Document G6rNm3r8oLZQgLGbqRX9GxqRx
PLAINTIFF'S EXHIBIT
TNI DOW CMBMICAL COMPANY
DOW-1997
IIIUK a icsi s as nTW
IMTUCTMi--1-2-7(21
9M ma wee* iwiiTMiMf
ACCTs 90369
wr - --...........
BmW/TkvkA
January 16. 197 m-/K-73 RMIU UUI
i/ V ^ ' V
9090001
EVALUATION OP ASBESTOS DUST EXPOSURES DURING THE MORAFXNG OF TEFLON LINED PIPE. LINED PIPE PLANT. BAY CITY. MICHIGAN
INFORMATIVE SUMtAXY WITH CONCLUSIONS
Results of eight bresthing zone sasiples taken at the Bay City Lined Pipe Plant indicate that exposures to asbestos dust during gasket application and MORAFing of Teflon lined pipe are well within the current inhalation standard for asbestos. No further control measures are needed.
l uu U U V L O
w C0"mNTlAl
REVIEWED BY
}- f fr-- 7 T
jrad
---------------------------------------------- LUJLLE--JL2
J. S. Beale, Bay City Lined Pipe Plant
J. M. Ayres, Bay City Lined Pipe Plant S. P. Marshall, Bay city Lined Pipe Plant
D. B. Semeyn, Bay city Lined Pipe Plant M. Hansen, Bay City Lined Pipe Plant V. F. Haggltt, Bay city Lined Pipe Plant J. D, Young, Corporate Safety & Loss Prevention,
566 Building
H. L. Gordon, M.D., Corporate Medical, 2030 Building A. W. Schaffer, Environmental Health Services. 2020 Building L. G. Silverstein, Chemical Biology Research, 1701 Building
G. H. Flores, Chemical Biology Research, 1701 Building CRX, 566 Building
R. M. Reitz, Bay City Lined Pipe Plant
I SI
2
PROBLEM
Gaskets containing asbaatos ara usad in tha Bay city Linad Pipa Plant on pipa linad with poly-tatra fluoroathylene (Taflon). Thaia gaskats ara placad between tha faca of tha end flanga and tha lining which is haatad and molded" (MORAFed) over tha faca of tha flanga. Since chronic inhalation of asbestos dust is known to have dalatarious effects on tha lungs, super vision of tha Linad Pipa Plant requested that tha Industrial Hygiene Section of Chemical Biology Research evaluate tha expo sure of personnel to asbestos dust while tha gaskats were being placad ovar Teflon pipa linings and MORAFed into place.
t7 (;n n a n i
CONCLUSIONS
Tne results of eight samples taken show that the expo' sures of personnel to asbestos dust are well within the current occupational health standards. No additional dust control measures ara necessary.
t
3
DISCUSSION
At seen in Figure 1, the MORAFing process consists of placing an asbestos-containing gaakat over tha TafIon linar. Tha protruding and of tha linar la than haatad with a gas-fueled torch until it bacomaa claar (watar whit**) and moldabla. A dia ia aubaaquantly clamped ovar tha end to mold/extrude tha linar over tha gaakat into a plana parallel to tha flange face. Tha fire retardant propartiaa of aabeatoa ara daairabla bacauaa relatively high taaperaturea ara obtained durinc heating of the linar, yet tha gaakat auffara little or no damage.
On December 5. 1972, eight aabeatoa dust-in-air samplea ware collected at tha Bay city Lined Pipe Plant during tha MORAFing of Teflon lined pipe. Tha aamplaa ware collected by placing two membrane filtara (in holdara) on tha lapel of the operator performing tha work. Tha filtara ware coupled in parallel with rubber tubing which waa attached to a vacuum pump. Uaing a mercury-filled manometer, tha pressure drop across the filters waa measured, in addition to tha total sample time. Four sets of duplicate breathing zona samples ware collected in total.
The filter samples were taken to the Microscopy Lab at 574 Building where the filter papers were sectioned and mounted on lNx 2" microscope slides. A clarification medium was applied to the papers to change the opaque, white paper into a clear, transparent gel. The samples were subsequently observed
^ uuuuyJU
4
under the phase contrast microscope. In accordance with the current criteria for counting asbestos dust fibers established by HIOSH (The National Institute of Occupational Safety and Health), all particles greater than five microns in length with an aspect (length to width) ratio a3.0 were counted over 20 fields. It should be noted that approximately 10* of the fibers counted actually appeared as asbestos. Total area of the 20 fields was 0.692 sq. mm. (The microscopic analysis of the samples was completed by the author.) The results of the analyses are shorn in Table 1 which also includes other perti nent data. The data listed for samples 1L and 1R are predicated on the assumption that the vacuum pump was operating for a fiveminute interval. The actual sample period is known only to be less than 45 minutes at which time the pump was observed to be inoperative from an overloaded circuit. Basing conclusions on the remaining six samples, the mean concentration is 0.073 fibers per ml of air. and the standard deviation is 0.048. within a 97.5% confidence limit, it is concluded that the breath ing zone dust concentrations are less than C.17 fibers per ml of air. These are fibers 25 microns in length with an aspect ratio 23. as asbestos.
To be meaningful, the observed values should be com pared to a standard for asbestos dust inhalation. The standard is the TLV or Threshold Limit Value established by the ACGIH 'American Conference of Governmental Industrial Hygienists).
I60000 I
5 This value is currently five fibers* per ml of air, and represents the maximum time-weighted average exposure that will produce no effect for people exposed. TLVs are based on dail> exposures of eight hours with repeated exposures throughout a working lifetime. Because the observed concentrations were well within the TLV, no attempt was made to time weight the exposures, as the exposures are unquestionably within the TLV, and no health hazard from asbestos dust is foreseen with this MORAFing operation.
Present plans call for the lowering of the TLV for asbestos to two fibers per ml air in 1976. Even at this more conservative control level, the asbestos exposures during the MORAFing of Teflon lined pipe are still acceptable.
*>5u in length, aspect ratio %3.C
-p f- ri n n n I Cr
f ig u r e 1. S e c tio n e d v ie w s o f MORAFing P ro c e s s f o r T e flo n L in e d P ip e
a wa
IA uu
:e m
'3
Im u
o
nna
X
u
a-
MORAFing o f T e flo n L in e d P ip e
68,
57
* * Assumed v a lu e
<XN
04 <N
<4,
m
LA m X
in
in in in
oo
m rr
p
d
Ae
o
** u 3
IS 04 r* <N o <N # X in CinD 0*4
m t
X
<4 04
m <0
tr o
Q
u
mG a.
51 5
X <0
4 m
<N
m m
o v0O4
a&M. IS
O Xm
ce
a u 31 r*
0* *A4i
in
m
e H CD o in * in
A IS m 04
u>.
-4
3 Z
04
u >. ae
0e4
a a
ISl|
e4 <4
o o04
n
o in m
*4
CinD
at 04
01 9
*
A
in tN
04
X O'
o
<6 o
lA in (4
14 04
4 a*
0o
o at in o (9
in o
3
<4 04
o in
*
X
mm
in 04
oX oo X o*
je 6e*
cel *rf
X
o in
<4
04 % m A* m
X in 04
*4
in
X
IS
HJlj
rA.* 04
Xm Xe f4
o lA lA
o
* in
<N
0sO4
W
m
UN
IS
eu 4
s-Q
5
4eJ e3 ou ue A
2
e J3
X0*
a ou a ew 3a m 9 au.
B
\ 4
e 04
u
e 0
14
<4 IS e
>4
e
4
04
Q.
*
w 3 r " *O4'
O4' ll
9R
a V4i
U
l
e S
nM
9u
w 1V*4i
Vi -- M
<
a a
01
*9*
U
V A
Vl C
"0 3
V u *
0 0
ue
4) U
09
-4 4J u
09
u
ve Vi Vi > A4 e <u <2 TJ a E ** 9G
01 030
ft w or a id
4 <N 44 a>nt ^
* o ** VU 40J 0
e0 9
4
u9 0
IS
9 \0
X
O'
C <U
- o
>
ee
a
9i
u a
--a
4) >
0
O 41 IS <u e4 9
G a uX GG 3 ** 0> u
eu A V
A
4*J *
o
c c c c u a.
jr
W- 2. Air Flow Rate vs Pressure Drop Cor 0.2 micron. 47 mm diameter CLLter
A ir F1ck> R a te , l i t e r s p e r m in u te
s i uuuuyjt)
INDUSTRIAL HVQIKNI SAMPLE RECORD
13-S-72-
"7- ,TSK, f7,,V
Jrcai jl y^Il&o i~
<V-?U
jQCie&MC
Tint
IfA#f IN
^ I liu u u 3>u
LLjZaou-
2 , j w.U3-". tUv.j r'M.
t-. = 0.0573} O OSVf 0,| ^g;
AP-^SSV *
.1
J&7\K. =v <
/rut\
futvi^L. jUidi:.LciicvL'f- citifeadsk
/)J--t?,9i({\.;'i7'Vh' -JcA-34 if-'-n.-*-- /util /y/ip- '7'jO............................. .....
..
V r, r<'X-.4 <J t O.OS'Tt . 0.7 rrw
A . fqji- - C.O
0-0J9.01 .cJ/rru.
g/*-3<g"
.3-JLMuu .-JlSiWfS* fcni* - b /.S'r M{*u
___________ =..0,0527, 0.0591
, O.forw.
r-...........'-fMjZ.Ag AP" >ATM|'
oMc*a
.0553 ., 0-P5&0. . 0.7 j;
&!
-
#*t '
- HJ, S /7iiri,
COM*
J'{Jpckx
lt-27'
-l
-*
r 6
f7 ? 9 /c // !~2, /3 /? /f /6 /7 /f if Sb
%
f*t* Xff.
/ 0
0 /
c
A / A.
c
c> / C
i i 0 0 A. A c
&
$7.3
lS.2.
(*) 7*
c
/
i 1 A / /
5. / 2 / -2 0 / 3/ 55& 5*3 /41 fto 141
C
C
o
A I A0 1 /
o
c
I
f
a c I o
c
It
/to
bf^
^ f^ n o n o i
(> (jTg 3L 4L-
D (5joT)1 (2
7?2r ll
i /7^ 4. C
0
*/ 5" (
6/
;/ f 6' *C /$ o
it 3
lL S'
J3 7
/f * /5- f
/&
17
l?
i? AO #
0
O I O
o o
2
X 2L 2
3 / 6
y
3G
r
*
AP< 514 #1 5vr, 5*7
^n
$
min-4 w? 4f5 ft*- 9Vf Hi
0
0
o
0 1 3
t
0
0
A 0 3 S'
L s o 1
it
/ 5*3 a
4*5-
lo*
i2_
/
5
/ /
A X
>
3 3
IS o X 2 A3
550
4*4
to* (*5* 5Zo yoi
o 0 o <9 ( o / 0
SL. 3
t
1 / a
/ 0 6
-3.
(1
550
Hp-i^
ct) ft
tM7-7iL
c/) -H O o
a
c <*0 C-5
"9