Document O10wEe2p5xwxdv9rE7NVNYV0j
E TH YL COR POR ATION
lOO PARK AVENUE BUILDING AT 41st STREET
NEWYORK 17, N. Y.
November 19, 1959
D r . R . A . Kehoe The Kettering Laboratory Eden and Bethesda Avenues Cincinnati 19, Ohio Dear Dr. Kehoe:
Subject: Precautions for Handling Tetramethyllead We are attaching a copy of precautions dated March 2, 19^-9 for handling Tetramethyllead in .laboratories. In view of recent developments, we are wondering whether or not these recommendations are still firm. From time to time we are getting inquiries about safe han dling of Tetramethyllead in laboratories and we want to make certain that we are up-to-date.
Yours very truly,
's-- _
H. K. Ball HKB:vb CC: Dr. K. V. Kitzmiller (Att.)
Mr. A. J. Baldwin
H 0002943
:t
Sa
'fci-4%- -- -V7--
-v* **,.*r"" ' ' . V".\;--f.::-'-,"'. -''>o"--^:-0c..'*c:- ."'..''* .- -. -O.' '-.- -.'- :-
fl gimiwl precaatloae fer haadliaf tetraaetfagrllea m the '
M ii t k m i M H d V mor Wadtcd Dep&rtaeet fbr t m l f tetncttgrl
' : iMtd u d SBGO Tlaid, wjtrjf rhleh la attasbad la additioa, A m
- :4>.:\:V-ftarther varaiofe abould be aade rcfardias the haadlIng f totraacthrllead
(1) The rapar pretiere'of to t m r a j U M li far greater thaau.y., that ef tetaaetfeqrlleed, beles abeeh 10 aa at 0 6., H aeu ai 25<*B, ca 760 a ah 110 0 Coaeogeeatly becauee ef lie toada aetcnrey greaUv pmntteBi wat be exerolaed la haadlinfritet Xt ahould aerar be htadlad : vlthoet adeqeete reatilatloM, aad all raaldtteaahcmld be dlapoaed of la a heod bgr dfhatlcai vith carbaatetraehlerlde and preeipltatlaei vith brealae
'' .-
(2) la addltioa bo belagcoabostiblo, tatr*aeth7lleed la
vi v
tad ea editable theraal er duaial dadc fUl
W deeeopeee vlth asplesire rloleaee Beatles tp aa opas fXaae ea dietlllatlca
' la ene essapl Aaother la the flaeblaf ef iba era rapar abare the llgoid
- ' saeh aa tabea place m atteespta te acal the arterial la agate bolbf anafe
: peaalncV alld fl*flh la the raptar la eofficleah to aet off the laetaataaeoee
'^0^0;::: deeoopealtloe ef aajr aaceat ef llqeld la ecntaet rlth 1 W Letal fr--
T^00'^ " vithla the llquld recatas fren ehanlealreactloe aa? alee iIiti!iiji late -
. 4etoaatleBe - . . -.
\:
Zf lt ahoold be neeeeearjr t aeal the Material la bolba* lt le reeeaaeaded that the bolba har vovy loas cepillarle# aad thet tha? be ceded to at leaet -60 C befare eeallaf The operatoria haaa sl^Bl b paroteeted vith heary Lama$ as ble faee bgr eafe^r gegsl or a veldes*a helset* Zf for aaf reaaco the a&terlal le te be beated^ aiiah ae for dle~ tlUatlaat aa ol bath ahould be caed rather thaa a free flaoae
__ The tetraaathyllead aa^lled h?''tui le of relatirely hlfljh parltf (abeat 99$)t aad for aoet porpoeee la aatlefactor? for uae aa le* The Ihpnrltlss preoeat are aaell aacroete ef aettqrl dalerlde aad hgrdreeesheaa aadi aa aethaaat ethaaaf aad ethjrleaa* Za the ereat that the prepeeed ee ef the eoapound reqdrea the r-- wral ef thoee iapurltiee the alajsleat eo4 eefeet w y te do thle la tgr pqaplag eff caterial tatill the repor pzeaaere ., .
.ef the resalalag Material beeeaee oentat*'p.v:^-i':;-'l;r
Sarold Soroca
SH
k'E' 00021:4 1
(1) Because of the dangervhich may arise from explosive deocmpositloa v do not make a praotlce of seeling tetramethyl lead into glass ampoules,
(2) According to information received from Dr. Kehoe, tetramethyl lead
has essentially the same toxicity as tetraethyl lead. Hence, the safe
breathing limit for tetraaethyl lead may be taken as 4 miorograms lead
per cubic foot* Compared with this value, the quantity of tetramethyl
lead used in a Geiger counter is large indeed, being equivalent to
approximately 6 mg. of lead. However, we believe that accidental
breakage of the tube would not produce a hs<h problem, since the
escaping tetramethyl lead vapor would be diluted rapidly with air to a
safe concentration. The room, of course, should be ventilated at once,
as suggested by Mr, Beckwith.
..
In handling tetramethyl lead it is important to remember that the compound is about IDO times as .volatile as tetraethyl lead. For this reason it is far more dangerous to inhale the vapors of (liquid) tetramethyl lead than those of tetraethyl lead.
(3) In Or. Sorooa' bulletin,of March 2, 1949, concerning ^Precautions
for Handling Tetramethyl Lead*, the temperatures are given as degrees
Centigrade.
.
Taken from a letter to Mr. E.K,
Locher from Dr 8. O.Rue, '
dated December 28, 194-9.
000^945
EEHXL GASOLINE CORPORATION Chemical Research Laboratory
/
/
--V-
LTD 41-28 H. B Heal
Notebooks 239, 286
July 22, 1941
Approved___ fedSL
EVAPORATION OF GASOLINE COHTAIHIEO TETRJUKEH2LLEAD AM? KBg3H*-ETEiCL LEAD ALKSELS
PURPOSE
To check experimentally the calculations in LTD 38-20
for the amount of lead vaporised in the evaporation of 0 to 10$
of a typical gasoline containing 3.15 g. Pb/gal. in the form of
different lead alkyl compounds and mixtures.
SUIfflARf
'
Tetraethyllead and M-41Q equilibrium mixture were added separately to a summer gasoline to give 3.15 g. Pb/gal. By passing air through a sample of each fuel, ten cuts of one percent each
were evaporated, collected in a trap at dry-ice temperature?, weighed by difference, and analysed for ?b by the ciithisone method.
The results on the whole wore in good agreement with the
calculated values for both fuels. She total m o u n t of lead vapori sed vas nearly identical with the predicted values, although on
going from the 1 st to the 10 th out^ the expected two-fold increase
in the load content of the cuts was not closely realised: instead,
the M-410 raixturs showed a three-fold, increase, whereas the tetra ethyllead shoved none. The amount of air required could not be
compared exactly with the calculated values (because of differences
in the pressure and temperature) but was evidently in satisfactory
agreement, and varied as predicted from the 1st to the 10 th cut.
EXPERIMENTAL
Preliminary runs, made on Metro gasoline and CFR Fuel SC-1, led to an arrangement of apparatus, shown in Fig. 1, which proved suitable for the experiment. The air, regulated by reduc
ing valve (1 ) ani outlet (2 ), was measured by the calibrated
Sargent Wet Test Meter (3). After moisture was removed in the dry-ice trap (4), the air was warmed to room temperature in the
3-ft. copper coil (5 ), and passed through the gasoline sample in the tower (6 ) on the balance (10), Calibrated weights were used.
The bulk of the cut was condensed at dry-Ice temperature in the
replaceable flask (8 ), and the final traces of lead were removed in scrubber (9 ) sontaining iodine-potassium iodide solution.
The pros sure in tower (6 ) was that of the atmosphere plus the resistance of scrubber (9 )* it was measured by manometer (7),
2
and was about 780 can. She temperature In tower (6 ) m s not con
trolled, but equalled that of the room, end varied a degree or
tvo during each run; it was measured by a thermometer In the tower,
and vas about 2 2 .5 for the first run and 24 for the second.
She glassware was washed before use with cleaning solution and dilute nitric and hydrochloric acids to remove lead and heavy metals which might interfere with the dithizone analysis for lead.
S u m e r Silver Shell gasoline was chosen for the test.
One part was treated with 3 .16 g. Pb/gal., by analysis, as tetra
ethyllead (redistilled), while another part was treated with
almost exactly the same quantity, by analysis, as M-41Q mixture.
(M-410 mixture is a random equilibrium mixture of the five methyl
and ethyl tetra-aikyl lead compounds, containing 41$ methyl
radicals, i.e. 2.8 mole nercent Me^Fb, 16 .3$ Me3Et?b, 3 5 .1$ MesEtaPb, 3 3 7/ MeEtaPb, and 12.1$"Et4Pb,)
One run was made with each fuel, as follows. The fuel
sample (about 400 g.) was placed in tower (6 ) and accurately
weighed. The approximate quantity of air required to vaporise 1$
of the gasoline (determined in pilot runs) was then passed through
the train at 0.010 to 0.020 cvu ft./min. The tower was again
weighed^ and the gasoline evaporated was determined by difference,
jrlask (b) was removed and stoppered, the condensate was brominated,
and the lead content was determined later by the dithizone method.
Flask (8 ) was replaced by another, and the flow of air was resumed for the next 1$ cut. This procedure was followed until 10 cuts
had been obtained. Finally, the iodine solution in (9) was analysed,
and the lead found therein was distributed among the 10 cuts in
proportion to their lead contents. In the evaporation of the
tetraethyllead-treated gasoline, 10 .8$ of the load vaporised was
found in the absorber, and with the M-41G-treated gasoline, 2 .5$
was found. Also, the unevaporated fuel was analysed for lead, as
a check.
~
RESULTS '
Lead recovery. - This was as follows!
Fuel treated with fetraathy.llead .
Fuel sample, g.
Lead In original sample, g.
Lead recovered! In evaporated 10$, g. In unevaporated 90$, g.
Total recovered, g.
402,4 0.4564
0.000143 0.4567 0.4568
410.0 0.4714
0.001485 0.4690 ... 0.-4705
This recovery is satisfactory in both cases, and the slight
discrepancy in the results may be ascribed to experimental error
In the analysis.
3
Lead content of cuta and volume of air used. - The observational data are given in Tables I and II. In Table I, values were assumed for the lead content of Cut 3 (obviously incorrect) and Cut 4 (lost during analysis). The values inserted were obtained by mathematical treatment based on the alignment of the remaining data. The air volumes read on the meter -were corrected to give volumes of air at the pressure and temperature of the tower. The cumulative data from the last three columns of the two Tables are plotted in Figs. 2 and 3> respectively, and are seen to be in extremely good alignment. Smooth parabolic curves vere fitted to the data, and values vere taken from these curves at even intervals, vere scaled up to 1000 g. of fuel, and are given in Table III.
TABLE I
AIR EVAPORATION OF GASOLINE CQHTAIKIHG TETRTELLEAD
Teuer Pressure about 730 mm.j temperature about 22.5
Gasoline
Lead
Cut vaporised, Air .used, content
no. g l.(aj mg.(b)
Cumulative values
Gasoline
Lead
vaporised, Air,used, vaporise*
vt. i
i.(a)
mg.(b,d
i 3.0
2.905 0.0059
0.75
2,905 0.0059
2 5.1
5.507
.0229
2.01
8.412
,,0288
3 3.7
4.474 .0068
2.93
12.886
.0403
4 4.5
5.638 (c)
4.04
18.524
.0547
5 4.5
6.426 .0214
5.17
24.950
.0 76!
6 4.0
6.20 3 .0104
6,16
31.153
.0865
7 3.5
5.730
.0141
7.03
36.883
.10 0 6
8 3.5
.088
.0137
7. 9 0
42.971
.1143
9 3.7
6.834 .0111
8.82
49.805
.1254
10
5.0
IO.I32 .0.178
10 .0 6
59.937
,1432
Total 40.5
59.937
.l432b *d )
Sample 402.4
456.4
(a) Meter reading corrected to tower pressure and temperature.
(b) 0 .0 135 mg. lead in iodine solution distributed .
to the cuts in proportion to their lead content.
(c) Sample lost.
(d) Assuming 0.0115 mg. for Cut 3 and <0.0144 mg. for Cut 4, values obtained by mathematical analysis of the data.
\ <Z 0002048
4
SABLE I
AIR EVAPORATION OF GASOLINE CONTAINING M~4lO EQUILIBRIUM MIXTURE
Tover Pressure about 780 mm.$ temperature about 24
Cut
Gasoline Vaporised,
Air used,
No. l.(a '
Lead content rag.ib)
Gasoline vaporised,
Air used,
w t. $
!.(*)
Lead vapored
1 4.0 2 4.8
2 3.5
4 4.0
5 4.4
6 4.5 7 3.4
8 4.1
9 4.5 10 4.1
3.685
4.967 3.983 4.899
5.860
6.4l6 5.401
7.608
7.190 8.280
0.0029
.1178 .0 78 2
.1101
.1194 .2088
.1545
.2157 .1930
.2062
O .98
2.15
3.0 0
3.98
5.05 6.15
6.98
7.98
9.07 10.07
3.683
8.650
12.633 17.522
23.382
29.798
35.199 42.807
49.997
58.277
0.0829 .2007
.278 9
.3890 .5084
.7172
.8717 1.0874 1.2804
1.4866
Total 41.5
58.277 1.4866
Sample 410.0
471.4
(a) Meter readingi, corrected to tover pressure and temperature
(b) O,O338I m g 0 lead in iodine soiiit:ion distributed to the outs in proportion to their lead content
TABLE III
SMOOTHED EXPERIMENTAL DATA FROM FIGS, 2 AND 3
Basiss 1000 g. gasoline vaporised in equal 1# (10-g.) cuts; gasoline contains! (A) 0.113$ lead as tetraethyllead, (B) 0,115$ lead as M-410 mixture.
Cut No.
Air used, liters, Lead vaporised, mg.
AB
AB
CD
1
9.9
9.1
0.0348
0.184
2
11.0
10.4
.0348
.223
05
cv CD
3
12.1
11.3
.0350
.263
4
12.4
12.4
.0353
.303
CD
14.4
13.2
.0355
.342
O
6
15.2
14.2
.0358
.382
7
16.3
15.4
.0358
.421
U4
8
17.5
16.9
.0363
.461
9
18.7
3.8.5
.0363
.50 1
C
5.
Comparison with calculated values. - The data calculated
in LTD 38 -lb were based on assumptions as to the vapor pressure of
the fuel, and the molecular weight of the vapors, during the
evaporation, and were made for a pressure of 760 mm, and a tempera
ture of 20. The results, shown in Table IV, Indicate that these
assumptions were not seriously in error, although the vapor
pressure of the gasoline was evidently somewhat higher than
predicted,
'
The air used in the present tests was less than predicted, owing both to the higher gasoline vapor pressure and to the higher temperatures used. The amount of air varied as anticipated from the initial to the final cut.
The total amount of lead vaporized was somewhat (about 15$) lower than calculated, indicating that the vapor pressure of the gasoline was higher than expected. In view of the very small Quantities involved, the agreement can be considered excellent. (For the calculation, the vapor pressure of the M-410 mixture at 20 was taken to be 3.0 mm.) However, the distribution of the lead between the different cuts.was by no means in agreement with the predicted values? compared with the calculated two-fold increase in lead content on going from the 1st to the 10th cut, the M-410 mixture showed a three-fold increase, and the tetra ethyllead showed practically no increase at all. There is no evident explanation for these results, unless it be assumed that the partial pressure of the lead alkyls is profoundly affected by the presence of the lower-boiling compounds in the fuel.
TABLE IV
OBSERVED AHD CALCULATED VALUES FOR AIR USED AM) LEAD VAPORISED
Basiss 1000 g. gasoline vaporised in equal 1$ (XQ-g.)
cuts; gasoline contains : (A) 0.113$ lead as tetra
ethyllead, (B) 0.115$ lead as M-410 mixture. Calculated
values from data in LTD 38-20 .
Lead vaporised, $
Air used, liters
of total in fuel
Cut
Observed
Calcd. for
A
B
Ho. A B 20 .760 m . oBsvci. Calcd, Obsvd. Calcd
Afcu
000
1
9.9 9.1
11.7
0.0031
0 .0 16 0.027
10
19 9 19.5
25.5
.0032
.047 .060
Total, 1-10 147.5 140.7 171.9
.0314 .0354 .515 .408
S/f& /PC e^ue &
H. R. Heal
BsB Distribution:
E. Bartholomew G. Edgar
Harold A. Beatty
20. E. Kurt . H. Schaefer
t, ' {Y
j*u '* '( <
i
*-- ," " ""' 'f*. ^ /` Y' ) >*4* ' <r
Yit}i*31^1<,^-riA'li}tif^ *>,(
APPARATUS FOB EVAPORATION OF LEADED GASOLINE BY AIR
*r'*r (
m
(1) Reducing valve* ;
"'
,* , " 4 1
(2) Bypass
*" fA > ` ;< ' 1\s 1 ,,4 ^ J* !t ]>**?. 1*'Ju
(3) Sargent Wet Test Meter*
f,' >f
(4) ' Drying trap at dry-ioe temperature*
,>
V, >
{5; Copper vanning coil*
1
( >>
. , v^,*
(6) Bubbling tower containing gasoline sample,, ^ F >v t>'\
(7) Mercury manometer*
>
*,i. -V,' ,,(8)' Removable flask at dry-ioe temperature*
>3,31jv;,
*
1**'
!>`,s;t St1234*67'h
^/
*>,,1,'4M<<
'*t '
'(9),. Bubbling tower containing iodine solution,`: , 3;
'>
(10) Balance.
' `.4 .< 1 t,