Document 4an8EwEmdk243gmkkv8J3g3YG

CONFIDENTIAL July 2.6, 19.^ Pr. foi;ort H. Ickardt, Direct01 'Jedleal fcoourch division Esso loucarch arsu .Dgineorirug Company r ' "OX 121 Linden j dev? Jorsoy . Dear- rector Eck-ardt: Tir.o has had wings since I received your letter or Juno Hth, conearning the organic lead compound triraethylethyl load, for I have boon trying to clear anay a mountain of unfinished work Including corrosgoodene, eo as to get away for a vacation* low that June and Dig;alike, have flown, with the exception of a few days of iho latter, 3 fool that I must not wait longer to find a suitable date, for a mooting v/ifa -;or, but must writ to you instead* otherwise, I shall bo responsible for on undue delay in dealing with this natter* I an sorry now that I did not writ to you about this promptly* Since cur initial conversation, I have conrraltod a fox? responsible persona in Ethyl Corporation, and I am in position to give you the essential toxicological information and to express uy views on the urohlon of the uso of this material* 1 had no reservation at any time In JurnlGhirg you with the toxicological facts, but I co-aid hardly talk to you Ithcut considering with you the hygienic aspects of the entire situation, I hesitated to go into the latter without consulting my associates in Ethyl Corporation, since as Ethyl*3 nodical Director I could not, in such a matter, fail to apeak to come extent for the Corporation* An it is, I am Informing hr* Scales of the Detroit Laboratory and hr, thirdock of the Sal.es Department, by confidential copies cf this letter, of what I nay, sine I must b aura that there is nc ambi-yiity in ryr words or moaning* First, v/lth reference to the essential facts on the tox5.colorical behavior of trimethylethyl lead: C D This compound, somewhat nor dense than tetraothy! load, and In round numbers about ton times as volatile, has much tho sorae toxicity and r:od of action as doss tetraethyl load, being slightly mono toxic when administered by month, considerably loss toxic (apparently loss readily absorbed) when applied upon Die shin, and somewhat more toxic (gram for gram of Pb) D o n inhaled as a vapor* Th concentration of those compounds In air, which io lot: al for rabbits exposed thereto for one hour, is of the order of 1. to i> x.r* oxpressod as fb per liter of a:Ir* CONFIDENTIAL DP* R obert S* Sclcardt - (2 ) - -Tilly 2 6 , x9#> (2) Tho foregoing minor differences in She toxicity of those tv/o coKpoiiPds have little practical significance in promoting any peal cifferoncoo In trio long-term bas.ards of occupat icnal exposure to then, since the fact of their absorption through the akin and aftor inhalation is tho roally important eonolderat3on* v'ndor thoso circumst&no os the hasard depends as much upon tho duration of tho exposure as upon its severity (3) The distribution of this compound within tho tissues of animals to which it has boen administered, both initially and subsequently, Is of tho same typo as that of tetraethyl load, as judged not by any considerable number of direct observations mado on tho behavior of trimethylcthyl lead, out rather from a comparison.of the behavior of tetraethyl and fcotraiaothyl lead, those two compounds, only, having boon investigated extensively* Second, tho potential hazard created by the substitution of tri ne bhylethyl for tetraethyl lead must be considered in two relationships: I, The hazards of manufacture Quito apart from the problems which may be presented by tho greator chemical instability of trimsthylothy1 lead as compared with tetraethyl lead (this is assumed to bo the.case, and while the Infcmotion, available to me on thin matter Is inadequate, it is a problem to bo reckoned with seriously from the hyvyvonic aspect), she real problem lies in tho greater volatility of this lead compcurd as compared with that of tetraethyl load Tho lack of an appreciable incidence of tetraethyl load poisoning In association, with the manufacture of tetraethyl laud as it has boon carried cut by carefully trained, highly capable are well supervised people In tho VhS.A*, front Dr itain and Franc (and earlier in Germany) should not delude anyone into tho belief that this is not a highly dangerous nanufaefcurIng Industry* Goxrethdng near to perfect perforinanco in tho arts of production is required to maintain those operations in cafoty, whllo tho medical and hygienic-- regiKion required to secure and portray tho cafoty of tho manufacturing personnel is cno of the most intcna.ivo..and sustained efforts that is known to industry outside of the area of atomic energy* it is difficult to anticipate all of tho problems that would ho presented by a several-fold increase In the volatility of the product to be inanufacturod* Thor is little doubt that the Fifficultios could bo overcome in the manufacturing operations, but a stop-wise development of the process,-1,c*k> a rolativoly small scale, would be necessary to tho achievement of safe methods of manufacture* It would be utterly foolhardy' to hako U30 of the prosont raaufactuning facilities for tho large-scale manufacture of trimethylothyl load* CONFIDENTIAL pr, Robert b* fckardi - (3) - *h;ly 26, 1956 II* -The hazards of the distribution and use of the product Too eoinnercial distribution of gasoline containing tetraethyl loadwifein the proacr-ibod limits of concentration has boon shows to ho "afo from tho aspect of aha exposer of gasoline 'handlers to tetraethyl load (excluding the special problem of tan]: cleaning) The factors responsible for this safety, as dorenstrated oxp -ribmentally prior to the oxtersiv use of loaded gasolinopand confirmed by experience, are those of (1) the dilution of tetra ethyl load by gasoline to such an extent that its absorption through the skin is hindered to tho practical vanishing point| and (2) the suppression of a signifleant amount of vaporisation of tetra ethyl lead from gasoline hJj containers by its dilation in a solvent (gasoline) of relatively high vapor pressure (tho application of Fault*s Law to this system foretells tho facts demonstrated by orr-jorlno-nt) It thus happens that hundreds of thousands of people `r t:-o petroleum industry handle prosent-day leaded gasoline without absorbing a practically significant quantity of load* They do, hov.-over, absorb acre lead, t?:o quantity fcoung Inslgnlfleant as ccr-parod with ether sources, while tho total lovol cf absorption is insuffieiemfc to result in a noeawrablo accumulation in tho body hi a lifetime* Too margin cf safety In tho above situation :!s aunrcciable V-t difficult to r.casur, I cannot contemplate t.ko effect of a ten-fold Increase in bn.o volatility .: the lead compound In cm -mercial gasoline without great concern, for do.suite an anticipatory approach to this problem by experimental verms, the final test cf tho safety of tho procedure will have tc bo that cf practical ouporionce* It is my considered opinion that it; -would o -unwise to incur tho risk of ovmorloncc in ostab!icklng th:C facts rtn thin natter* hot only would this bo costly in terms of experimental work of various kinds, but it ray well turn out to bo unsafe. Hack-tracking would be a difficult and costly procedure, especially from tho aspect of public understanding# I trust that this will serve to convoy lot): tho facta, which are very simple, and ny opinions, which, T hope, are equally sSnpl to follow* If 1 raise questions that require further examination I shall be glad to discuss- ther? with you* 3Incerely -yours, itA?':vr co - Vr* R. K* Scales Hr* b* ?, burdock P.lobbrC a'/' HTT K 0 0 2 0 5 0 7