NEAFC 31st Annual Conference.pdf - New England Association of ...

NEW ENGLAND ASSOCIATION OF FIRE CHIEFS
cific gravity of natural gas from the Gulf :Coast area is approximately 6 tenths, which
is very.nearly that of the manufactured gas to which most of you are accustomed. Contrary
to some public conception, natural gas is lighter ~than air and consequently will
rise and dissipate itself if adequate ventilation is provided.. This is in contrast to lique,
fled petroleum gases--that is, propane or :butane or a mixture of the two--which are
heavier than air (specific gravity 1.~), and if leaks occur, will be found in the buildings
at or near floor level. I have also calledl your attention to the fact that natural gas has
extremely narrow limits of inflammabili.ty. In fact, the limits for natural gas are from
~-1~ per cent. This means that gas-air mixtures containing from ~ to l Y per cent of
natural gas in air will Burn, but that if the natural gas is less than ~ per cent of the
mixtureor mo.re than 1~ per cent of .the mixture, it will neither burn nor explode.
These figures compare with flammability limts of 4 to 30 per cent for ordinary manufactured
gas with which you are familiar. The same combustible gas indicators which
you have used in testing from manufactured gas may .be used to indicate the presence of
natural gas.
Natural gas is also odoriaed for ready detec.tiod in case of leakage. Natural gas,
as it .comes from the well, is almost odorless but Public Utilities Regulations in Connecticut,
Massachusetts and New’Hampshire require odorization. Northeastern Gas has
installedl odoriaing equipment at the New York Massachusetts State line, so that all
gas transmitted in New England is odorized to such an extent that a mixture of l~
of 1 per cent of the natural gas in air is readily detectable by the average nose. This
odoran.t is designed to have an odor similar to the manufactured gas with which you
are familiar so that if a gas leak should occur, people will immediately associate the odor
with gas. In fact, natural gas is very similar to manufactured gas except, of course,
that it is safer, cleaner, and cheaper.
In entering gaseous atmospheres, it is, of course, unnecessary to use a poison gas
mask. However, it is. possible to have an atmosphere so high in n.atural gas concentration
that insufficient air will be provided for breathing. In this case, the air type of
gas mask is necessary. Not only is natural gas safer as regards toxicity and asphyxiation,
but statistics prove tha.t it creates less fire haaard than comparable fuels. The Boston
Office of the Nati.onal Fire Protection Association has recently issued statistics
~howing-that for the period from 1941 to 194Y electric wiring and appliances caused
f~,700 fires with: a loss of $32,000,000. ’Coals and hot ashes caused 13,200 fires with a
loss of $3,600,000, whereas gas and gas appliances, both natural and manufactured,
caused only 4,300 firedwith a loss of $2,4~0,000.
An interesting sidelight on comparative hazards is also providec~ by the fact that
during the period from 1923 to 1949, there were 32 coal-dust explosions reported, causing
28 deaths and 31 serious injuries, and I might also call your attention to the fact
that due to the very n.ature of gas service and! ~he fact that mains and pipelines are installed
underground, it is less subject to interruptions and: the haaards attendant to ino
terruptions, than any other type of fuel from the standpoint of storms., floods, tornadoes,
strikes, etc. Let me caution you, however, that all companies having natural gas pipel
line service do not necessarily plan .to use 100 per cent natural gas. Norwalk, Connecticut,
for instance, is distributing a mixture of manufactured and natural Which has lethal
perercentages of ’CO. ,Lynn is mixing, and Boston plans to mix. Also most distribution
companies are planning the use of propane standby facilities, which will be used in some
cases for peak load control and generally for emergency stand’by in case of maintenance
~interruptioni on the pipelin.e. Each of you should contact your local g~s company to
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