CGWIDENTIAr
AME 6WETOTRE ON PU.IN AND FILTER TIPPED CIGAFFTTPR
a nun
The following statement provides information on
ber of questions
that have been asked about plain and filter tipped
cigarettes.
1. Cigarette smoke consists of three groups of
substances:-
(a) Uncondensable or permanent gases.
W Condensable vapours. (These are substances which
can
be condensed by the application of moderately low
temperatures).
(c) Particulate mai ,e"rial. (These are minute
droplets of a
highly complex nature suspended in the mixture of
vapours
and gases).
2. A medium-size plain cigarette contains about
one gram of tobacco.
The total puff volume of the average smoker is
slightly over 3/10ths of a
litre per cigarette. The main gases in the smoke
and the quantities in which
they ore present are approximitely 260 ml.
nitrogen, 45 mi. oxygen, 28 mi.
carbon dioxide and 9 mi. carbon monoxide.
3. The ucight of particulate material (at room
temperature, including
water) in the smoke from a cigarette is about 30
mg. 1~ further 10 mg. of
vapours are obtriined by cooling the smoke to
about - 700C. It is not known
whether the relative weights of these materials
have any relation to their
possible importance for health.
4. Materials having a beneficial effect on flavour
as well as
materials which have been suspected by one
scientist or another as possibly
being undesirable are to be found in each of the
three groups of substances
in cigarette smoke.
5. The filters on U.K. filter tipped cigarettes
remove more of the
particulate material from the smoke than would the
corresponding length of
tobacco. In almost all cases, therefore, filter
cigarettes yield less
particulate m.-iterial than plain cigarettes of
the same size. On the other
hand, filter tipped cigarettes give at least as
much vapours and gases as plain
cigarettes of the some size. The yield of
particulate matcriz-1 is affected
not only by filter efficiency but also by the
tobacco blend and density, paper
(J-4
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BATCo document for Province of BritiSh Columbia 29
October 1999


porosity and other factors.
6. The popular brands of both plain and filter
tipped cigarettes
give the smoker widely varying amounts of
particulate material. It would,
of course, be possible to produce a filter that
removed all the particulate
material and some of the v0pours and gases, but
t;ic result would not satisfy
the smoking public.
T. It was at one time considered that substances
could not be
selectively filtered out of cigarette smoke.
However. selective filtration
is now possible for several classes of compounds -
for example, phenols and
oldehydes. Until more is known about possibly
harmful or undesirable constituents
of cigarette smoke there is no clear bcsis for
judging the value of chemically
selective filters. Nevertheless, if remcval of any
classes of compounds is
shown to be desirable, their selective removal by
filtration is a possibility.
8. Biologic.-il experiments hnve brought certain
substances in cigarette
smoke under suspicion of possibly being h=rmful.
However, no one has yet been
ible to identify any spccifir substance in
cignrette smoke. whether filterable
or not, as definitely being hn-rmful to the smoker
in the quantities in which
it is present. For example, 3:4-benzpyrene was an
early suspect but in 195T
the Medical Resecrch Council stated thit "there is
no certainty that it is
hnrmful in such low concentration". i,urther
experiments are in progress on
a large scale, notably at the Tobz!cco Research
Council L:,boratories nt
Harrogate, to ascertain whether any ond, if so,
what changes in the constituents
of tobacco smoke Ore desirable and possible.
25 th April 1963.
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BATCo document for Province of BritiSh Columbia 29
October 1999