use of water supplies.

Industry has sought to develop better extinguishing systems of all

types, either by more effective use of a particular agent or by

development of better agents. The Fire Research Section has sought

a better understanding of the mechanism of extinguishment. Such

knowledge should be useful to industry in its development work.

Water is very effective extinguishing agent for certain fires.

It is believed that the mechanism of extinguishment is that of cooling the combustible fuel below its ignition temperature. Also, solid

sheet of water flowing over a surface would cut off the oxygen supply,

but that is difficult to achieve. Fires in liquid fuels rarely can

be fought effectively with solid streams of water because the fuels

float on the water. There is little thermal contact with the burning

surface and, therefore, little cooling; there is no interference with

the oxygen supply. Water is made more effective against such fires

through the use of fog nozzles, or the use of foaming agents. If

a complete blanket of foam is built up, the outside air is cut off.

Other extinguishing agents found effective against liquid fuel fires

include carbon tetrachloride, chlorobromomethane , carbon dioxide gas,

and the dry powders (most commonly bicarbonate of soda) . The first

of these is almost out of use because of toxicity problems and problems

with extinguisher designs.

For many years it was believed that the mechanism of extinguishment for bicarbonate of soda was that it broke down in the presence of

flames to release carbon dioxide gas which put out the fire. The car- bon dioxide was believed to displace oxygen, thereby "inerting" the

fuel -atmosphere mixture, or rendering it noncombustible. But it was observed that large amounts of the powder remained after fires had been

put out. Careful measurements on standard liquid fuel fires showed

the minimum amounts of carbon dioxide gas and of bicarbonate of soda

powder required to put out identical fires. Simple chemical calculations showed that there would not have been enough carbon dioxide gas

if all the bicarbonate broke down. Yet most of the latter was laying

on the ground around the fire pitl This triggered a series of investigations, not yet completed, into the mechanism of extinguishment,

and the mechanism of combustion. It has been shown that the interference in the radiative heat transfer from the flames back to the

liquid fuel reduces the rate of evaporation to an important degree.

However, powders of similar physical properties but dissimilar chemical compositions were found to have quite different effectivenesses.

Present work is aimed at better understanding of the chemical or physical effects of various inhibiting (extinguishing) agents on the

processes of combustion. Points of study are the electron capture

characteristics of the inhibitors and the production of ions in flames,

with and without inhibitors.
4

2,3 Confinement

The overall damage caused by a fire in a building will be less

if it can be confined to the room of origin than if additional parts

of the building become involved. If the room-of-or igin is provided

with built-in effective extinguishment, the time during which the

walls, floors, etc. must confine the fire may be minimal. The actual

time will be a function of many variables such as contents (fire load),

ventilation, and how the contents are distributed or packaged, as well

as the extinguishing system. The time may be somewhat longer if re- liance is placed on nearby fire fighters. If the building is remote

and does not have its own provisions for extinguishment, the time may

well be that required for the total burnout of the rooms' contents.

The time during which a building element can withstand a fire is

known as its fire endurance (or still fire resistance in some quarters)

.

It is measured by procedures spelled out in a test method published

by ASTM [ 3 ], NFPA [ 4 ], and UL L 5 ] . The method calls for exposing a representative test specimen to a standard fire under appropriate

load and restraint. The standard fire is defined by a sequence of

prescribed temperatures (average of several points in the furnace

chamber) at elapsed times [ 3 ] , referred to as the Standard TimeTemperature Curve [6], The specimen is to be as representative of

actual use as possible, as to materials, design, and workmanship.

The conditions of loading and restraint also are to be representative

of expected use. Constructions expected to carry loads in use must

sustain the applied load throughout the test, except that steel columns

or beams may be tested without load if protected by materials not intended to carry load. In that case, they are judged against an average

temperature of 1000°F at one cross-section or a maximum of 1200°F.

Walls and partitions, floors and roofs must not allow the passage of

flames or gases hot enough to ignite cotton waste. Neither may heat

transfer through them be such as to raise the average temperature on the onexposed surface by 250°F or the maximumby 325°F. A separate

test for ceilings under lofts or attics has been used very infrequently.

A hose-stream test for walls or partitions may be made on the fire

endurance specimen or a duplicate exposed for a shorter period.

As indicated in the preceding paragraphs, structural elements

often need protection, and frequently the protection is provided by

materials having comparatively low strengths. Unprotected steel members will loose strength and fail in a few minutes [7, 8] . The same members have been protected by materials such that the resulting systems

exhibited fire endurances of several hours in actual tests. Sprinklers

have been used also as protection for bare structural steel systems.

Unprotected wood ignites and burns but continues to support design loads

until well charred. With heavy timber construction, this may be for a
5

significant time[7, 9]. Conventional wood frame construction can be

protected so that the resulting assembly has two hours fire endurance

[9, 10, 11] although some building code provisions limit ratings of

assemblies containing combustibles to a maximum of one hour.

The materials used to protect structural elements may be used to encase or otherwise follow the general outlines of columns, beams,

girders, etc., or as a membrane (ceiling or partition) between the

structural system and the potential fire. Commonly used materials usually

have low thermal conductivity, high heat capacity, resistance to thermal

shock, or undergo endothermic changes of state; or exhibit several of

these properties. All must remain in place to continue their protective

functions for meaningful time periods. All should have very little, if

any, combustible content. Mineral and glass fiber or foam insulations

offer low thermal conductivities. Brick and concrete have high heat

capacity, due in part to their high densities. Some bricks, tiles, and

plasters, and especially the ceramics, have good resistance to thermal

shock. The plasters, and to a lesser extent concretes, undergo changes

involving the liberation of water of crystallization. Both the release

of the water, and its subsequent evaporation, are endothermic. These

are but a few of the many fire protective materials, some of which have

several of the desirable properties. Even wood, which ultimately adds

fuel to the fire, has low thermal conductivity. However, it is not

generally considered to be a fire protective material.

Various assemblies of structural and fire protective elements have

been tested, according to the standard test method [3], by recognized

laboratories. The results of these tests have been used by many local

building officials in assigning ratings or approvals for construction

within their respective jurisdictions. However, the many demands on the

time of the local building officials have lead to their increasing

reliance on others, such as central state offices, the model code groups,

or the insurance bureaus for expert advice as to ratings. Through the

latter groups, the expertise of a few is made available to many. This

is accomplished through analysis of very special constructions plus the

publishing of lists of ratings based on actual fire test results. The

lists serve not only as guides to the local official, but also to the

engineer (Government, industry, or private), architect, and building

owner. Some lists are primarily generic, i. e,,they reference constructions in terms of material descriptions (2 x 4 studs, 1/2-in gypsum wallboard, 3.4 lb expanded metal lath, plaster or concrete by mix and aggregate) , and the rating may be assumed to apply to any material complying

with the given description. The description of the specimen and its

component materials frequently includes physical properties and reference

to applicable nationally recognized standards and specifications. Other

ratings lists are primarily proprietary, i. e., they reference constructions in terms of the proprietary materials actually tested, and the

description involves the trade name and manufacturer’s designation. Such
6

a list is published by the Underwriters' Laboratories [ 10] , which

organization also authorizes the labeling of tested products to indicate they are the same as those used to achieve specified ratings.

Of course, for example, proprietary acoustical tile is used, and tested,

under 2x8 joists. Also, the more comprehensive lists include ratings

based on data from all available sources and include both proprietary

assemblies and generic assemblies [7J.

3. Fire Protection Problems

Although the overall goal of fire protection - safety of life and

property - is easily recognized and justified, the full implementation

of fire protection requires adequate understanding of the problems that

are encountered. Research aimed at providing protection is most effective

only when the hazard to be protected against is well known or is studied.

In fact, the program of study of the hazard often produces the protection.

Penicillin was discovered in the course of a general study of the characteristics of bacteria.

The hazards to life and property may be subdivided into areas cor- responding to fields of study into the defenses against fire. The Bureau

has work in progress in some of these areas,

3,1 Ignition

The ignition characteristics of materials are of primary importance

in determining either the hazard they represent or the protection they

can offer. We have all been warned, from childhood, of the danger of the

pile of oily rags in the closet and the old newspapers in the attic.

More recently we have heard of "exploding sweaters." There are two problems

here. One is ease of ignition, when exposed to an outside source, the

other is the problem popularly called "spontaneous ignition." More accurate terms are "self heating" and "self ignition," which have been

defined clearly [6] and are used by technical people in the field.

Self-heating is, as the name implies, the phenomenon whereby a material undergoes temperature increases as a result of exothermic

reactions. The action of bacteria in stored grain, and the setting of

Portland cement are both examples. If the reaction produces only a moderate amount of heat or the material configuration is such that it can escape rapidly, there is relatively little temperature rise and no problem.

If the material is in large masses, so that the heat at the center cannot

escape rapidly as it is liberated, the temperature will increase more and

problems may arise. As the temperature differential between inside-thepile and the ambient increases, the rate of heat conduction increases.
7

Unfortunately, the reaction, and rate of heat production, also go up with

temperature increase. So long as the rate of heat production exceeds the

rate of heat loss, the material increases in temperature; i.e., it "self

heats," This can, and often does, continue until ignition occurs. The

se If - ignit ion temperature is defined [6] as the minimum initial temperature

from which self-heating will lead to ignition.

The Bureau undertook a study of a particular example of this problem

after a disastrous Army warehouse fire in 1950 [12]. This was followed by

more fundamental studies of the phenomenon and of the effects of pile size

and ventilation [13], An adiabatic furnace was developed which simulated

the behavior at the center of a perfectly insulating (infinitely large)

pile. From these studies, suggestions were made regarding maximum size of

unventilated piles in warehouses, as a function of the maximum ambient to

be expected.

The original warehouse fire had been due in part to the fact that the

wood fiberboard had been stacked while still hot from the manufacturingprocess dryers. This is another, related, problem that should be kept in

mind by the military who so often purchase quantities too large to be

supplied from stock.

Ease of ignition is one of the two characteristics of flammability.

The other is being subject to rapid flaming combustion. This rapidity

can lead to high-speed flame spread over appreciable distances. This

aspect will be discussed later in this paper. At this point, we will con- sider mainly ease of ignition and rapid combustion without spread over

large distances. We are all familiar with the easily ignited flammable

liquids such as the petroleum-based fuels, solvents, vehicles, and cleaners.

They volatize at or near room temperatures. The vapors mix with air to

form, within certain ranges of proportions, combustible mixtures which

require but a spark for ignition. Not so familiar are the ignition characteristics of some fabrics, particularly those produced with a fuzzy, or brushed, texture which is subject to surface flash. Several deaths or serious injuries have resulted from ignition of clothing made from such

materials. The Bureau has recently made a study of various test methods

for fabric flammability and now is studying their applicability to non- woven films of plastics, which constitute a small but increasing percentage

of wearing apparel. This work is in connection with the responsibility

assigned to the Secretary of Commerce in the Flammable Fabrics Act [14],

which makes specific reference to two test methods [15, 16].

A final problem on ease-of- ignit ion , of greater interest to the

military engineer than to the general populus, is the effect of new and

exotic materials on the ignition properties of conventional materials.

For example, liquid oxygen greatly increases the ignitability of many

common materials.
- 8 -

3.2 Growth and Spread

If you have ever tried to burn out a tree stump, or even a four-byfour timber, you know that it does not ignite easily nor burn vigorously*

Yet an equal amount of wood in shavings will burn with well-nigh explosive

rapidity. Dust explosions are well documented, occurring in sawmills,

mines, grain storage, and similar cases. Bureau studies have developed

increased understanding of the parameters affecting fire growth in the

range between slow smoldering and flash fires. One very important variable

is the amount of fuel available. Of equal or greater importance is its

distribution. The ratio of surface area to volume and the amount of air

available both enter in. For liquid fuels, this means the broad shallow

pool burns more vigorously than the narrow deep pool. For solid fuels,

the size and packing of the individual pieces are determinants. However,

as spacing becomes large, another effect becomes noticeable. The rate of

burning decreases due to the reduced intensity of thermal feedback from

the flames to the fuel. This is part of the difficulty with burning the

stump or the single four-by-four. No other flame source is feeding energy

to the burning member.

The amount of air available, or the ventilation, has been mentioned

as an important factor in the rate-of-burning. It has been pointed out

how the dispersion of the fuel may regulate the ventilation and, thereby,

the growth of the fire. However, in many building fires, the growth is

controlled by the room ventilation, rather than by the fuel array. The

Fire Research Section s.taff have shown the effect of compartment ventilation on the growth of fires. The rate-of-burning increases linearly with

increase in ventilation up to a transition area where the rate drops off.

Further increase in ventilation is accompanied by a linear increase in

rate, parallel to but offset from the original line of increase. The second

section of the line continues to a level-off, or constant rate. The initial

portion of the line corresponds to the condition where the fuel (wood) is

giving off combustible volatiles which burn at the ventilation opening.

The portion of the line above the transition zone corresponds to the con- dition where ventilation is adequate for the volatiles to burn at the fuel

crib in the compartment. The final constant rate portion corresponds to

the condition where compartment ventilation no longer regulates the fire.

The crib is burning freely, regulating the fire by its own geometry,

essentially as it woxild in the open.

We have seen that the growth of a fire in the room-of-origin is con- trolled by the amount of fuel and by ventilation. The growth, or spread,

to other parts of the building cannot take place unless there is fuel and

oxygen in other parts. However, the mechanism by which it spreads may or may not be dependent on a continuous, oxygen-supplied path of fuel. Gases

hot enough to ignite combustibles have travelled along corridors, stairwells,

and elevator shafts with the result that the fire spreads to distant locations without necessarily involving intervening locations. This may include
9

bypassing combustibles if the hot gases displace the oxygen to the extent

that there is not enough left to support combustion. Also, the hot gases

themselves may be combustible, needing only an air supply for ignition.

A second common mechanism of fire growth, still not involving the

burning of all the combustibles available along the way, is surface flame

spread. Flames spread rapidly over the surfaces of many materials used

to decorate or finish floors, walls, or ceilings; some of these materials

do not burn readily in bulk. The ceiling surfaces are particularly sus- ceptible, due to the buoyancy of flames or hot gases. Also, some surfaces

not originally susceptible to rapid flame spread become so through the

build-up of grease, grime, or multiple coats of paint. The latter becomes

a particularly serious problem in ducts and old structures.

The hazard represented by surface flame spread has been the subject

of much concern by building and fire officials, designers and others. Many

individuals and groups have worked toward the development of a reliable

test method for measuring it. ASTM has adopted a method developed by

Underwriters' Laboratories, E-84 [18], and one developed by NBS , E 162-T

[19], The former employs a 25-ft long specimen; the latter a 6- by 18-in.

specimen, UL has used their method for rating materials since about 1950

and it has been referenced by many building code groups or officials,

and by government construction agencies. The radiant panel method was developed with the aim of providing a small inexpensive apparatus and a simple rapid test procedure suitable for installation and use by manufacturers in their research and development work. It has proved to be of

interest to some building code officials and to the government construction

agencies [20]

,

The two flame spread methods mentioned in the preceding paragraph

are intended primarily for rigid finish materials or finishes permanently

applied to rigid substrates. They also have been used for measurements

of flammability of fabrics and similar materials not ordinarily a part

of the building and, therefore, not always subject to the same building

code or other regulatory provisions. The hazards involved in such materials

are those of a light, well-ventilated, and often easily ignited fuel source,

plus a material used in such a manner that it may permit the spread of a very localized ignition to other combustibles in a room, or to cut off

escape. How many wastebaskets are near draperies? How many dropped cigarettes fall on carpets? Partly because of the different conditions of use and the particular ignition sources to which they are exposed, several

special tests have been developed for fabrics and other thin sheet materials

[15, 16, 17], Our work with some of these has been mentioned in comments

on clothing problems.
10

3.3 Life Hazard

Thus far, we have discussed fire protection primarily in terms of

the buildind and its contents. This was not because life safety was considered to be of secondary importance. It appeared more logical to

describe some of the structure-material considerations before describing

how they applied to life safety.

The protection of life from fire can be accomplished by a great

number of means, but these can be placed under two broad categories:

(1) escape from dangerous proximity, and (2) protection from the effects

of fire until rescue can be effected. These categories are broad and

there is much overlap. The same building elements that would protect

people if trapped in a building may well prevent the entrapment by keeping

the fire from blocking escape routes.

There are a few fire associated hazards to life that are not property

hazards, and vice versa, but for the most part, what is protection for one

is protection for both. Therefore, most of what has been covered thus far

in this paper applies to life safety. I trust the application is obvious

enough that it need not be restated in detail. For example, reexamination

of the fire endurance test criteria [3] in section 2.3 Confinement, will

show that although they are phrased in terms of safety to materials, they

will assure tenable conditions in most adjoining spaces.

Now let us consider life hazards not normally property hazards.

The development of non- life-supporting atmospheres is probably the most

significant. Toxic gases are usually produced as products of combustion.

Phosgene, chlorine, hydrochloric acid, and other exotic gases are produced

by the combustion or thermal decomposition of some organic materials;

large amounts of carbon monoxide are produced by nearly all. Carbon monoxide has been believed to be the most dangerous because of the much greater

quantities produced and the fact that it is odorless and colorless. However,

there is growing belief that a major portion of fire associated fatalities

are cases of smothering; i.e., concentration of non-toxic gas (such as carbon dioxide) builds up to the point that the oxygen content falls below

that required to sustain life. The same effect may result if the fire

depletes the oxygen. For example, after the fire storm at Hamburg in

World War II, large numbers of people were found dead in underground

shelters, with no signs of burns, poisoning, or violence. On the contrary,

they were in relaxed positions. The severe fire had reduced the atmospheric

oxygen content sharply.
11

It appears that relatively little is known about toxic gases and

their effects on human life. The dearth of knowledge approaches totality

when the subject shifts to mixtures of toxic gases. Obviously, this is an area in which direct experimentation would be most difficult. As a result, the approach has been to avoid toxic gases rather than to learn

man’s limits of tolerance. This is just as well f^r, among other good

reasons, the concentrations developed and the duration of exposure

resulting from a building fire would be almost as unpredictable and un- controlled as the fire itself. At present, there is increasing concern

over the inclusion in buildings of materials known or thought likely

to produce toxic gases if involved in a fire.

The other category for means of life protection is escape. This

encompasses requirements for adequate and well-marked exists, fire

doors, enclosed stairwells, fire escapes, internal alarm systems, fire

drills, and directions for alternates such as escape over roof-tops and

through adjoining buildings. A very important subcategory to escape is

the rescue equipment and training of the available fire departments. I am sure we are all greatly indebted to the fire departments for the many

truly heroic rescues they make, only a few of which receive "front page"

recognition.

Several years ago, the Bureau conducted surveys of the traffic

capabilities of corridors, stairways, and exits [21] which served as a guide in the building exits provisions in codes. Recently, we have

completed a study of the effectiveness of dwelling doors, and of modifications to them, as barriers to fire and smoke [22], We are engaged in

continuing studies related to the development of smoke and toxic gases

from materials. A paper describing a method for measuring smoke will be

presented next month at the Annual Meeting of the American Society for

Testing and Materials. As many of you know, a smoke -b locked corridor

represents just as much a barrier, psychologically, as a wall of flames

or of brick, to most people. This was demonstrated tragically in some recent fires and is receiving greatly increased attention by building

officials. It is to be hoped that the effects of discipline make this

a less significant hazard to military personnel.

3.4 Property Hazards

A fire in a building represents a great hazard to the building and

its contents. The direct effects of heat and flame include ignition and

combustion, structural damage and collapse, smoke damage, etc. Broadly

speaking, "smoke damage" can range from a lingering smell, through discoloration, to harmful chemical changes and rapid corrosion. The same hydrochloric acid that could kill those trapped in a building could ruin

a storage of precision military equipment. The water used to fight a fire can be just as damaging to the contents as the fire. Of course,
12

with the water there is hope of reducing extent of damage to something

less than total. The merit of adequately designed and maintained

sprinkler systems is the ability to attack the fire quickly and to

minimize the extent of the fire, and of water damage.

However, the hazard due to a fire is not confined to the building

of origin. Mrs. O'Leary's cow kicked over the lantern on a very windy

day in Chicago. Direct impingement of flames from a burning building

to an unignited one, flying brands, and thermal radiation all represent

means of ignition to nearby structures or materials. The Bureau has

studied the susceptibility of materials to ignition from all these

sources, often at the request of the military agencies, although we do not now have any on-going work on any of them. The Japanese, Canadians, and

British are all working, or have done work recently, on the spread of

fires between buildings.

3.5 Non-Building Fires

Although this paper is directed toward building fires, it seems appropriate to make brief mention of non-building fires. Many of these

are of importance to the military.

Shipboard fires are most often in the public eye in terms of commer- cial or passenger vessels. This falls under the interests of the Coast

Guard (Treasury Department) and the Maritime Administration (Commerce

Department). However, the same considerations apply to military transport

vessels. Some years ago, during the design of the SS United States, the

Bureau's Fire Research Section conducted a full-scale stateroom burnout.

More recently, we provided a member of a committee to investigate the

need for rules (by Coast Guard) on the fire safety procedures for empty

tankers. At present, we are providing a Technical Advisor to the U. S» Delegation to the Inter-governmental Maritime Cooperative Organization.

Aircraft fires are also a serious public hazard. The Federal

Aviation Agency has had a fire program for several years. The Bureau has

helped FAA , both with particular studies and with the development of FAA's

in-house facilities and competence.

Fires are a problem to other transport systems. Buses, trucks,

trains, and private automobiles are all susceptible to fires, particularly

as an aftermath of accidents. The Interstate Commerce Commission has

regulations on the handling of hazardous cargoes.
13

Natural resource fires represent a great loss in themselves and a hazard to buildings, transportation systems, and other materials. The

Bureau of Mines is very active in the area of fire safety in mines and

oil wells. The Forest Service is concerned with forest and prairie

fires, and maintains several excellent laboratories. The Department of

Agriculture publishes information on the specialized problems of farms

and the application of fire technology to those problems.

4. Non-Government Activity

The extent of non-government fire research and fire protection

activity is difficult to assess. Industry carries on a very large program

of research and development; its description is beyond the scope of this

paper. However, it is a very important and significant source of technical progress. A few examples must be mentioned. These include the work

of the Underwriters' Laboratories [10] and Factory Mutual Engineering, of

Ohio State University and Southwest Research Institute; the publications

of the National Fire Protection Association [12, 17, 23, 24] and the

American Insurance Association (formerly National Board of Fire Underwriters)

[7, 11]; and the model codes developed and promulgated by the Building

Officials Conference of America [25], the International Conference of

Building Officials [26], the Southern Building Code Congress [27], and

AIA [28]. The Portland Cement Association has excellent facilities in

Skokie, Illinois. Several individual companies have installed furnaces,

tunnels, radiant panels, smoke measurement equipment and/or other fire

test apparatus. These are used for the development of proprietary products.

Several trade associations that do not have their own facilities have been

very active sponsors of tests or studies in commercial or university

laboratories. Because industry is interested mainly (and quite naturally)

in publicizing only those final developments it chooses to market, the

extent of their work is not obvious. The large number of new products that come on the market indicate that industry’s efforts are quite large. The

development of fire-fighting equipment is largely an industry activity,

responsive to the needs of fire departments. In addition to new products,

industry has produced many of the test methods and of the improvements

thereto.

5 . Summary

This paper has attempted to describe technical considerations involved in the field of fire protection and, thereby, point out the breadth

and complexity of this field. It has pointed out areas in which the

National Bureau of Standards is working or has worked. To a lesser degree,

it has made mention of the work of other Government agencies, and of non- government organizations. This is not intended to slight in any way the

work of others than NBS ; it merely reflects the author's greater familiarity

with the work of NBS.
14

The field of fire protection has been broken into areas such as material (or occupancy), structure, and life safety. It has been viewed

under the subjects of ignition, growth and spread, confinement, detection,

extinguishment, and smoke and toxic products. Yet the complexity of the

problem, and the ingenuity of some of the technical advances, are such

that rarely can it be properly said that any one item falls clearly under

only one area and subject.

6. References

[1] A Short History of the Structural Fire Protection of Buildings,

S. B. Hamilton, National Building Studies, Special Report No. 27,

Department of Scientific and Industrial Research, HMSO, London,

1958.

[2] Early History of Fire Endurance Testing in the United States, H. Shoub

,

Special Technical Publication No. 301, American Society for Testing

Materials, October 1961.

[3] Standard Method for Fire Tests of Building Construction and Materials,

ASTM Designation E 119-65, American Society for Testing and

Materials 1965 Book of Standards, Part 14, November 1965.

[4] Standard Methods of Fire Tests of Building Construction and Materials,

NFPA No 251- 1963 , National Fire Protection Association, 1965-1966

National Fire Codes, Vol. 4.

[5] Standard for Fire Tests of Building Construction and Materials,

UL 263, Underwriters Laboratories, Inc.

[6] Definitions of Terms Relating to Fire Tests of Building Construction

and Materials, ASTM Designation E 176-64T, American Society for

Testing and Materials 1965 Book of Standards, Part 14, November

1965 (Accepted as a standard in 1966, but not yet printed as such

Ln Book of Standards).

[7] Fire Resistance Ratings of Less than One Hour, National Board of Fire

Underwriters (now Engineering and Safety Department of American

Insurance Association), New York, May 1964.

[8] Fire Endurance of Open-Web Steel-Joist Floors with Concrete Slabs

and Gypsum Ceilings, J. V. Ryan, Building Materials and Structures

Report 141, National Bureau of Standards, August 1954.

[9]

Fire-Resistance Classifications of Building Construction, BMS 92,

National Bureau of Standards, Octover 1942.
15

[10] Building Materials List, Underwriters' Laboratories, Inc., Chicago,

January 1965 (published annually, with supplements bimonthly).

[11] Fire Resistance Ratings, National Board of Fire Underwriters,

New York, December 1964 (since this edition was issued, NBFU has

become the Engineering and Safety Department of the American

Insurance Association).

[12] New Light on Se If - Ignition , N. D. Mitchell, Quarterly, National Fire

Protection Association, Boston, October 1951.

[13] Pile-Size vs. Self-Ignition Temperatures of Materials from KineticReaction Data, D. Gross and A. F. Robertson, Research Paper 2909,

J. Res. NBS , November 1958.

[14] Flammable Fabrics Act, Public Law 88, 83rd Congress, 1st Session;

15 USCA 119.1; 67 Stat. Ill, Approved June 30, 1954.

[15] Flammability of Clothing Textiles, Commercial Standard 191-53,

January 30, 1953.

[16] General Purpose Vinyl Plastic Film, Commercial Standard 192-53,

May 22, 1953.

[17] Standard Methods of Fire Tests for Flame-Resistant Textiles and

Films, NFPA No. 701, National Fire Protection Association,

National Fire Codes, Vol. 3, 1965-1966.

[18] Standard Method of Test for Surface Burning Characteristics of

Building Materials, ASTM Designation E 84-61, American Society

for Testing and Materials 1965 Book of Standards, Part 14,

November 1965.

[19] Tentative Method of Test for Surface Flammability of Materials

Using a Radiant Heat Energy Source, ASTM Designation E 162-62T,

American Society for Testing and Materials 1965 Book of Standards,

Part 14, November 1965.

[20] Flame-Spread Properties of Materials, Interim Federal Standard

No. 00136b (COM-NBS ) , December 26, 1962.

[21] Design and Construction of Building Exits, Miscellaneous Publication

M151, National Bureau of Standards, October 10, 1935.

[22] Doors as Barriers to Fire and Smoke, H. Shoub and D. Gross, Building

Science Series 3, National Bureau of Standards, March 25, 1966.
- 16

[23] National Fire Codes, 1965-1966, in 10 volumes, National Fire

Protection Association, Boston.

[24] Fire Protection Handbook, 12th Edition, National Fire Protection

Association, Boston, 1962, 2nd printing 1965.

[25] Basic and Abridged Building Codes, Building Officials Conference

of America, Chicago.

[26] Uniform Building Code, International Conference of Building

Officials, Los Angeles.

[27] Southern Standard Building Code, Southern Building Code Congress,

Birmingham.

[28] National Building Code, National Board of Fire Underwriters (now

Engineering and Safety Department of American Insurance Association)

New York.