6
LO C. L arorte, E-c, 25th April, 199A
SOMetying to .'.'Oilr 'u-nowledcle b., for t,,r 1-d bellzpyrene if you
like to send m ci-nrett4' @ade fro-a th- e. tv-t@,d tobacco.
I will Leep you pcsted frcm ti-e to time with a general
arpreciation of fl-s-, wnrk we hf@ve been @oi@g -nd are intending to de,
Pni I should be 7ost -rntcful if you .,-uld do tbe sarie for me.
'Ir. Ilood was here -Prt,3rdv.,- -3nd pnrsed cn mesraess from you
nrid yotur colle7gues. I should, in f-,zrn, to be remembered to them
and send you qIl my best wishes.
4ith kindest regards,
Yourn- sinzer,@lys
C.c. L. '.F.Ilctson. Esq.
Si@ Charles Ellis,
Dr.D.G.Felton
C=)
-Ch.
BATCo document for Province of BritiSh Columbia 21 April 1999

5
L. C. Lanorte. Esn. 25th ADril, 1958
The effects of variois casing and other materials upon the
Production rf smoke condensables also comes into this project, the aim
@eLng to rcduce these materials In mainstream smoke if possible.
We nre very intert.,rt;--d to lf7-,rn !, r yo r exreriments on extracting
tobacco with hexane and should this prove to be worth pursuing, we would
be grateful if you could make available to us some thoussnde of the
aiF,arettes together with untreated controls, so that we might investigate
th-3 benzpyrens and tar contents of the smoke.
PROJEGT.J
lt'lourh this is h2-died by the -7,oke Grcup, it does not deal
wi-h the anil-sis of sroke in any way. It is en inve:Aigntion of methods
4
fo- the control of infentations of one cort or the other.
Pr,-)Ject 9 - !-o@e F-;aluation of PM
L-:tluding the org-ninntion end Inforpreting, of smoking tests by
p3 iels, PCL sa-ple cig-r-tt, z tire being evaluated for t-)r Production and
th,@ ccrr-@,lotion of t' is with ch.- '!ngra in the formulation of the PCL. The
ain is to try to ensure that PCL contributes lcvs tar (at any rate, not
.-O-e) to the s--oke than dces an equivalent weight of tobacco. Simultaneously#
th-3 formation of 3-4-benzpyrene during the burning of @,CL is being
investignted. 14hen the nnolysis of the volatile friction of smoke is
establisheci, the technique of G-9 Chronatogrophy will be arplied to control
anJ PM-contsininr, cirrette3 of the I'Vicercyll blend to investigate the
mixture of any 'off-taste" which may be found.
!'e would very much like to discover the bpsic ways in which tar
is formed In smoke production ond as a start on this uo are measuring the
quantities of t*r Traduced from the different pnrts Pf the leaf and from
the different constituents of casing. To linzord a guess, the picture is
probably complicated by these effects rot being additive.
I taking i h- ,said enough to Five you a general picture of what
we nre doing# and unn s t 7 nd I tis not"the Intentirn thrt voluminous
reports shall flow back snd forth between us but rather that the general
outline shclild be kept Jim to date. Wht@re either of li@ finds the other's
work to be of Internet, we 3hould esk for details of that Particular
subject. 7heref.irn, I hope that you will risk for dctd1s from are of any
part of the above 3bout whoch you want to know n:ore.
I shouldt -s nlre,3dv mentioned, like to know mcre about your
tcbacco extraction when you hrve more to tell, -n-1 we -night be able to add
U1
BATCo document for Province of BritiSh Columbia 21 April 1999

4
L. C. LnDortp. Fsc. 25th April, 1958
ured in describing taste nni fle7our of s--nke. e have collated a
number of the-qe from various rr-,rts of the world find hove endeavoured to
place them on a common bnsis @hich can be agreed and then used throughout
the Oraanisation. Until this can be done, we feel little progress can
be made.
Concurrently with that# we intend to or ly the technique of
.p
Gr-s-Chromttogrnphy to the nn-lysis of the vol-tile friction of tobacco
s-oke in order to see whether 1.@e can correlate certain tastes and flavours
with particular chemical entities in the smoke. Ie can then endeavour to
trnce these tn nnrticulnr types or leaf in a blend and see what can be done
to r@odify them send so chnnes the tosto nnd flnvour. Ye have just began
to receive olir equipment ind hope to lenrn a lot from It.
PROJ7CT 3 - How 5'mo@,o Is Fcr7e,J. Heit frrl !,at,?rind Balance of a Cigarette.
At nre!ient this h,!s been re-oved frcri -ur smoke prograrrie but it
is probsble tl-r:t q c,)rrqid,@r!?ble a-nint of work will be carried out through
T.11.S.'-. qt q London university.
We -2re intriguc!d by the f-ct ti-int the CO-/-C-) ratio cf tobacco
sncke vnries --dth th- r0rflow throu,-h !i ci,7nrette 4f)ndj, -moreover, that there
anvocrs to '-e ore CO, present than cnn be eccounted fx by the oxygen
!Itilired In combustion. !Jhere eocs the e:.trn C02 come from? via also
want to unravel how tlie b-@sic combustion proce--ses occur -ind to discover
how much heart is nnde nvnilable f(-r dirtillYntion processes. For example,
what centrols the maxinum te.-per,)ture r-ached in the coal and is this
maximum vnlue significant -.!h,-t effects do the dimensions of a cigarette
hove rn the combustion
All we h-.-!ve done in the nnct is to invejtignte the messarement
of te-parnt-ire -nd to explore some of the effects- which can be potential
sources of error.
PROJ7-CT 4 - Fmoking and Health
This project deals with more specific investigation of smoke for
particular compounds which m1p
.,ht be indicted. In the first instance, we
have set up, es a routine procedure, the as-ay of s-toke for 3:4-benzpyrene
by fluorescence micraspoctrophotometry. leaving proved the consistency of
the method by several assays, it wns applied to smoke from various portions
of the cigarette, when a considerable difference was found between the
sioke from the first ind second halves of the ciporette. It will also
be applied to Inve-stignte Lany effects due to cozings and other materials.
Je aim to I-eep this t@@ol uell-honed in rnedines- for a possible need.
C=>
CF-%
BATCo document for Province of British Columbia 21 April 1999

3
L. C, Laporte, Esq. 25th Aprilt 1958
From the value of Ki we find fcr a particular filter, we define
a Retention Coefficient, O, such that
Ct KA
which we think may be a char3oteristic design constant for a particular
filter and one which will enable tics to cc--mire the efficacy of different
types .)f filter, which possess varying pressure drops etc.
!t this point we ahou-ld interpoInte thit we concern ourselves
with Absolute Filtration Efficiencies, or es you describe them, Filtrntion
Efficiencies v-. air. The filtration efficiency vs. an equivalent lerwth
of tohRcco is dependent upon the a-io-int of s-ioke presented to the plugs
and constancy of filtration efficiency dnpends upon the assumption of
cons-tant weipht of smoke constituent pr-sonted. !-e are still forT-d rig
our views on t@,.is point 9nd hope to design cxr-F@riments to test then.
!7- feel thnt so far vr- nre rroving our methodology send shernening
our witc. nn 'ht c-roblem. Ther- rre a nu-ber of other featur-s wAch
rewiLrg in-;e@ltig ntior, snch as th- depend@-nce of filtration efficiency
upon lin-pr nirflow of the raerozel fhrc-rh the filter; and we plan, -!t
some time in the fut,ire, to initi@,te st-idies into the physics of filtration
and the dependence upon all the physical chf@.Tncteristics.
In order to Drovide ourselves with suitnbly flexible apparatus
pcsre3 i'lg !) n-:nber @-f fiesirnble fe-t-lr-s, vie h-!ve designed a new pattern
9 --o@inf7 machine. It operntes under constant volume conditions and besides
enabling its to sr-okr cigarettes riechnnizally un6er reproducible conditions
of ccnstnnt ruff profilep it will be ndjurtable to n wide range of puff
conditions by suitable alteration in rge-rs, cars etc. It will enable us
to s-oke "filter Unped" Cirrarettes with the filter senaratpd from the
cignratte nnl to meazure end record by pen-recordnr the presoure changes
across the cigrxettes nnd filters individunlly !,.nd on sll six chann-16.
We can then check that conditions are cnns,-nt send see what changes in
pressure occur on proareEcive deposition of s@-oke in the filter.
The machine is at present undereoinr. exhaustive testing to reveal
design failures and necessary modifications.
So far, we have not touched on the question of unimpaired taste
and flavour ap3rt from exploring the effect of tobacco as an additive
to conventional filters in rqstoring a modicum of tobacconess to the
smoke. This aspect impinges an thot of
PROJECT 6 - Tacte -and Flavour of Smoke.
Here, the first requirement is the systematisation of the terms
CZ>
NO
BATCo document for Province of BritlSh Columbia 21 April 1999

2
L. C. Laporte, Es-. 25th April, 1958
non-porous envelope (ensured by binding it with Sellctape - the filter
tip on a cigarette hes a cork tipping which effectively makes it non-
porous) then draw resist3nce, defined as Pressure drop per linear
nJrflaw, (the pressure drop is mensured at en airflow of 1250 cc#/min#
and is then cbrrpctell for crcss-section,-d erea) varics linearly with the
length of the filter
P = _L L
V A F. L, v beini7 linepy airflow.
We call the constant, E , the Irpedance Coefficient for the filter.
!Jhen the envelope wrerpinry the filter to norous, as is usually
-.he case, then the curve ccnnecting(u)with L is n,-qrly linear for lengths
iip t@- 60 nm., Mt then curven Eway, @ and just et rreseTit we are province
-hp correctness of' the expres ion we hove derived, which includes the
1;crosity of the onper. It h,!s cxplpined n nuriter of curious smal.1
%nomtali@!s we encountered in the eerly stngco.
',I;, hrve proCrrc@ed from this to a sto-ly c!' the variation of
filtration efficiency with 1-neth for V Dirticul-r filter. 'a have shown
that filtration occurs exponenti-311y, and the curve in a true exponential
"or lengtf-s ur to ab-ut 18-20 -m.
Thus, if j0 is the s-cke Presented t. the filter, and is the
smoke passing the filter
S., _KL
0
f-nm which we derive
Filtration efficiency so - J1 1 - e_KL
S
0
whence lose (I - K1L (K = (.431.3K')
'hen we Plot loglo (1 against L, we get n. straight line for
the lengths up to 1@-20 mm. After ti4sp the filtration efficiency falls
away, and we think this is probably duo to the greater difficulty in
filtering th- remaining s@aller particles fro-- tho s-.-oke. Our ideas on
this phase ore JuFt fnrming and we w:-uld prefer not to enlarge on them
at present.
C=)
BATCo document for Province of BritiSh Columbia 21 April 1999

EMA/VC/46D
AIRMAIL 2 5 th April, 1958
L. C. Laporte, Esq., PRIIATE & '@
Imperial Tobacco Company of Canada Ltd.,,
P.O. Box 6500Y
MONTREAL 30,
CANADA.
Dear Leo,
I undergtnnd from Fir Charles, and you will have seen from
fir. Hobson's letter to Mr. Keith of 2nd !.oril, that there may now be a
full exchange of information between us on the work being carried out
on "Smoke" and its various health aspects.
I am starting the ball rolling by sending you the current
programme for the Smoke Section of the laborntories here at R.& D.
This has been cut 4own in a me, in from the full programme, which I showed
you during my visit to ;:ontreal,, because of the lack of people to carry
on all of the work therein detailed, and the current programme is
nccordingly cut down to what we can tackle. Even so, the smoke
programme covers a number or projects which are to a lesser or greater
degree inter-related and some are in abeyance or not started because of
the pressure of work on the others.
An important feature of the programme concerns the health
aspect. We feel that since no one substenr.e or ETOlip of substances can
be indicted it would be chasing a will-o'-the-wisp to concentrate on a
particular clasE of smoke constituents. The overall reduction of the
smoke constituents taken in by a smoker must reduce any danger
proportionately, if danger there be. For this reason a considerable
effort ij being put into
0
PROJECT 2 - The study of the ways in which a filter acts, in order to
produce filters of very high efficiency yet giving smoke with unimpaired
taste and flavour. Our original task was to produce a filter which,,
while possessing a tolerable draw resistance, wculd rwrova Irds tar from
the smoke. Luckily, we nearly achieved this in our first shot using
Suportex Cotton filters. We are not, however,, working on an 'ad hoe'
basis.
e have studied the variation of draw resistance of a filter
rod with length. We have been able to show that when a filter han a
BATCo document for Province of British Columbia 21 April 1999