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K. H. SUTHERLAND. health Office*
HEALTH DEPARTMENT
220 NORTH BROADWAY LOS ANGELES. CALIFORNIA 90012
September 26, 1967
GERALD A. HEIDBREDER. M. D. CHIEF DEPUTY HEALTH OFFICE*
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The California Zonolite Co. 5440 W. San. Fernando Hoad
Los Angeles, California 90039
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Gentlemen:'
Enclosed is a copy of the report of our industrial hygiene study at The California Zonolite Co.
If you have any questions regarding this study, please call 625-3212 extension 474.
Very truly yours.
G. A. H2IDI DER, M.D., H.P.H. 'Health Ofi
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Jilliam V. Cardillo Head Occupational Health Services Acting
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lot OFFICE OF COUNTY HEALTH DEPARTMENT
September 26, 1967
Report of industrial hygiene study at The California Zonolite Co. 5440 W. San Fernando Road Los Angeles, California 90059
Study conducted by:
Division of Occupational Health County of Los Angeles Health Department R. L. Dennerline, Industrial Hygienist . A. Medina, Industrial Hygienist R. Kenen, Industrial Hygienist Air & Industrial Hygiene Laboratory
Department of Public Health State of California
Study requested by: California Department of Industrial Relations Division of Industrial Safety
Summary:
On June 12, 1967 members of the staff of County of Los Angeles Health Department conducted an industrial hygiene study at this plant to evaluate employee exposures to dust containing asbestos, vermiculite, and gypsum. Operations studied included the mixing and bagging of mono-kote, the loading of the furnace with raw vermiculite, and #2 furnace. Non-hazardous levels of asbestos containing dust were detected by the light field method of count ing dust.
General operations and sampling procedure:
A skip loader is used to load the furnace hopper with raw vermiculite, after the furnace hopper is full, the vermiculite is expanded in the furnace and either bagged, bulk loaded or used in the production of mono-kote. Gypsum and asbestos are dumped by hand and mixed together. After mixing, vermiculite is added and the toted mixture is again mixed and bagged and stacked on pallets. The bagging operation is exhausted, but this system is inadequate and does not prevent the escape of the mixed dust and fibers into the atmosphere.
Atmospheric samples of dust were collected in midget impingers, with distilled water as the collecting media. All samples were either taken in the breathing zone of the worker or in the general atmosphere of the plant. The samples were analyzed for dust and fiber particles, using the standard light field technique. Additional samples of air borne mist were collected by a Staplex on filter paper and analyzed for asbestos fiber and free silica.
15171163
The California Zonolite Co
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10l07>s
September 26, 1967
Atmospheric concentration of dust detected:
Sample No.
1.
1
2.
Location
General atmosphere during operation of furnace #2
General, atmosphere loading hopper of furnace
Asbestos
18
9
% Mica,
Biotite & Vermiciilite
TLV in mppcf*
46
i
17 /
75 ' 19..0
Particles of mixed dust detected in mppcf*
3.2
/
5.1 ^
e
3. Breathing zone of
15
operator bagging
mono-kote left side
46
18.5
5.2
4. Breathing zone of
24
operator dripping
gypsum and asbestos
gypsum side
. 64
12.5
3.5
5. Breathing zone of operator dripping
24
gypsum and asbestos
gypsum side
64
12.5
4.0
6. Breathing zone of operator bagging mono-kote, right side
15
46
18.5
5.6'
7. Breathing zone of
24
operator dumping
asbestos and gypsum
asbestos side
64
12.5
3.2
8. General atmosphere in warehouse
9
75
19.0
2.8
9. Breathing zone of operator dumping
24
asbestos and gypsum
asbestos side
Million particles per cubic foot of air Threshold Limit Value
64
12.5
3.8
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15171164
The California Zonolite Co
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10107^3
September 26, 1967
Discussion of results:
The results of the air samplings show that the TLV was not exceeded for the mixture of asbestos fiber and dust. However, at the time of the study it was observed that the existing ventilation system did not appear to be operating in accordance with Los Angeles City Ordinance. Therefore a study will be done to evaluate the existing ventilation system.
RD:ee
Richard Dennerline Industrial Hygienist