Document 7R5jQNGnKQ7aNMrZxQJZY40ZE
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Randy Istre April 12, 1990
Determination of 95% Confidence Limits as Required by OSHA
VIS1A
The analysis intervals for VCM at the 95% confidence level set forth by OSHA are shown below. The same criteria was applied to the EDC analysis; although OSHA has no such limits at this time.
0.0 to 0.5 ppm 50% 0.5 to 1.0 ppm 35% Over 1.0 ppm 25%
Eight analyses of VCM and EDC standard gases at three
different concentration levels were completed. The gases
were tested at six hour exposure intervals.
The
statistical evaluation of these analyses are shown in the
attached tables. All data for the vinyl analysis meets
the required OSHA limits. Based on the data presented,
only the upper limit of the .205 ppm EDC standard and the
lower limits of the 3.85 ppm EDC standard lie outside the
assumed OSHA concentration range and these by only .042
ppm and .115 ppm respectively. Ten blank wafers were
also tested in an attempt to determine a corrected area
for the EDC peaks. 1360 was subtracted from each area
for EDC. We need improvement on this method next year.
No further work will be done this year to verify the 95%
confidence limits of this analysis.
Randy Istre Laboratory Analyst
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TABLE I
95% Confidence Limit Determination For
Vinyl Chloride
.200 DDE! VCM Standard
1) .2287 2) . 1723 3) .2010 4) . 1917 5) .2093 6) . 1747 7) .2103 8) . 1477 9) .2063
N=9 i N=3
T=l.833 S=.0247 X=.1936 Upper limit =X + Lower limit =X OSHA Requirement
>AN=.2087
i/Y N=. 1785 =.10 to .30
. 502 DDm VCM Standard
1) ,4923 2) .3793 3) .5417 4) .4507 5) .4823 6) .4487 7) .5003
8) . 3770 9) .4927
N=9 V N=3 T=1.833 S=.0553 X=.4628 Upper limit =X + Lower limit =X OSHA Requirement=
i/vj N= .4 966 i/IN=.4290
6777
. 572 DDm VCM Standard
1) .5761 2) .4762 3) . 5783 4) . 4516 5) .6057 6) . 4751 7) . 6252 8) .4175 9) . 5703
N=9 Y N=3 T=1.833 S=.0755
X=.5307 Upper limit =X + Lower limit =X OSHA Requirement=
iA N=.5768 J/Y N=. 4846
4.02: Dt>m VCM Standard
1) 4.3920 2) 3.7852 3) 4.1339
4) 3.5750
5) 4.1498
6) 3.8572 7) 4.3101
8) 2.7435 9) 4.3142
N=9 i N=3 T=1.833 S=.5189 X=3.9179 Upper limit =X + ts/lj N=4.2349 Lower limit =X - ts/Y N=3.6009 OSHA Requirement =4.02 + 25% =3.015 to 5 025
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TABLE II
95% Confidence Limit Determination
For EDC
.205 Dom EDC Standard
1) .2180 2) .2159 3) .2530 4) . 2607 5) .2238
6) .2119
7) . 4076
8) .2659 9) .5114
N=9 ^ N=3
T=l.833
S=.1041
X=.2854
,
Upper limit = X + ts/v,N = .3490
Lower limit = X - ts/VN -- .2218
OSHA Requirement = .205 + 50% = .
. 440 com EDC Standard
1) . 5189 2) .3344
3) .5262
4) .4513
5) .4479 6) .6606
7) .4584 8) .4676 9) . 5679
N=9
4 N=3
T=l.833
S--.0910
X=.4926
,
Upper limit = X + ts/v,n -- .5482
Lower limit = X - ts/VN -- .4370
OSHA Requirement = .440 35% = . 2860 to .5940
.604 DDm EDC Standard
1) . 5994 2) .5178 3) . 7286 4) .4974 5) .5832 6) .5391 7) .5574
8) .3504
9) .5501
N=9
V N=3
T=1.833
S=.0995
X=.5470
,
Upper limit = X 4- ts/V,N -- . 6078
Lower limit = X - ts/VN = .4862
OSHA Requirement = .604 + 35% = .
3.85i oom EDC Standard
1) 3.9192 2) 3.4721
3) 3.0827
4) 2.4975 5) 3.0601 6) 2.9987 7) 3.2597
8) 2.2139 9) 3.1950
N=9
V N=3
T=1.833
S=.5000
X=3.0777
,
Upper limit = X + ts/YN = 3.3832
Lower limit = X - ts/v N -- 2.7722
OSHA Requirement = 3.85 + 25% = 2
VVV 000017856