Document emXzZOYzkmM0K7XR1XpMdZoEp
AIRBORNE LEAD-CONTAINING DUST AND PUKE FROM THE USE OP LEADED CU T-OFF WHEELS ,
B y: S t a n le y D . M a rk,.-J r
"
M anager, T e ch n ica l Bran ch
Bonded A b r a s ive s D iv is io n
' Th e Ca r b or u n d u m Com pan y
N ia g a r a F a l l s , New Yo r k
INTRODUCTION
I t I s common p r a c t i c e i n t h e a b r a s i v e i n d u s t r y t o u t i l i z e
m a t e r ia ls c a lle d f i l l e r s a s in g r e d ie n t s in o r ga n ic-b o n d ed a b r a s iv e s
Th ese f i l l e r m a te r ia ls u s u a lly are in o r ga n ic in n a tu r e , A ge n e r a l
r e vie w o f f i l l e r s and t h e ir p r in c ip le s o f o p e r a tio n i s p r o vid e d
f\
b y R o b ie'," i
.
I t i s g e n e r a lly b e lie v e d t h a t le a d an d i t s com poun ds
im p a r t d e s ir e d p er fo r m a n ce c h a r a c t e r is t ic s t o bon d ed abra s ive
a r t i c l e s ? F o r e x a m p le , U0S ? P a t e n t # 2 , 2 5 8 , 77^!- d a t e d O c t o b e r l lj . ,
194-1 d i s c l o s e s t h e u s e o f p o w d e r e d l e a d , le a d a l l o y s , a n d
o th e r lo w tem p er a tu r e m e ta ls a s f i l l e r s fo r o r g a n ic bon ded
a b r a s iv e s . Th ese f i l l e r s su p p o sed ly fu n ct io n a s lu b r ic a n t s
d u r in g th e c u t t in g or a b r a d in g p r o ce ss t o r ed u ce h e a t g e n e r a t io n
and t o exte n d a b r a s iv e l i f e . W id esp rea d u sa ge o f le a d and i t s
com poun ds a s f i l l e r s in bon d ed a b r a s iv e s h a s n o t o c c u r r e d , h owever
p r o b a b ly b eca u se o f in d u s t r ia l- h y g ie n e p r o b lem s, to th e manu
fa c t u r e r as w e ll a s to th e u se r ,w h ich are a s s o cia t e d w ith
h a n d lin g o f le a d f The stu d y d e s cr ib e d in t h is p a p er was u n d er
ta ken to d e fin e th e n a tu re and e xte n t o f th e h e a lth h azard
^" ^ N. ? ,, E o b ie , "Why R e s in o id W h eel F i l l e r s " , " G r in d in g a n d F in is h in g " V o l. 7 N o, 1 2 , D ecem b er , 1 9 6 1 , p p .y4 .-lj.6 j.
K f 0003488
-2
p r e s e n t e d d u r in g t h e u se o f le a d e d c u t - o f f w h e e ls under* co n d itio n s o f no v e n t ila t io n , as o cc a s io n a lly occu r in th e fie ld .
COMPOSITION OP TEST WHEELS
S e v e r a l s e t s o f r e s in -b o n d e d c u t - o ff w h eels w ere p r e p a r e d f o r t h e s t u d y . T h e w h e e ls w e r e a l l 1 6 " i n d i a m e t e r b y l / 8 '*
t h i c k . One s e t o f w h e e ls c o n t a in e d o n ly c r y o l i t e a s f i l l e r .
I n th e o t h e r s e t s o f w h e e ls , e it h e r le a d c h lo r id e (P b Cl2 ) o r
a le a d - t in so ld e r
Pb - 2 Sn) r e p la c e d p a r t o r a l l o f
th e c r y o lit e so th a t le a d co n ten ts o f
6 $ , an d 12 $ o f t h e
t o t a l w h e e l co m p o sitio n w ere in t r o d u ce d . The c u t - o ff w h eel
co m p o sitio n s w h ich w ere in v e s t ig a t e d in t h is s tu d y a r e shown
ill T a b le 1
l *T^V. ''.
*
; ID E N TI P I CAT ION i
\
i No Lea d
; 3 - P b Clo \ 6 - P b Cl2
| l2 - P b Cl2
j1.
!i | jl
| 3 - So ld e r ! 6 - So ld e r |12 - S o l d e r
| t;
t;
l
WHi2L COMPOSITION - WT. $
Ab r a sive |
i
Kesin . C r y o lit e 1
68 i
I 16 !
' 16
?b Cpd 0
5
i
t
jj
68
2.6 12
kf
168 16 8 8
68 16 0 16 !
:
J6 8
16 12
*\ *4
68 16 8 8
68 16 0 1 16
---------- ;-----
TABLE I . CU T-OFF WHEEL COMPOSITION
- 3-
Jv-*>; '
TESTIN G PROCEDURE
A l l c u t t i n g o f f o p e r a t io n s wer-e c o n d u c t e d w it h , a s t a n d a r d
c h o p p e r - t y p e c u t - o f f m a ch in e a s shown in F ig u r e 1 No c o o la n t
w a s u s e d Th e w h e e ls w e r e o p e r a t e d a t 3 3 ^0 RPM o r 1L{ .,0 0 0 SFPM
wh en a t I 6 n in d ia m e t e r 0 The t e s t b a r s w er e 1 - 1/ 8" in d ia m e t e r
an d w ere com posed o f C1020 s t e e l w h ich h ad b e en c e r t i f i e d b y
th e ven d or t o co n t a in n o le a d . W ith th e e x c e p t io n o f on e r u n ,
; t sv> ^ w e r e c o n d u c t e d w i t h o u t v e n t i l a t i o n o f t h e m a ch in e
la eh in e was lo c a t e d in a room 62 fe e t b y 31 fe e t . i_.
. f e e t - No g- e n e r a l v e n t i l a t i o n o f t h e r o o m o c c u r r e d
d u r in g a t o s t r u n . Betw een t e s t s , t h e d o o r s t o th e room were
o p e n e d a n d t h e fu m e e x h a u s t s ys t e m f o r t h e r oom was t u r n e d
on t o c l e a r t h e a i r o f a c c u m u la t e d d u s t a n d fu m e As a f u r t h e r
p r e c a u t i o n a g a i n s t h a v in g r e s i d u a l d u s t an d fu m e fr o m a p r i o r
t e s t a ffe c t th e cu r r e n t ru n * th e w h eels w ere t e s t e d in o r d e r
o f in cr e a s in g le a d con ten t
-
Also shewn in F ig u r e 1 a r e th e two e le c t r o s t a t ic
p r e c i p i t a t o r d e v i c e s u s e d t o c o l l e c t s a m p le s o f d u s t an d fu m e
fr om room a ir Th ese d e v ic e s d raw a i r a t a known r a t e t h r o u g h
a m e t a l l i c t u b e w h e r e u p o n fu m e a n d d u s t a r e c o l l e c t e d b y
e l e c t r o s t a t i c m ean s Th e fu m e a n d d u s t a r e s u b s e q u e n t ly
a n a lyze d t o d eterm in e le a d co n te n t a cco r d in g to p r o ce d u r es
""(2 ) e s t a b lis h e d b y th e Am erica n Co n fe r e n ce o f G overn m en ta l H y g ie n is t s
''D e t e r m i n a t i o n o f L e a d i n A i r - A S i n g l e E x t r a c t i o n , M ix e d Co lo r D ith io zo n e M ethod" , Ap p roved J an u ary 2 , 1951 b y t h e Com m ittee on S t a n d a r d 'M eth od s, Am er ica n Co n fe re n ce
o f Govern m en tal I n d u s t r ia l H ygien ists
*4
Th e le a d c o n t e n t o f t h e sa m p le i s t h e n e x p r e s s e d a s m illig r a m s
o f le a d p e r cu b ic m eter o f a i r . Th e Am erica n Sta n d a r d s
A s s o c i a t i o n ^ ) e s t a b l i s h e d i n 19I4.3 t h a t t h e m axim u m a l l o w a b l e
c o n c e n t r a t io n o f le a d in a i r wh ich , w a s b r e a t h e d b y human b e in g s
t o be C .l$ m illig r a m s p e r cu b ic m e te r . T h is fig u r e was m o d ified
a t the
m eetin g o f th e Am erican Co n fe r e n ce o f G overn m en ta l
I n d u s t r ia l H yg ie n is t s w h ich m et in
p e r c u b i c +L*/;nW.v..ojq -
rJ..i-v.-0- e ~ ov*>r-vo.**,<*? 0.v**vt p r e c i p :
fCc-- V.-jV*mm: ~v*.
vop> *1^ T h e d
Lo u lsi t o 0 .2 0 m illig r a m s
fr om s a n d s s c o lle c t e d from t h e d e v ic e lo c a t e d w it h in 6 W t o 8" e <? l o s s T h e s e c o n d d e v i c e w a s u s e d t o c o l l e c t
a i r sa m p les a t a p o in t a p p r o x im a t e ly 6 f e e t from t h e c u t - o f f
w h e e l t o d e te r m in e g e n e r a l room co n t a m in a t io n fr om t h e t e s t s .
The in ta k e to th e d e vice lo ca t e d n ea r th e o p er a to r was
p o s it io n e d t o p r e v e n t la r g e p a r t i c le s from f ly i n g d i r e c t l y
in to th e c o lle c t o r tube*
RESULTS AID DISCUSSION Th e d a t a on a i r co n t a m in a t io n r e s u lt in g fr om th e t e s t i n g
o f le a d e d c u t - o f f w h e e ls are su m m arized in T a b le I I . As ca n b e see n in th e t a b le * m ost o f th e t e s t r e s u lt s w ere co n fir m ed b y r u n n in g th e w h e els a g a in d u r in g th e secon d d ay o f t e s t in g . V a r ia t io n in t e s t in g tim e o ccu r r e d b eca u se o f e le c t r i c a l d i f f i c u l t i e s . T h e l e a d c o n c e n t r a t i o n o f 0 . 2 ij. m i l l i g r a m s p e r
( 3 ) Am ori-an Sta n d a r d "A llo w a b le C o n ce n tr a tio n o f Lea d and C e r t a i n o f i t s I n o r g a n i c Co m p o u n d s" Z 37 . l l - 1 9 ^ 3 j A p p r o v e d S e p t e m b e r 1 6 * 1 9 ii-3
5 ><
cu b ic- m otor o f a i r w h ich o ccu r r e d d u r in g th e seco n d t e s t o f th e u n le a d ed w h e e l ca n n o t be r e a d ily e x p la in e d * I t i s su p p osed t h a t t h is h igh va lu e o ccu r r e d b eca u se o f r e s id u a l lea d e d d u s t ly i n g in t h e v i c i n i t y o f th e c u t - o f f m ach in e from t h e p r e vio u s d a y?s ru n * O th erw ise^ th e d a t a seem lo g ic a l*
? 1-JHk b L il ID E N TI F ICATI O N
TEST TIME | I I I MINUTES |
TEST CONDITIONS
i AIRBORNE ""
ILEAB IN | MU./ m3
| Hone
30
l Lo Lead ?
(1st Day i (2 r .d .D a yi
18 2o
i 3 ~ PbCI? w
(1s t Day i ( 2n d Day {
21 21
5 3~ So ld er .
'
:i 6 ~ ? h C l2
? 1 6 -S o ld e r :
(1s t Day (and Day
:
(1s t Day ( 2n d Day
'
(1 st Day (2nd Day
17 2>
3k 0
21 22
1 2 ?b Clo l i s t Day
20
. *" ( 2 n d D a y . 15
1 2 o So ld er ( 1 s t. Day ( 2n d Day
28 0
X2 So ld er
7*5
! B a c k g r o u n d S a m p le jj 0 .0 0 2 [j
| 1 2 0 C u t s N o V e n t i l a t i o n O.Cij. 120 Cu ts-H o V e n t ila t io n 0 *2 4
120 Cu t sNo V e n t ila t io n 1 1*16 120 Cu ts-N o V e n t ila t io n 1 1*2 6
120 Cu ts-H o V e n t ila t io n 0 .6 8 120 Cu ts-N o V e n t ila t io n 0 .9 3
120 Cu ts*N o V e n t ila t io n 1.7 0
--.
120 Cu ts-N o V e n t ila t io n 2 .0 1 120 Cu ts-N o V e n t ila t io n 2o2b
120 Cu t s -N o V e n t i la t i o n 7 c5 ? 120 CutsoNo V e n t ila t io n I okp
120 Cuts^ No V e n t ila t io n 5 o32 a-
8 0 C u t s - V e n t i l t ! on On 0 .10 0
........... -- 11" "--*h1 j'T" >*--
TABLE I I * SUMMARY OF TEST RESULTS
H Z 0003492
S.V * g j g ^ g f f y ' v . T ' '
S r # -
In a d d it io n to th e co n ce n tr a tio n o f le a d in a ir ,
co n s id e r a t io n m ust be give n to th e p a r t ic le s iz e o f lea d ed
d u s t when e v a lu a t in g i t s s ig n ific a n c e a s a h e a lt h h azard#
P a r t ic le s la r g e r th a n $-10 m icron s a r e n o t r e a d ily in g e s t e d
in t o t h e human b o d y, and n o r m a lly a r e e x p e lle d in e x p e ct o r a n t
Oj? u 'y Ou 2? m e a n s i T h e f i n e p a r t i c l e s o f l e a d m a t e r i a l s
c o n s t it u t e th e h e a lt h h azard # A secon d t e s t s e r ie s was ru n
t o d e t e r m in e p a r t i c l e s i z e o f t h e l e a d e d d u s t a n d fu m e
e m it t e d d u r in g t h e t e s t in g o f c u t - o ff w h e e ls , Tw elve r u n s
were con d u cted in a m anner s im ila r to t h a t d e s cr ib e d a b o vea
D u s t s from t h e s e t e s t s w e r e a n a ly s e d t o d e t e r m in e p a r t i c l e
s i z e # On t h e a v e r a g e , 81$ o f a l l d u s t fr o m t h e s e t e s t s w a s
le s s th a n 10 m icron s in s iz e # F u r th e r m o r e , a n a ly s is o f t h is
fin e m a te r ia l r e ve a le d t h a t m ost o f th e le a d was in t h is
p o r t io n o f th e sa m p le, and r e la t i v e ly l i t t l e o ccu r r e d a s
p a r t i c l e s l a r g e r t h a n 10 m icr o n s #
Th ese t e s t s c le a r ly d em on strate t h a t th e u se o f lea d e d
cir b -cff 1
U'OtJwl;*S 1
o p era tor
fu m e i s
o f t h e le a d in t h e human bod y# Th e in d iv id u a l t e s t shown a t
th e b ottom o f T a b le I I in d ic a t e s t h a t p ro p er v e n t ila t io n
r e d u c e s a i r b o r n e l e a d c o n t e n t b e lo w t h e m axim um a l l o w a b l e
c o n c e n t r a t io n o f 0 ,,2 0 m illig r a m s p e r c u b ic m eter #
.
H 0003493
CON CLU SION S
1 . Lead ed c u t - o ff w h e e ls a r e a h ea lth , h a za r d ,
e s p e c ia lly to th e o p era to r,,
2 . P rop er v e n t ila t io n can red u ce th e h e a lth h a za rd ,
p r o b a b ly t o w it h in s a fe lim it s .
.
3 . M a n u fa ctu r e r s o f le a d e d c u t - o ff w h e e ls sh o u ld in fo r m
t h e ir cu stom ers o f th e h e a lth h azard s in vo lve d and
sh o u ld in s t r u c t them in th e u se o f p r o p e r v e n t ila t io n
and o th e r in d u s t r ia l h ygien e m easu res t o a vo id a d ver se
h e a lt h e ffe c t s t o o p e r a tin g p e r so n n e l.
a r*^f~
p rv - y rr-TKT rVC
r i D l ' i - i i~ i
The t e s t in g p rogram d e s cr ib e d in t h is p a p er was a rra n ged
b y 1-I r . E . A . B a u m g a r t n e r o f T h e Ca r b o r u n d u m Co m p a n y. S a m p le s
o f a ir b o r n e d u s t an d fu m e w e r e c o l l e c t e d an d a n a ly z e d b y t h e
I n d u s t r ia l H ygien e F o u n d a tio n o f Am e r ica , I n c o r p o r a t e d , and
b y th e K e t t e r in g L a b o r a to r y, C o lle g e o f M ed icin e, U n iv e r s it y
o f Cin cin n a ti ,
'
F e b r u a r y , 1 9 &4-
K 0003494