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ESCAM0IA PLANT
INTEROFFICE MEMORANDUM
To: Distribution
From: R. W. Wolfe Re: Trip Report to Calvert City -
VCM Monitoring Introduction:
Dote: 14 March 1974
Copies:
/A. K. McMillan
R. E. Jones E. A. Ray W. Wilde D. Francke M. H. Sterman
)
The Air Products and Chemicals, Inc. Plant at Calvert City was visited on 12 March 1974 to compare vinyl chloride analytical procedures and calibration pro cedures used at the Calvert City lab and the Escambia lab.
Summary:
1. Century Organic Vapor Analyses
a) Calibration Gas Standard - The calibration gas of VC1 in the air is prepared differently by the two labs. The calibration gas at Calvert City is prepared in two stages. First, vinyl chloride is added into an evacuated cylinder and then pressured to 400 psig with air. The concentration of vinyl chloride is then determined by a VPC procedure. Secondly, the gas mixture is then metered into a gas mixing valve along with air to give a final gas blend con taining 100-300 ppm vinyl chloride in air. The exact composition is again determined by a VPC procedure.
The calibration gas at the Escambia plant is prepared by adding vinyl chloride to a gas bag and diluting the vinyl chloride with air. The composition of the final gas blend is then determined by a VPC p^cedure identical to the Calvert City procedure.
55svb) Ctfhfury Calibration - The calibration procedure for the Century
Organic Vapor Analyzer is different between the two labs. The Calvert City lab uses a calibration curve which relates vinyl chloride concentration to the Century meter reading. The Escambia lab calibrates the Century meter to read vinyl chloride concentration directly according to the method written in the instruction manual.
2. Residual VCM in Resins
Both the Calvert City method and the Escambia method are identical except for the glassware used to prepare samples for analysis.
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14 March 1974 Trip Report - Calvert City - VCM Monitoring Page 2
Calvert City lab uses a 4 oz, jar and the Escambia lab uses a 30 ml vial. The only concern is the large vapor space present using the 4 oz. jar may result in greater vinyl chloride loss from the tetrahydrofuran solvent.
3. Vinyl Chloride Adsorption - Personnel Monitors
a) The Calvert City adsorption procedure and the Escambia adsorption procedure are basically the same; however, Calvert City lab uses a larger adsorption tube and obtains a greater sample volume o gas. The portable vacuum pumps are charged for 24 hours at Calvert City and only 2 shifts per day are sampled. This allows for a 24-hour recharging period which enables better sample rate control and a longer sampling period.
The Escambia plant initially sampled once each shift which
'
allows only 16-hour recharging period. This results in poorer :`
sample rate control and smaller gas volumes sampled. Charging
was extended to 24 hours on 3/11.
b) The analytical procedures differ only with respect to calculation. The Calvert City procedure uses a calibration curve prepared from weighed standards of vinyl chloride in carbon disuLfide ranging from 0-5 00 ppm.
The Escambia procedure uses an internal standard calculation. The main differences in these two types of calculations are: (1) The use of calibaration curves requires exact repeatability
of the sample injected which is difficult using only 2 uL samples.
Sample size repeatability is not necessary when using the internal standard calculation. (2) The calibration curve procedure may lead to high results due to the adsorption of carbon disulfide by the carbon. Since this type of calculation is based on concentration of-yinyl chloride in the supernatant carbon disulfide solution. The'_assumption is, however, that the concentration of vinyl chloride in the adsorbed carbon disulfide is the same as as in the supernatant carbon disulfide. The internal standard calcula tion eliminates both of these potential problems since the vinyl chloride is determined on a weight basis as compared to the weight of the internal standard.
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Aaxch 19*7 4 > Report - Calvert City - VCM Monitoring
53
fusions:
(.
1. Century Organic Vapor Analyzer
a) The calibration gas blends for the Century organic vapor analyzer as prepared by both labs should be satisfactory. Both methods give a vinyl chloride-air mixture which is ultimately analyzed by same VPC procedure to determine the exact vinyl chloride concen tration.
The use of purchased certified vinyl chloride-air gas standards by both labs will reduce potential inconsistencies between the two labs.'
b) Both the vinyl chloride calibration curve relating vinyl chloride vs Century meter reading and the direct calibration procedure should be satisfactory. The only advantage of the calibration curve would be to show the linearity of the meter.
2. Residual VCM in Resins
The residual monomer analyses should be standardized as to the size of sample preparation bottles used. I feel that the vapor space should be kept at a minimum to minimize monomer losses from the tetrahydrofuran solution.
Vinyl Chloride Adsorption - Personnel Monitoring
The vinyl chloride adsorption test should be standardized as to which analytical procedure is used. The analytical procedure used at Calvert City allows for much faster analyses; however, I feel that it may introduce more errors. The internal standard procedure eliminates any sample volume error and any error associated with the adsorption of carbon disulfide by the carbon.
R. W. Wolfe
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1- .*r i. 2-^\ >,
-41
0. THE WALL STREET JOURNAL, WeJnesday, March 13, 1974
' .... .
' ------ ............. -- 1 - - * ---*>- Vitiyl Chloride Exposure Should Be Cilt
I r-' n't li'i(
ffi^Unmeasurable Levels, Officials Urge
By a Vau. Stkezt JouturAL Staff Reporter plant, which converts vinyl, chloride
WASHINGTON - Over the objection* of polyvinyl chloride, had died from the rare
industry, federal scientists are recommend Uver cancer,
,
ing that worker exposure to vinyl chloride Dr. Key's Institute, an arm of the De
be reduced to amount* too small to be mea partment of Health Education tad Welfare,
sured In order to avert possible liver can make* scientific recommendations on
cer. worker exposure to hazardous substance*
federal standard* currently limit expo However, actual standards are set by 'tbs
sure to vinyl chloride to 600. part* per mil Labor Department's Occupational Safety
lion is Ole atmosphere, end industry expert* and Health Administration, or OflHA.
hove urged that the limit be set at to parts The department hasn't decided whoUwt
per million.
to Issue an emergency standard for Vinyl
However, scientists at the National insti- chloride exposure, an OSHA spokeunut'said
tste for Occupational Safety and Health are yesterday. Dr. Key la proposing "expe
unable "to describe a safe exposure level, dited" procedures to formulate a permanent
Or. Marcus Key. the institute'* director, ad standard. Under such procedures, the de A
vised the Labor Department Therefore, he partment might, for example, skip the usual
added, "We .rejected the concept of a step of appointing an advisory committee to
threshold limit for vinyl chloride gas In the make reoommendatiaas. Expedited stan
atmosphere."
dard setting might take up to four or five
Instead, the institute is recommending month*.
that when an employe is exposed to any Any decision to avoid a more immediate
measurable concentration of vinyl chloride emergency standard would distress labor
gas, he should wear an air-supplied respira groups. The AFL-CIO* industrial union de
tor. partment had sought such e standard. Which
In addition, the proposal calls tor a con would Impose engineering and workplace
trol plan to reduce air-borne levels of vinyl practices to reduce vinyl chtorido^CApoears*
chloride to amounts that can't be detected while a permanent standard la being pre
by certain Recommended procedures, as pared. Without such rules, there lsn '
well fc* an air-sampling ptoced'pe.and. a protection for workers while the
ystetfi of full body protective clothing for making process move* forward,
workers in regulated areas,.-;
don Samuels, the Industrial union
In a memo to the department's Occupa ment's safety andliealUi director.
tion#! ' Safety and Health Administration, "Nothing Is happening in the
Dr. Key said nine cases of angiosarcoma, a Improve protection of workers because .con
rare type of ltver cancer, have been discov cerns are awaiting Issuance of federal stan ered among workers exposed to vinyl chlor dards. Mr. Samuels asserted. Some con
ide for periods of 12 years and longer. Some cerns have asserted they are reducing expo
6,1500 employe* at ST plants operated by 23 sures. and improving procedures without
U.S, manufacturers are potentially In federal directives.-
,,
volved. .. ,T -
?
j--1 -j Dr. Key's treoommepd&Uaa cover*--earn
, The pnmamicame to'pubiic attention in psnles that dfevert vinyl ettkMa, a j-oolor- |J
ffauatr Mban A Aviso* of B. r. Goodrich less gas* totoi polyvinyl. *cbwride, A iwidely
Cfc sdjd ftWworfcersat its Loutevtil^ Ky., u*oi solU plastic material* ^ A V
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