Document rxBvJo7MV9rwemJkqox2VDrK0
CONCLUSIONS:
Relative to dust exposures from Graph, if1 Tables on Pages 8 9:
1. "Thermobestos" insulation blocks should not be fabricated when using only the original downdraft exhaust ventilation.
2. "Kaylo" insulation blocks could be fabricated safely when using only the original downdraft exhaust ventilation if existing leaks, observed on the #1 band saw, are corrected.
3. "Kaylo" insulation blocks definitely may be safely fabricated when using the entire exhaust ventilation facilities now available, i.e., hoods above the blocks as well as below.
From Graph #2 Tables on Pages 8 9:
1. Methods of handling "Thermobestos" blocks (preparatory to sawing) and scraps (after sawing) contribute greatly to specific individual exposures as demonstrated by the following facts:
a. The fabrication process, which always begins at the 22 band saw with the simple cutting of each 18" x 36" x 4" block into three^smaller blocks about 18" x 12" x 4", is normally the least dusty of all the fabrication operations as revealed by the samples taken on 24 Jan 1963.
b. However, on 6 Mar 1963, this operation was revealed as being one of the dustiest, regardless of the ventilation being used.
c. There was only one major variable between the samples taken on the two dates, i.e., the method of handling the blocks preparatory to sawing. Consideration of the procedure used on these dates reveals: (1) that on 24 Jan 1953, the blocks were rolled up to the saw after having been removed from their shipping cartons and stacked on a "dolly" for easy individual removal and (2) on 6 Mar 1353, the blocks were not removed from their shipping cartons until needed by the worker. A large amount of dust is produced when blocks are removed individually from the cartons as a result of the natural abrasion produced when one block is pulled over the surface of the other. Consequently, the dust concentrations on this date at this location were greater than normal.
2. The supplementary overhead ventilation (added since the time of the preceding two reports) does successfully reduce the dust exposures. However, it does not reduce "Thermobestos" cust exposures to within safe acceptable limits when cutting radii.
From Graph 23 Table on Page 9:
1. "Carey-Temp" dust concentrations for each exposure was substantially greater than the comparable "Thermobestos" dust concentrations and in excess of even the most lenient TLV established for human exposures, i.e., 50 mppcf of air.
7.
2. The existing exhaust ventilation system as installed on both band saws is incapable of reducing the dust hazard, associated with the fabrication of "Carey-Temp", to within safe acceptable limits, i.e., 20 mppcf of air.
Relative to the exhaust ventilation system:
1. The duct velocity in the downdraft ventilation system on both band saws is far below the recommended value of 4000 fpm.
2. The duct velocity in the overhead ventilation system on both band saws is equal to or more than the reconmended value of 4000 fpm.
3. The velocity in the downdraft ventilation systems for both band saws could be increased by patching all holes, leaks, etc., now in existence.
RECOMMENDATIONS:
1. Do not fabricate 18" x 36" x 4" "Carey-Temp" or "Thermobestos" insulation materials unless:
a. The atmospheric dust problem can be reduced to below 20 mppcf of air through the use of improved ventilation techniques or repairs to the existing system, or
b. Ihe manufacturers of the two makes of insulation materials are able to produce a product which will not release, upon fabrication with a band saw, dust concentrations in excess of 20 mppcf of air.
RE?:hi 23 October 1963
Submitted
A 02 4 7 1
INDUSTRIAL HYGIENE SURVEY Evaluation of Atmospheric IXist Conditions at the Construction Insulation Shop
Table #1 Atmospheric Dust Concentration Data
Collected When Using Only Partial Ventilation,i.e., Only Below the Blocks
Date
25 Feb 63 24 Jan 63
6 Mar 63
25 Feb 63 24 Jan 63
6 Mar 63
Cutting Edging Insulation Blocks
Type of Material
Kaylo Thermobestos
II
Kaylo Thermobestos
It
Description of Location
#1, i.Yel ., SoIuI th SidIIe oIfI thIIe HI2I BaInfd SaIIw If II II H H H H II
#2, i.e., South Side of the si Band Saw
#2 *i
11 |f ,r 11 " 11 n
g2 it
M H ii it ii ii I*
Concentration in mppcf
9.32 10.00 51.50
17.92 26.36 42.70
Date
Mar 62 25 Feb 63
Mar 62 24 Jan 63
6 Mar 63
Mar 62 25 Feb 63
Mar 62 24 Jan 63
6 Mar 63
Cutting a Radius on Insulation Blocks
Type of Material
Kaylo
tl
Thermobestos
If ft
Kaylo
II
Thermobestos
II II
Descr:.pticn of I-CC--'ti on
#3, i.e., South Side cf
42
if 3, tr
It tl If II II
#3, it
II If 11 If tl
#3, n
11 II II If 11
#3, ti
II If II 11 If
Saw
ti II
ti If it It
ti II
#4, i.e., South Side of the .7 4. Band Saw
#4, ft
II II II If II M II
II 11 11 tl If II II II
#4, II #4, If
If 11 If tl If If ft ft II If tl tl It II
Concentration in r.ppcf
17.10 3.39
101.40 69.59 36.82
3.06 29.35 63.30 65.69 70.00
A02472
Date
6 tor 63 26 Feb 63
6 tor 63 26 Feb 63
Table #2 Atmospheric Dust Concentration Data
Collected When Using All Available Ventilation, i.e., Both Above Below the Blocks
Cutting S. Edging Insulation Blocks
9.
Type of toterial
Thermobestos Carey-Temp
Thermobestos Carey-Temp
Description of Location
#la, i.e., South Side of the 2 Band Saw It II II II II II II If
#2a, i.e., South Side of the HI Band Saw
g2a
l II It ** 1*
Concentration in mppcf
30.20 51.70
17.59 58.20
Date
6 tor 63 6 tor 63 26 Feb 63 26 Feb 63
Cutting a Radius on Insulation Blocks
Type of toterial
Thermobestos
Thermobestos Carey-Temp
Carey-Temp
Description of Location
#3a, i.e., South Side of the ?2 Band Saw #4a, i.e., South Side cf the si Band Saw
II II II II II If II #5a, i.e., .'forth Side cf the =1 Band Saw
Concentration in mppcf
22.42
51.70 85.40
100.90
Index for Graphs HI, if 2 #3
1 South Side if2 Band Saw _ Cutting 31ocks - Ventilat;on Cnly Below
n"
II
II if1 If II - Edging
II _
II
11 II
3 =
II
nII tl II - Cutting a Radius
II
II II
#4 z
II
fflII
If If -
II
II
If --
II
If II
Ilia s #2a = H3a r
#4a -
II II II II
II H2 If II - Cutting Blocks -
II #1 II II - Edging
It _
nIt II II - Cutting a Radius _
HhiII If If -
If II _
II It If II
Both Above Eelow
11 II 11 II
II It tl II
It II If II
#5a [forth Side ffl Band Saw Cutting a Radius - Ventilation Both Above Below
A02473
Trial
1 2 3
Table #3 Determination of Percentage Crystalline Free Silica
Present in "Themobestos", "Kaylo" "Carey-Tamp" as Quartz by the "Talvitie" Method
10.
"Thermcbestos" (As Contained in Report 62-IK-l-G-l)
W]_ in Grams
W2 in Grams
W3 in Grams
% Free S3O2
0.5002 0.5000 0.5002
0.0350 0.0347 0.0396
0.0059 0.0068 0.0082
Average Percentage Crystalline Free S1Q2 = 6.4
6.42 5.58 6.28
Trial
1 2 3
"Kaylo" (As Contained in Report 62-IH-l-G-i)
Wj_ in Grams
W2 in Grams
W3 in Grams
| % Free
0.5000 0.5000 0.5000
0.0807 0.0730 0.0553
0 JS nW vt *s* ^4 r, *"* *'*
7.43 1
7.32
1 7,45
Average Percentage Crystall; ~.s Free S^C'2 = 7.4
"Carey-Tamp"
(As Reported by Mr. Thcras M. Durkan) 4 October 1263
Components Soluble in Hcl Other Components Soluble in Phosphoric .-aid
Percentage Crystalline Free Sip2 as Quartz
1C.Si S3.Si
99.5%
00.4%
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Table 04 Ventilation Rates on Two Band Saws
11.
Date
Hood Being Band Saw Checked
Description of Condition
Ventilation Rate in fpm
25 Feb 63 6 Mar 63 25 Feb 63 6 tor 63 25 Feb 63 6 Mar 63
25 Feb 63 Mar 6 3
25 Feb 63 6 Mar 63
02 02
n n
02 02
02 02 02 02
Downdraft
tf It ft If If
Overhead
It fl If
Only Downdraft System in Ooeraticn
ii ti
ii ii
ti
Downdraft 6 Overhead System in Operation
If
II
fl If
II
Every Hood in the System Coen
uif ~-tr
_ it
ti
ti
Downdraft Overhead System in Coeration
ii ti ii
ii ti
ti
Every Hood in the System Open
II If It ft If II
15C0 1450 1200 1200
950 900
650 j 48 uO 4000
25 Feb 63 6 Mar 63
25 Feb 63 6 Mar 63
25 Feb 63 6 Mar 63
25 Feb 63 6 Mar 63
25 Feb 63 6 Mar 63
#i 01 01 01 01 01
01 01 01 01
Downdraft
II II II If II
Overhead
II ft tf
Only Downdraft System in Operation
11 II
II II
l
Downdraft Overhead System in Operation
If fl II
It It
t
Every Hood in the System Open
If It ft II H H
Downdraft Overhead System in Operation
tl tl ii
ri ii
it
Every Hoed in the System Open
ft ft tf If II It
2100 1SC0 1500 1150 1100
5503 4500 42CG
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GKAPri NO. 3 DUST EXPOSURES WHILE FABRICATING THERMOBESTOS & CAREY-TEMP INSULATIC
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