Document VGzXB77gqGXe4qjYew3NG7mOg

/ ' - ' Et h y l Ga s o l i n e Co r po r a t i o n G H KM ICAL IiE SEAR CH LA B O R A TO R Y 7 6 0 0 We s t Eic h it Mil e R o a d D r. H eb ert A. Kehoe C ollege o f M edicine U niversity of C incinnati Eden Avenue C in c in n a ti, Ohio De t r o i t ,Mi c h i g a x May 2 5 , 1940 ' Dear D r. Kehoe: Your l e t t e r o f May 15 t o D r. E d g a r, -with r e s p e c t t o s tu d y o f lea d in th e d u st and atm osphere, has b een r e f e r r e d to th is la b o ra to ry and m i l be b ro u g h t to' D r. C a lin g a e rt's a tte n tio n on h is r e tu r n June 3 . I am s o r r y t o s a y t h a t a s e a r c h o f o u r f i l e s and q u e s ti o n in g o f th e vario u s people in th e d iffe re n t la b o ra to rie s here has fa ile d to p ro v id e much i n th e way o f in f o r m a tio n i n t h i s c o n n e c tio n . The f o llo w i n g p o i n t s may be o f m ore o r l e s s v a l u e : 1 . Hr. Heron says th a t D r. Edgar has in fo rm a tio n re g a rd in g work done some tim e ago b y t h e B u reau o f S ta n d a rd s t o make a C o t t r e l l p r e c i p i t a t i o n of th e e x h a u st g a s , w hich f a i l e d to remove more th a n a sm all fra c tio n of the lead co n ten t. 2 . The E n g in e erin g L a b o ra to ry r e p o r ts t h a t i n an au tom obile en g in e u s i n g 2 c c . TEL p e r g a l l o n , 12$ o f t h e l e a d i s rem oved i n t h e l u b r i - _ e a t i n g o i l j w ith 3 c c . , 8% i s so rem o v ed . 3 . The c a rb o n m onoxide c o n te n t o f e x h a u s t gas u n d e r norm al c o n d itio n s is about 1.5 -2 $ . 4 . Inform ation is a v a ilab le as to the coiroosition o f th e aqueous con d en sate from th e ex h au st p ip e . However, th e amount o f such con densate in autom obile o p e ra tio n is n i l except under sp e c ia l condi tio n s of co ld w eather and id lin g . 5. Inform ation is a v a ila b le as to th e com position o f the so lid d ep o sits in th e e n g in e, e t c . However, i t i s b e lie v e d t h a t th e amount o f - s u c h d e p o s i t s form ed i n end hicron o u t o f t h e e x h a u s t p ip e i s , r e l a t i v e l y sp eak in g , n e g lig ib le compared w ith th e t o ta l th ro u g h p u t o f le a d . 6 . A lthough no d a ta are a v a ila b le , our guess is th a t th e r e la tiv e p ro p o rtio n s o f le a d brom ide ana le a d c h lo rid e in th e exhaust gas are ab o u t th e same a s t h e p r o p o r tio n s o f b ro m id e and c h lo r id e i n th e f u e l . D r, R. 4 Kehoe Fage 2 liay 25, 1940 7 . The b o ilin g p o in ts o f 1 ead brom ide and c h lo r id e a r e , r e s p e c tiv e ly , . 916C . and 9 50C . B o th , o f c o u r s e , a r e s o lu b l e i n w a t e r . Tie c a l c u l a t e t h a t th e v a p o r,p re ssu re o f le a d brom ide a t room tem p eratu re- i s o f th e o rd e r o f 10~ 'mm., p ro b a b ly c o r r e c t w ith in a f a c to r o f ICO, A ro u g h c a lc u la tio n from t h i s f ig u re shows, t h a t i t is q u ite im p o ssib le fo r the s a lt to be d isb u rsed as a tru e vapor by ev ap o ratio n in to th e a i r ; th e r e fo r e , i t must p r e c ip ita te , and s e t t l e o u t sooner or la t e r as a d u st. 8 . Tie do n o t se e much l i k e l i h o o d o f b e in g a b le t o i d e n t i f y t h e l e a d s a l t s as such in a m ix tu re o f d u st tak e n from th e a ir or su rfa c e o f th e ground However, an in d ir e c t a n a ly s is fo r th e w ater so lu b le le a d s a l t s should be obtainable by e x tra c tio n of such dusts w ith a lim ited q u an tity of w ater in th e com plete absence of oxygen and carbon d io x id e , 9 . I t has been suggested th a t a n a ly sis o f the w ater from sew ers and d ra in p ip e s , im m ediately fo llo w in g a r a i n f a l l , would he in o rd e r. 10. I t h as been su g g ested th a t e ff e c tiv e rem oval o f a ll m eta ls, s a lts and acid s from engine ex h au st gas w ill be o b tain ed most e a s ily by p a ssin g gas d ire c tly through a scrubber packed w ith s u ita b le m a te ria l, such as glass co tto n wet w ith w ater. 11. I t is b e lie v e d to be v ery doubtful w hether any te tra e th y lle a d ever is p re s e n t in ex h au st g as, even a t th e tim e of s ta r tin g the engine,- sin ce the tem perature reached on com pression should be q u ite s u ffic ie n t to decompose th e TEL. -- Very sin cerely yours, HAB :AMC ; c c : Dr. G. Edgar I k . G. C a l i n g a e r t H arold A. B e a tty KE" 00159 6.8