Document qdmZdbjL27w5N7oe2a4ZVDRbk

s * * & Et h y l Ga s o l i n e Co i i f o r a t i -o n Re s e a r c h La b o r a t o r i e s T23 Ea s t Mil w a u k e e Av e n u e D r. R o b ert A. Kehoe De t r o i t , Mi c h i g a n A prii 27, 1938. Dear Bob: I Y/111 a tte m p t to g iv e you b elo w a summary o f o u r f i n d i n g s t o d ate on th e problem o f determ ining th e b e s t mix to use fo r th e t e s t o f th e Dayton f l e e t . I u n d e r s ta n d fro m my c o n v e r s a t io n w i t h y o u t h a t you do n o t con sid e r th e sp illa g e o f lead ed g aso lin e to be o f g re a t im portance, on account o f i t s extrem ely in freq u en t occurrence, and th a t you th in k th a t the hazard, i f any, lie s in th e day in and day out exposure o f th e f illin g s ta tio n a tte n d a n ts to th e fumes em anating from th e ta n k w hich is being f i l l e d . In a c c o rd a n c e w ith y o u r su g g e s tio n we have t h e r e f o r e c o n s id e re d t h a t th e d a t a w h ich w as o f im p o rta n c e was th e amount o f l e a d p r e s e n t i n th e 1yi c u t s o f g a s o lin e v a l o r i z e d a t room te m p e ra tu re from 0 to 10). The above m en tio n ed d a ta on th e v a p o r iz a tio n o f le a d in g a s o lin e can be o b ta in e d e x p e rim e n ta lly , and can a lso be c a lc u la te d , making re a so n ab le and ju s tif ie d assum ptions reg ard in g th e vapor pressm es o f m ix tu res o f le a d compounds and g a s o l i n e h y d r o c a r b o n s . On t h a t b a s i s th e f i r s t r e s u l t we o b ta in e d was as we e x p e c te d , t h a t th e amount o f le a d in th e v ap o r w i l l be a fu n c tio n o n ly o f th e o v e r - a ll vapor p re s s u re of th e compound o r m ix tu re o f le a d compounds in v o lv e d . More s p e c i f i c a l l y , i t does n o t m a tte r w h eth er th e f l u i d u s e d c o n t a in s some t e t r a m e t h y l l e a d o r n o n e a t a l l , and a l a r g e r am ount o f - th e s l i g h t l y l e s s v o l a t i l e compounds w ould have th e same e f f e c t as th e sm all amount o f th e more v o l a t i l e te tr a m e th y lle a d . A nother r e la te d o b se rv a tio n of im portance is th a t th e amount o f lead v a p o r iz e d i n t h e f i r s t 1% c u t i s n o t g r e a t l y d i f f e r e n t fro m t h a t v a p o r iz e d i n th e t e n t h 1% c u t , so t h a t th e a v e ra g e f i g u r e may w e l l b e u s e d f b r .com para tiv e purposes. Vie h av e c a l c u l a t e d th e s e f i g u r e s i n te rm s o f m illig r a m s o f l e a d p e r c u b ic m e te r o f g a s o lin e v a p o r, and have th e n c o n v e rte d ,,them o v er i n te rra s o f m illig r a m s o f le a d p e r c u b ic m e te r o f g a s o l i n e - a i r m ix tu r e c o n t a in in g 2% g a s o lin e v ap o r by volume as p e r your su g g e s tio n . These fig u re s a re given in T able I below: TABLE I - VAPORIZATION 0 ? LiA DED GASOLINE Lead Mix: m g r. Pb/m v a p o r d a l e ,. O b serv ed m g r. Pb/m s o f 2% ga s o l i n e - v a p o r m ix tu re Pbiie4 K-500 M-501 Dd ? b S t4 209 37 25 . 10 2 (142) (54) (41) (6) 27 4.6 3.1 1 .3 0.27 D r. R.A.Kehoe parce 2 A pril 27, 1S38. The f i g u r e s g iv e n b e tw e e n p a r e n t h e s i s i n th e se c o n d l s . s t colum n, a r e e x p e rim e n ta l v a lu e s o b ta in e d some tim e b a c k . C o n sid e rin g t h a t th e g a so lin e used was n o t o f th e com position assumed in our c a lc u la tio n s , I th i n k -th a t th e ch ec k i n d i c a t e s t h a t th e f ig u r e s we o b ta in e d by. c a l c u l a t i o n are f a i r enough fo r th e purpose o f com parison* C o n s id e rin g now t h e q u e s tio n o f w hich m ix we c o n te m p la te p u tt in g on th e m ark et, i t is E a rl' s p re s e n t fe e lin g th a t th e p re fe rre d mix w ill be e i t h e r Dd o r so m eth in g v e r y s i m i l a r . The m ix m arked M-500 i s a p p r o x im a te ly th e m a t e r i a l w hich we have now a c c u m u la ted i n l a r g e q u a n t i t i e s an d a re p r e p ared to use as i s in Dayton, or to f r a c tio n a te to any d e sire d co m p o sitio n . On th e b a s i s o f o u r f i g u r e s , Dd w o u ld g iv e a b o u t 5 tim e s a s much l e a d i n a i r as t e t r a e t h y l l e a d . Some o f t h e o t h e r m ix es w h ich we m ig h t co n s i d e r s u b s t i t u t i n g f o r Dd p r i m a r i l y f o r th e s a k e o f d e c r e a s in g th e c o s t o f m an u factu re, would ru n n o t h ig h e r th a n l.% o r 7 tim es as h ig h as t e tr a e t h y lle a d . 11-500 on th e o t h e r h an d i s 2fr tim e s a s h ig h a s t h i s l a s t h ig h f i g u r e o f 1 . 8 . The c h i e f q u e s ti o n .I w an t to p u t up to you now i s w h e th e r you t h i n k we w ould be j u s t i f i e d i n u s in g su ch a h ig h s a f e t y f a c t o r o f 250;-o on o u r e x p e r i m e n t a tio n . The c h i e f ad v an tag e o f t h a t , o f c o u rse , w ould be to b e on th e s a f e s id e i f th e m a t e r i a l sh o u ld p ro v e e n t i r e l y s a t i s f a c t o r y . 'fixe tw o d raw b ack s a r e t h a t i f t h i s sh o u ld prove to be on th e b o r d e r - lin e we m ight r e g r e t l a t e r on to have gone so f a r above w h a t we r e a l l y a n t i c i p a t e u s i n g , and se c o n d , t h a t b y u s in g t h i s m a t e r i a l we m ig h t be a la rm in g th e P u b lic H e a lt h S e r v ic e q u i t e u n d u ly . I f you i'c e l t h a t u s in g M-500 i s t h e b e s t t h i n k t o do, we c a n a r r a n g e v e r y e a s ily to have th e m a te r ia l made up in to f lu id , canned and shipped to Dayton by Ju ly 1 . I f you f e e l t h a t i t w ould be w is e r to d e c re a se th e h aza rd some w h at, we c o u ld d e c id e to c u t t h i s clown t o a f i g u r e aro u n d 3 .0 , w h ich w o u ld s t i l l be 2jg tim e s as h ig h a s Dd sEhd 1 .6 tim e s a s h ig h a s a n y th in g we contem p la te u sin g . In the l a t t e r case, th e second q u estio n a ris e s as to w hether th e m a te ria l should also approxim ate th e a c tu a l com position o f th o se flu id s we w o u ld u s e o r w h e th e r we c o u ld make up a t t h i s tim e f l u i d o f t h e same o v e r a l l v a p o r p r e s s u r e , b u t o f d i f f e r e n t c o m p o s itio n . The l a t t e r w o u ld b e o b ta in e d by m ixing M-500 w ith te tr a e t h y lle a d . Y /hile t h i s would red u ce th e amount o f w ork in v o lv e d , we s h o u ld n o t be in f lu e n c e d b y t h a t c o n s id e r a tio n , a s we a r e f u ll y p re p a re d to p u t in w hatever amount o f work i s n e c e ssa ry to make th e flu id fu lly s a tis fa c to ry fo r the t e s t . P o ssib ly another argument in favor of u sin g th is m ix tu re , how ever, i s th a t i t would c o n ta in more te tra m e th y lle a d th a n any o f th e o th e rs , and th e re fo re m ight be c o n sid e re d to g iv e us a more exacting te s t than the strip p e d m ixes. I n a d d i t i o n to th e above two m a jo r q u e r i e s , I vo u ld a l s o l i k e to have you a d v is e me p ro m p tly whe t h e r you t h i n k we s h o u ld f u r t h e r s u p p o r t o u r f ig u r e s by a c tu a l d e te rm in a tio n s of v a p o r iz a tio n o f le a d 'under th e c o n d i tio n s involved, o r w hether you co n sid er th e above fig u re s s a tis f a c to r y . I hope you w i l l f i n d i t p o s s i b l e t o l e t me h e a r fro m y o u so o n on t h e s u b je c t, s in c e depending on y o u r answ er we may s t i l l h av e a f a i r amount o f w ork to do in a c o m p a ra tiv e ly s h o r t tim e . I can a ls o send you a more e la b o r a te r e p o r t in c lu d in g a l l o u r c a l c u l a t i o n s and p l o t s , o r s t i l l b e t t e r , we c o u ld a r r a n g e a co n feren c e to d is c u s s th e whole m a tte r.