NATIONAL BUREAU OF STANDARDS REPORT

5^61

A GLOSSARY OF TERMS APPLICABLE IN THE SCIENCE

OF FIRE PROTECTION

C, S, McCamy

<^NBp>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
THE NATIONAL BUREAU OF STANDARDS

Functions and Activities

The functions of the National Bureau of Standards are set forth in the Act of Congress, March

3, 1901, as amended h) Congress in Public Law 619, 1950. These include the development and

maintenance of the national standards of measurement and the provision of means and methods

for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials,

devices, and structures; advisory services to Government Agencies on scientific and technical

problems; invention and development of devices to serve special needs of the Government; and the

development of standard practices, codes, and specifications. The work includes basic and applied

research, development, engineering, instrumentation, testing, evaluation, calibration services, and

various consultation and information services. A major portion of the Bureau’s work is performed

for other Government Agencies, particularly the Department of Defense and the Atomic Energy

Commission. The scope of activities is suggested by the listing of divisions and sections on the

inside of the hack cover.

Reports and Publications

The results of the Bureau’s work take the form of either actual equipment and devices or published papers and reports. Reports are issued to the sponsoring agency of a particular project

or program. Published papers appear either in the Bureau’s own series of publications or in the

journals of professional and .scientific societies. The Bureau itself publishes three monthly periodicals, available from the Government Printing Office: The Journal of Research, which presents

complete papers reporting techni*‘al investigations; the Technical News Bulletin, which presents

summary and preliminary reports on work in j>rogress; and Basic Ratlio Propagation Predictions,

which provides data for determining the best frequencies to use for radio communications throughout

the world. There are also five series of nonperiodical publications: The Applied Mathematics

Series, Circulars, Handbooks, Building Materials and Structures Reports, and Miscellaneous

Publications.

Information on the Bureau’s publications can be found in N BS Circular 460, Publications of

the National Bureau of Standards (SI. 25) and its Supplement ($0.75), available from the Superintendent of Documents, Go\crnmcnt Printing Office, Washington 25, 1). C.

Inquiries regar«ling the Bureau’s re|)orts should he addressed to the Office of Technical Information, National Bureau of Standards. Washington 25, D. C.
NAT30NAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

1002-30-i+873 September 17? 1957 5^61

k GLOSSARY OF TERMS APPLICABLE IN THE SCIENCE

OF FIRE PROTECTION

by

Co So McCamy

IMI’OHIANT NOnCt

NATIONAL BUREAU OF STAN ^mtss accuunting dociiiiK‘iit;> intended for use within the Go Approved for Public release bv the puidislu,d it is Subjected

to additional evaluation and rev

i xt • i i ^n pmduction, oi open-iileiature

listing of tliis Report, either in Uirector 01 the National Institute of n obtained in wiiting troin the Office of tlie Director, Natio Standards and Technology (NIST) icit permission is not needed,

however, by the Government ag On Octobcr 9 ^015 epaied if thai agency wishes

to reproduce addition.d copies ' • <NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
..

^

, M,,

S?f

T«;#«5 3« , at: tS:"!II ; .Jr*

7-I&5TO

'vif

' "i! vi.';’'':'^

i’l"! ;a. ''

i > - ^ i,^-3m-i.i .- u-rmij-Mm.-^'- • '' ^ ''i*. ^ % 'Vii! . ., ., 'TSii^nsa .

.;. .. .it- S',.....: i.'.-c^./"' V'

ItEITPSfISf

iv «

:

' ;li. V;.' £u\K.

!''• %U -'’^''rvl;'.'

•' ,.. kHl

' ' ''

''

'

' 'll

'

' '• '^‘i’ ' V,'.'

‘ ' ' v-,

sr.;\

J»i'>

* ^ -. .- ' I'l Li _ '

'., •'

:' ''''4'

-4 :.'a«;Ss &i

f . '>F

, :., :j- /

'.,

, 4}>1> iV>il :'j.v^»v«*'a7*v4 jif 4«.M»'*'i1«rYit' vilti4«.H/

•" »i ie»'lt»|'»-.» '(.H cl »*»l'H»:«4.t -ilubH .)«'>,

1+ ",;,,m‘.](W!'', . vf,, ^i^l;^sCT),^^ i<f*t||i»4' ti!r,jito(*t’;!f I'w *i! W

. . 4 >*wt.t»-ii4M4'4<j 'I ,D CImJ'S «'ir'4«n‘rfM,7!5'

^!.'i4t; 4/ '1 ’V^^.0'?t'^^((^V., vj. yi}<;.iftn'.'4) ' ^ l‘«i(

....

' .'»» >**«* »f<l ’’'^' '’ *“'

''1V3

lO'SaiMOS J,

A'l/'.

' X,

I I. \i! , "<f.%uU'f2l''i W. Mi#K

,.;4'<''V..i,i;;iMi

#““'*.,

;( V , 4s?*

Ki. ,

'
A GLOSSARY OF TERMS APPLICABLE

IN THE SCIENCE OF FIRE PROTECTION

ABSTRACT

A glossary is presented of terms used in

the application of the science of fire protections,

PREFACE

Since prehistoric times man has sought to protect

himself from the ravages of uncontrolled firee In spite

of the great progress that has heen made toward greater

security in this respect and the amount of attention this

subject has received 5 there remains a general lack of

uniformity and precision in the terminology of fire

protection scienceo It is the object here, to formulate

definitions of some of the terms applicable in this science*

In dealing with definitions it must be recognized that

there are different kinds of definitions for different

purposes* Descriotive definitions describe the present or

past use of words* Such definitions are statements of

fact, the truth of which can, in principle at least, be

ascertained by comparing the stated definitions with

observed usage* PmsGrintive definitions , on the other hand

prescribe the meanings of words* These definitions are

not statements of fact, but are of the nature of invi=

tations, commands, or conventions to employ words in speci=

fied ways and, therefore, can neither be true nor false*

One of the fundamental tasks of science is the

development of clear and precise concepts and terminology*

A major part of this task is the formulation and acceptance

of prescriptive definitions* Although it maj;" seem that a

definition is "all a matter of words", it is an inescapable

fact that the precise boundaries of the quantities to be

treated in a given science are set down in the definitions

of the nam.es of those quantities* In the final analysis,

the meaning of every h3?'pothesis , theory, and statement

of fact depends upon the definitions of the terms in which

it is expressed*
= 2 =

ft.lthough prescriptive definitions may be neither true

nor false, they may be good or bad according to how useful

they can be in simplifying and systematizing statements of

fact and theoretical propositions o Definitions of this

kind must be judged, first of all, on the basis of usefulness o To be useful, the various definitions employed in

a given area of science must, of course, be consistent

with one anothero There are obvious advantages to be

gained by choosing definitions consistent with those already

accepted in allied fields of sciences In fact, it may

be well worth while to seek a formal correspondence between

the system of quantities and terms to be used and some

existing system* If a complete formal correspondence

exists between the mathematical relationships among quantitjes

in the two systems, the whole mathematical treatment of the

prior system may be applied to the subsequent system* The

analogy between the classical dynamics of a damped harmonic

oscillator and the electrical theory of a series R-L-C

circuit is one of the better known examples of this concept*

The correspondence in this case has for many years been

usefully employed in solving problems* This principle of

analogy is the basic principle of operation of a large

class of computing machines * Although, in principle, prescriptive definitions may

be established quite arbitrarily, capricious disregard for

existing general usage could bring about more confusion

than clarification* In most eases, the best interests of

science are served by choosing terms in general use and

giving them useful technical meanings differing from the

usual meanings mainly in precision and objectivity* As a

general rule, this is the intended approach here*

General usage continually evolves in various ways*

So it is with technical usage, as concepts develop and

the qualities of nature become better knom, the meanings of

terms must be refined* Thus, it is not with the thought

of ending the matter of definitions that the following

terms have been defined, but rather with the hope of

establishing a reasonable point of departure*
=3-

A GLOSSARY OF TERMS APPLICABLE

IN THE SCIENCE OF FIRE PROTECTION

arc 5 no

a sustained luminous el.ectrical discharge formed when

a break is made in an electric circuit which is

carrying currento

burn, Vo

intransitives to undergo a persisting destructive

change in essential properties as a result of high

temperature or combustion

transitive; to cause something to burn in the sense

defined above

burnable, ad jo

capable of being burned under the stated or implied

conditions

‘ burning, no

an instance of something being burned

burnt, ad jo

having been burned

chain breaking , 'O

the process of terminating the sequence of reactions

involved in a chain reaction, usually by removing or

modifying the chain carriers, the agents produced

during the reaction and necessary for completion of

the reaction

chain reaction ^ a reaction in which one or more of the agents necessary

to the reaction is prod?aeed by the reaction so as to

permit like reactions

combustible, adj»

capable of undergoing combUuStion under the stated or

implied conditions

combustion, n®

a chemical process, usually of a complex nature, w'hich

occurs mainly in the gas phase and which liberates

energy, at a high rate in part by heat or lights an

oxidation process is usually invol.ved
-4-

explosive, no

an explosive is a material which is capable of suddenly

liberating the energy which it contains, causing a

sudden increase in pressure or movement of natter

in the surrounding mediumo

fire, ne

burning regarded generally as a destructive agency

fire endurance, n.

the time period during which a structure resists fire

according to a specified criterion and under specified

conditions

fireproof, adj®

capable of withstanding the effects of fire

Note; Since no known materials fulfill this defined

and generally understood meaning, under all

conditions , the use of this term is to be

discouraged®

fire resistance, n®

the extent to which a material or structure resists

the effects of fire

fire resistive, adj.

fire resistant, the preferable term

fire retardant, adj.

tending to retard the effects of fire to a lower

degree than materials classified as fire resistant.

flame, n®

a body of gas or of matter in gaseous suspension undergoing combustion and usually emitting light as a

consequence

flameproof, adj®

not being readily ignited by a flame nor able to

propagate flame under the stated or implied conditions

flame propagation , yn

the movement of the combustion zone with respect to

the unburnt gaseous fuel
- 5-

Note Is The combustion zone may be fixed with respect

to other objects such as a burner or

flame-holder

o

Note 2; The movement of the boundary of the flame

zone with respect to the solid or liquid

fuel is called ’’flame spreado"

flame spread ^ bn - the movement of the boundary of the flame zone with

respect to the solid or liquid fuel

flammable, adj®

capable of supporting vigorous combustion and of being

easily ignited under normal conditions

Note: Because of the possibility of confusion of the

meanings of the prefix "in-”, the term

"inflammable" is not to be usedo

fuel, n®

1) matter which undergoes exothermic reaction in a

fire, thereby contributing a destructive effect

2) matter consumed by combustion to produce heat of

power

3) when a rocket propellant is composed of two separate

materials (a bipropellant system) , the two materials

may be called the "fuel" and the "oxidante"

ignite, v,

to initiate combustion

ignition, n,

the initiation of combustion

noncombustible, adj«

not combustible

nonflammable, adj»

not flammable

resistance, n«, the opposition offered by a substance or body to

being affected by or allowing the passage of a

specific effective agency
- 6-

retardj Vo, transitive

to delay or impede the action of a specific effective

agency

spark, no

1) electrical spark: a sudden electrical discharge

of extremely short duration between two objects

separated by air or some similar medium, resulting from

a high potential gradient

2) fire spark: a small, isolated, glowing particle

3) mechanical spark: a small, isolated, glowing

particle produced upon impact between hard objects

o
U. S. DKPAJn'MKM OK COMMKHCK

Sinclair \\ ccks. Sc< r<7nr%

NATIONAl, Ul’HhAU OK ST'M)A|{I)S

A. A si in. Director

l ui: N aiioj\al buri:ai! of standards

The Kcope of activitie.s of the fS.itional Ifureau of Stamlardis at its headquarters in Washington,

D. C., and its major field lahoratories in Boulder, (Colorado, is suggested in the following listing of

the divisions and sections engaged in technical work. In general, each section carries out spe- cialized research, development, and engineering in the field indicated hy its title. A brief

description of the activities, and of the resultant reports and publications, appears on the

inside front cover of thi.'^ report.

WASHINGTON, 13. G.

Electricity and Electronics. Resistance and Reactance. Electron Tubes. Electrical Instruments.

jMagnetic Measurements. Dielectrics. Engineering Electronics. Electronic Instrumentation.

Electrochemistry.

Optics anti Metrology. I’liuiorn* try and Kolorimetry . Optical Instruments. Photographic

Technology. Ltjngth. Engineering Metrology.

Heat and Power. Temperature Physics Thermodynamics, liryogenic Physics. Rheology

and Lubrication, Engine Fuels.

Atomic aiitl Radiation Physics. .Spectroscopy- Hadiomelry. Mass .Spectrometry. Solid State Physics. Electron Physics. Atomic Physics. Nuclear Physics. Radioactivity. X-rays. Betatron. Nucleonic Instrumentation. Bailiological Equipment. AE(i Hadiation Instruments,

Chemistry. Organic Coatings. Surface (diemistry. Orgiuiic Chentistry. Analytical Chemistry,

Inorganic Chemistry. Fdectrodeposition. (ias (diemistry. Physical Chemistry, Thermochemistry. Spectrochemistry. Pure .Substances. Mechanics. Sound. Mechanical Instruments. Elnid Mechanics. Engineering Mechanics.

Mass and Scale, (iapaeity. Density, and Fluid Meiers. Condiustion (Controls.

Organic and Fibrous Materials. Rnhlier. Fextiles. Paper. I.eather. Testing atui Specifications. Polymer Structure. Organic Plastics. Dental Reseandi.

Metallurgy. Thermal Metallurgy Chemical Meiallnrgv M«‘chanical Metallurgy. Corrosion.

Metal Physics.

Mineral Proibicis. Engineering ( icranuc.^ Cla -r . R*d i iu t«n io. Enameled Metals. Concreting

Materials, Constitution ami Microstructurc

Building Techuolug’,- , 'Structural EugUMciing f uc Pmlcct iim flcatiiie and Air Dondttiouiijg. Floor, HooK »nd WaU (aivcring.'- t.ndcs .ind .'^pc« ilicaliuiis Applied Malhematiis. .Numerical Analvsif- Compulation. Siatnticai Engineering Mathematical Phvsics.

Data Processing Systems SEA(i Engineering Croup, tiompvmenis and '! echniques. Digital

(iircuitry. Digital System.'^. Analogue .Systems. Apjiliealion Engineering.

• Office of Basic Instrumentation • Office ol Weights and Measures

BOULDER, COLORADO

Cryogenic Eugiift^i-ring. (iryogenic Equipment, (iryogenic Processes, Properties of Materials,

(ias Liijuefaclioa.

Radio Projiagaliou Physics. Ujiper Atmosphere Research. Ionospheric Researcli. Regular

Propagation Services. Sun-Earth Relationships.

Radio Propagation Engineering. Data. Rediution Instrumenlalion. Modulation Systems.

Navigation Systeois. Radio Noise, 'i'roposplierii' Measurements. 'I ropospheric Analysis. Railio

Systems Application Engineering.

Kariio Standards.

Standards, Radio

Center. Microwave

Radio Fretpieneies. MiiTovvuve Ert*qnencies. High Frequency F.looiricul Broadcast Scrvici'. High F’requeiiey impedance Standards. (.alihralivm

Physics. Microwavi' Circuit Standards.
NBS