Document 6BGx5LM6DxpD63kERMx4pjOV6

FILE NAME: Ford (FD) DATE: 1970 DOC#: FD156 DOCUMENT DESCRIPTION: Internal Report - Establishing the Nature of Particulate Emissions from Brake Lining Wear --LCJI Till- C? ?J FBCM BRAKE LINING WEAR - - i w-- ^ vaX O ^`he w earing dawn o f d r a k e l i n i n g on v e h i c le s c a n r e s u l t i n th e e m issio n o f wear dust in to the atm osphere. About 100 g of c h ry s o tile asb esto s per y ear are v crn from th e lin in g s o f th e average c a r. This amounts to about 11,000 to n s p er year in th e U nited S ta te s, concentrated in regions of high vehicle population d e n s ity . The t o t a l q u a n tity o f w ear d e b ris , in c lu d in g th e o th e r c o n s titu e n ts b e s id e s a s b e s to s , may am ount t o 1 l / 2 to 1 2 /3 tim e s t h i s am ount. T h is q u a n t ity i s small re la tiv e to o th e r p a rtic u la te em issions a ttrib u ta b le to v e h ic le s: ex h a u st p a r t i c u l a t e s (4 0 0 ,0 0 0 to n p e r y e a r) and t i r e - t r e a d w ear (700,000 to n s p e r y e a r y. However, s in c e a s b e s to s f i b e r h a s b e e n im p lic a te d a s a c a rc in o g e n , th e p o te n tia l hazard from b rak e lin in g w ear d e b ris could be d is p ro p o rtio n a te to i t s q u a n tity . There a re many q u e s tio n s re g a rd in g th e d is p o s itio n , p r o p e r tie s , and p h y sio lo g ical e f ie c ts o f brake lin in g wear d eb ris about w hich ve have l i t t l e in fo r m a tio n . Some o f th e s e a r e a s where know ledge i s la c k in g a r e l i s t e d b elo w . The c/o-ect o f th e program o u tl in e d h e r e i n i s t o answ er some o f th e s e q u e s tio n s i n o r d e r t o form a r a tio n a l b a s is f o r ju d g in g th e e x te n t t o which b rak e lin in g w ear p ro n u cts m ight be co n sid ered a community h e a lth h a z a rd . In fo rm atio n Which i s Lacking 1 Some o f th e wear p ro d u c ts from b ra k e l i n i n g a c c u m u la te s on w heel p a r t s and, in th e case o f drum b r a k e s , some i s r e t a i n e d w ith i n th e drum . The fr a c tio n which i s em itted to the atm osphere is n o t known. 2 . Some o f th e e m itte d w ear p r o d u c ts w i l l s e t t l e q u ic k ly an d some may rem ain a iro o rn e . The n e t tli n g c h a r a c te r i s t ic s and p a r ti c le s iz e d is tr ib u tio n o f e m itte a w ear p ro d u c ts i s n o t known. _) une fib ro u s asbestos p a rtic j.e s in wear dust could be p a rtic u la rly 8003 0227 O C.' - ' _ '> ^_... L*iCi vs'C'w cuo 13 x i c r c u s a s o e s u c s (ir.e reT .air.ifer OxlsIT CmS U Z h a v in g beer. decomposed to n o r.-fib ro u s d u s t) t h e r e i s some c o n tro v e rs y on t h i s m i n t . F u rth erm o re , th e number of f i b e r s , r a t h e r th a n th e -weight, may be none s i g n i f i c a n t . The number of f ib e r s per u n it w eight o f wear p ro d u cts and t h e i r size d is tr ib u tio n are not know. 4 . The organic in g re d ie n t in brake lin in g could, upon p y ro ly s is a t th e f r i c t i o n i n t e r f a c e , produce c a r c in o g e n ic compounds. I t i s n o t known w h e th e r such compounds a r e p r e s e n t in w ear d e b r is , and i f so , i f th e y would promote a c a rc in o g e n ic reactio n in the lungs. 5- The long term p h y sio lo g ic a l e f f e c t o f decomposed asb esto s d u st i s n o t known. The o n ly b io lo g ic a l study o f t h i s m a te r ia l found in th e l i t e r a t u r e i n d i c a t e s t h a t c a lc in e d a s b e s to s h as p ro d u ced a c u te t o x i c e f f e c t s when i n j e c t e d in m assive doses in to anim als. The amount of decomposed a sb esto s which co u ld be d i s trib u te d to th e atmosphere from brake lin in g ,w e a r is u n lik e ly to be g re a t enough t o cause any such a c u te e f f e c t in th e p o p u la tio n . No in f o r m a tio n h as b e e n found r e la tin g to its .lo n g term carcin o g en ic p o te n tia l. Experim ental Program Brake lin in g w ear d e b ris w i l l be c o lle c te d d u rin g c o n tro lle d sto p s on a b ra k e dynam om eter. The t e s t cy cle w i l l be s e l e c t e d t o c o rre s p o n d t o m o d erate b ra k in g c o n d itio n s , say a d e c e le r a tio n r a te o f 8 to 10 f t / s e c 2 from 40 o r 50 m i/h r . Experim ents w ill be done w ith both d is c b rak es and drum brakes w ith th e wheel in p la c e and w ith r e a l i s t i c a i r flow o v er th e b ra k e . T h is t e s t may he combined w ith o t h e r dynamometer t e s t s o f b r a k e l i n i n g p e rfo rm a n c e . M easurem ents w i l l b e made o f brak e lin in g w eight lo ss due to wear, and th e fo llo w in g samples w ill be c o lle c te d d u rin g m u ltip le dynamometer sto p s: 1 . Tonal wear d e b r is c o l le c t e d on th e w heel and i n th e drum w i l l be measured fo r a d eterm ination o f th e f r a c tio n em itted to the a i r . 8003 0228 d c , L X l L." "\v i. A Ti S i i \ -- C> W .1 u ^ u .U v V 1 V-, -- . h eex s o f p a p e r t o g e t some idCHi Of "t-IiC pCrX--Oli 0 X^lcr 0TTxl.X"t<0C. G.X..TX V'ixj.C.D. SOXu_^cr. Q^l.ic k iy . The q u a n tity o f c iist c c lle c x e c or xh_s sxx.xle xs exp ected xc oe v ery sms,11, and p e rh a p s n o t meaSUrUole, Since a XCXX Ox o n ly a gnaix c r XXC Ox V6a2* d u s t w i l l b e g e n e ra te d per day o f xesxirg. S&moles o f a ir b o r n e dusx w i l l be c o lle c x e d on a 0 .2 m icron membrane f i l t e r a t xhe p e rim ex er o f th e f i e l d o v e r w hich s e t t l e d sam ples a r e o b ta in e d . The a i r samoles w ill be lo cated ax a p o sitio n in d ic a te d by a lig h t beam to have a high concenxration of dust and a t a d ista n c e from th e brake such t h a t th e a i r v e lo c ity has dim inished somewhat. P relim in a ry ex p erim en ts w ill be n ecessary to develop e f f e c t i v e and m eaningfu] sam p lin g te c h n iq u e s and xo d eterm in e how much sam ple can be c o lle c te d p er s te p . I t i s p o s sib le th a t s e v e ra l days o f dynamometer I n e stin g w ill be re q u ire d xo c o l le c t s u f f ic ie n t sam ple. The sam ples c o lle c x e d on th e membrane f i l t e r and th e s e t t l e d sam ples w ill be examined by e le c tro n m icroscope to determ ine th e p a r tic le siz e d is tr ib u tio n and th e number o f f ib e r s p er u n i t w eight o f each f r a c tio n . An a tte m p t w i l l he made t o a n a ly z e e x t r a c t s o f wear d u s t f o r c a r c in o g e n ic o rg an ic compounds, such as h e n z (a )p y re n e . The q u a n titie s o f sample are ex p e c te d to be s m a ll, so th a n t h i s m easurem ent may n o t he p r a c t i c a l . The m ost l i k e l y so u rc e o f sam ple f o r t h i s a n a ly s is w i l l p ro b ab ly be th e m a te ria l c o lle c te d on th e wheel p a rts, since only a sm all fra c tio n of th e a ir-e m itte d d u st w ill be c o lle c te d . L iq u id -s o lid o r liq u id - liq u id chrom atography w ill be employed f o r th e a n a ly s is . To e n s u re t h a t th e m easured f r a c t i o n o f worn l i n i n g w h ich i s e m itte d t o th e atm osphere i s r e a l i s t i c , m easurem ents c o u ld be made of th e amount o f brak e D ining w ear debris, accum ulated on th e w heels and in xhe drams o f v e h ic le s brought in to d e a le rs f o r t h e i r f i r s t b rak e r e lin in g , and th e amounxs c o lle c te d compared xo xDn-o amount o f l i n i n g worn aw ay. T h is v.L H be done o n ly i f t n e r e s u l t s ox 8003 0229 ( 'e. enough sam ple f o r b i o l o g i c a l s t u d i e s . The k in d o f an im al t e s t and tile la b o r a to r y t o do i t would be e s ta b lis h e d by c o n s u lta tio n w ith an e x p e rt in th e f i e l d , e . g . , x . J . S e l i k o f f o f M t. S in a i h o s p i t a l in New Y ork. The ex ecu tio n o f th e proposed experim ents w ill re q u ire a co o p era tiv e e f f o r t among th e Chemical E n g in eerin g D epartm ent; th e M echanical R esearch D epartm ent, f o r th e b ra k e dynamometer s e t-u p and f o r sam pling a s s is ta n c e ; th e T ec h n ical . S ervices Departm ent, fo r p a rtic le an a ly sis and an a ly sis fo r organic carcinogens; and the Chem istry D epartm ent, fo r a s s is ta n c e in e s ta b lis h in g sampling te c h n iq u e s. I t is ex p ected th a t no mere th an ab o u t 2 man-months o f e f f o r t w ill be re q u ire d t o com plete th e descrioed sample c o lle c tio n and p h y sic a l and chem ical an aly ses of wear du st. Roy L. G ealer 8003 0230