OFFICE OF ENFORCEMENT
EPA-330/2-77-017;
Survey of Vinyl Chloride Levels
in the Vicinity of
r
Keysor-Century, Saugus, California
NATIONAL ENFORCE
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Environmental Protection Agency
Office of Enforcement
EPA-330/2-7?-017a
SURVEY OF VINYL CHLORIDE LEVELS
IN THE VICINITY OF
KEYSOR-CENTURY, SAUGUS, CALIFORNIA
March 1978
National Enforcement Investigations Center - Denver
Region IX - San Francisco
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CONTENTS
I. INTRODUCTION 1
II. SUMMARY AND CONCLUSIONS 4
First NEIC Study 4
Second NEIC Study 5
Keysor-Century and CARB Results 5
Third NEIC Study 5
III. FIELD STUDIES 8
First NEIC Study 8
Composite Sampling 8
Grab Sampling 11
Continuous Monitoring 14
Second NEIC Study 14
Composite Sampling . . . ". 14
Grab Sampling • 15
Keysor-Century Monitoring •-' . 15
CARB Study 15
Third NEIC Study 16
Composite Sampling 16
Grab Sampling 16
IV. FIELD SAMPLING RESULTS AND DISCUSSION 17
First NEIC Study 17
Composite Samples 17
Grab Samples . . . ." 18
Continuous Monitoring 20
Second NEIC "Study 22
Composite Samples 22
Grab Samples 23
Keysor-Century Results 26
CARB Results 26
Third NEIC Study 26
Composite Samples 26
Grab Samples 27
Discussion 27
V. IN-PLANT MONITORING SYSTEM EVALUATION 35
SEQUENTIAL VC MONITORING SYSTEM 35
IN-PLANT MEASUREMENTS 36
EVALUATION OF THE LEAK DETECTION AND
ELIMINATION PROGRAM 43
VCM Monitoring System 44
Leak Definition 44
Plan of Action When a Leak is Detected 45
REFERENCES 46
ii
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APPENDICES
A Process Description
B Methodology and Gas Chromatography/Mass
Spectrometry Confirmation
C 1ST Portable VC Monitor Specifications
and Interference Data
D Medical Assessments
ini
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TABLES
1 Location of Composite Sampling Stations 9
2 Location of Grab Sampling Stations 12
3 Results of Composite Sampling for Vinyl Chloride 17
4 Results of Grab Sampling - Vinyl Chloride
First Study 19
5 Results of Composite Sampling for Vinyl Chloride 23
6 Results of Grab Sampling - Vinyl Chloride
Second Study 24
7 Results of Grab Sampling - Vinyl Chloride
Third Study : 28
8 Percent of Time Concentrations Exceeded
Selected Levels '. . . 34
9 VC Measurements at the Keysor-Century PVC Plant
April 28, 1977 39
FIGURES
1 Composite Sampling Station Locations and
First Study Results 10
2 Grab Sampling Station Locations and
First Study Results 13
3 Miran Recording Showing Infrared Signal
at 10.9 ym 21
4 Grab Sampling Results - Second Study 25
5 Grab Sampling Results - Third Study 29
6 Comparison of VCM Unloading and VCM
Detection by Composite and Grab Sampling 31
7 Location of Monitoring Sites 37
8 Location of Measurements Taken with Portable
1ST Monitor 42
IV
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I. INTRODUCTION
The Keysor-Century Corporation operates a polyvinyl chloride (PVC)
and phonograph record manufacturing facility north of Los Angeles at
Saugus, California. This plant is one of four PVC manufacturers in the
Los Angeles area..It .operates 24 hrs/day, 7 days/week producing PVC from
vinyl chloride monomer (VCM) and vinyl acetate (VA) by suspension
polymerization. A brief process description is included in Appendix A.
Because it produces polymers containing vinyl chloride, a carcinogen,
the facility is subject to requirements of the National Emission Standards
for Hazardous Air Pollutants (NESHAP) under 40 CFR, Chapter I, .Part 61,
Subpart F. This limits VCM in exhaust gas emissions to 10 ppm.-' In
addition, the plant is subject to the Occupational Safety and Health
Administration (OSHA) employee exposure standard (29 CFR 1910.93) of 1
ppm averaged over an 8-hour period, and a maximum of 5 ppm averaged over
any period not exceeding 15 minutes. The action level (level below
which no control action is necessary) under this regulation is 0.5 ppm
averaged over an 8-hour work day.
Engineering-Science, Inc. (ES), under contract to Environmental
Protection Agency (EPA) Region IX, visited the Keysor-Century facility
seven times beginning in late 1976 to conduct a NESHAP inspection. This
included a preliminary visit, two compliance inspection visits, a plant
boundary survey, and three visits to determine the sources of excess
emissions and to recommend accelerated temporary and permanent control
measures. Recommendations included installation of a fume incinerator
to dispose of VCM from major in-plant emission points. As part of their
task, ES reviewed data from the Company's 10-station plant monitoring
system which indicated VCM concentations at times were 1,000 to 5,000
ppm, with frequent concentrations of 100 to 500 ppm.at all monitoring
stations.
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Engineering-Science calculated VCM concentrations 500 ft downwind
from the plant. With a moderate wind (2.5 m/sec or 5 mph) and a 100 ppm
VCM concentration above the plant, a 0.2 ppm concentration was estimated
at steady state conditions. However, at lower wind speeds or higher
plant emissions it was estimated that the downwind concentrations would
be greater with a potential for exceeding OSHA standards.
For the pi ant.boundary survey on March 17, 1977, ES used a portable
VCM gas monitor with a minimum sensitivity of 2 ppm. VCM concentrations
were below instrument detection limits, however wind conditions that day
only permitted sampling upwind of the plant. The hills east of the
plant [Fig. 1, Section III] restrict access to much of the plant boundary.
During the survey the in-plant monitoring system showed levels between
0.3 and 16.5 ppm. -:
ES evaluated the Company's Leak Detection and Elimination Program
(Region IX later rejected the program as inadequate) and questioned
whether the locations of the monitoring sites used in the program were
adequate. In addition, the routine occurrence of high VCM concentrations
indicated the program for controlling leaks was ineffective.
As a result of the earlier ES evaluations and the consideration
that an elementary school is across the road (350 m) from the plant, and
other businesses and residences are also in the immediate vicinity, EPA
Region IX requested that the National Enforcement Investigations Center
(NEIC) immediately conduct a survey of the plant and its environs to (a)
determine ambient levels of vinyl chloride in the area surrounding the
Keysor-Century plant and (b) to assess the adequacy of the monitoring
system as a means of measuring plant vinyl chloride levels and detecting
and eliminating leaks. This first study was conducted April 25-30,
1977.
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During May 1977, Keysor-Century submitted a revised Leak Detection
and Elimination Program, along with data indicating reductions in in-
plant VCM concentrations. (This program was approved by EPA Region IX
on September 27, 1977.)
A second field study was requested by EPA Region IX in early August
to determine whether the VCM levels had varied from the time of the
original survey. Jhis study was conducted August 3-6, 1977.
EPA Region IX requested that the Company install a fume incinerator
because of the continuing high VCM concentrations documented during the
second NEIC field study. This incinerator was installed and operational
about November 24, 1977. Prior to this, on October 1, 1977, the Company
began a round-the-clock composite sampling program which continues to
date. This is discussed later (Section IV).
Following installation of the fume incinerator, the California Air
Resources Board (CARB) collected a series of composite air samples
(October 30-November 8, 1977), in the plant vicinity. EPA Region IX
requested a third study to determine whether this unit had reduced
ambient VCM levels in the. vicinity of the plant. This NEIC study was
conducted November 27-30, 1977, and included concurrent sampling by
CARB.
During the three NEIC studies the plant was operating between 90-
95% capacity.
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II. SUMMARY AND CONCLUSIONS
Field surveys in the vicinity of the Keysor-Century plant
detected vinyl chloride by three procedures: grab sampling,
composite sampling and continuous monitoring.
First NEIC Study - •
During the April 1977 survey, the highest VCM level measured
was 2.7 ppm during a period of approximately 10 minutes (0103-0113)
on the continuously recording Wilks MIRAN* located at the Saugus
Elementary School. Thirty-seven of 240 grab samples (10 minutes)
also showed the presence of VCM, as did two additional grab samples
collected when field crews smelled the characteristic vinyl acetate
odor. The maximum concentration measured by grab sampling was 0.59
ppm at a service station (Station 559) directly west of the plant.
At Station 553, southeast of the facility, one-third of the samples
(8 of 24) showed the presence of VCM with the maximum value 0.40 ppm.
The composite sample's (8 to 18 hrs.) showed VCM present on
8 occasions. The highest level found was 0.75 ppm (9.6 hr. average),
again at the service station (Station 559). In conjunction with grab
samples collected during the composite period, this level would
indicate that peak values at the station may have occasionally exceeded
10 ppm. Although the laboratory procedures used will also detect
EDC and TCE, these compounds were not found in any samples.
A comparison of the Keysor-Century tank car unloading schedule
with all sampling results indicated that VCM was detected by grab
* Brand name.
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and/or composite samples when tank cars were unloaded during
nighttime hours. Thus, atmospheric stability, usually associated
with nighttime hours, and the hills located east of the plant,
acted to minimize dispersion of leaks from the tank cars and other
VCM sources at the plant.
Evaluation of the in-plant monitoring system showed that while
the system was operating satisfactorily, it was only adequate for
monitoring general VCM concentrations in eight plant areas. The
system was not adequate, nor was it installed, to detect leaks from
specific pieces of equipment. In addition, areas such as the collection
pond and the VCM and VA recovery vents nearby are not monitored.
Measurements taken during the evaluation in these and other areas
of the plant exceeded the 10 ppm NESHAP emission limitations.
The high "incipient leak" (background) levels as defined by
Keysor-Century and the periodic VCM emissions >10 ppm could cause
minor leaks to go unnoticed if, in fact, these were important compared
to the higher emissions measured. Also, wind direction and turbu-
lence were shown to transport emissions to monitoring stations in
other locations of the plant away from points of origin. Thus, the
Leak Detection and Elimination Program and the in-plant monitoring
system were ineffective in meeting the purpose for which required,
i.e., detecting and eliminating leaks from equipment in vinyl chloride
service. When overall plant levels are reduced to more acceptable
levels, the monitoring system may be more useful.
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Second NEIC Study
An August 1977 study was conducted during nighttime hours.
Results showed that VCM concentrations from composite samples
were generally higher than during the first survey. The geometric
mean value of grab sample concentrations were about 60% higher than
during the first study (5.2 vs 3.2 ppb). In addition, one 10-mln grab
sample (Station 553, Sequence 2) showed a 6.2 ppn, VCM concentration,
the highest level recorded by this procedure. This tends to verify
data observed by the MIRAN and the earlier assumptions made regarding
composite sample concentrations.
Keysor-Century and CARB Results
Evaluation of 8-hr composite samples collected by Keysor-Century
at three stations around the plant (Stations 501, 503, and 504) indi-
cated a median value of about 20 ppb prior to installation of a fume
incinerator, and below detectable levels afterwards. Data collected
by CARB at the same stations after controls were installed showed a
median value of 45 ppb. Also, two consecutive 2-hr samples CARB
collected at the Saugus School showed levels of 6.2 and 1.8 ppm VCM.
Third NEIC Study
The November 1977 NEIC study included concurrent sampling by
CARB. Grab sampling data again showed a median value of about
5 ppb. Composite samples collected were below NEIC detection
limits (0.08 ppm); however, the more sensitive CARB procedure
also showed a median value of 5 ppb for their 4-hr composites.
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Fume incinerator installation may impact some of the high
VCM concentrations observed earlier, however the median value (5 ppb)
for grab samples has not been reduced nor has the occurrence of
occasional high concentrations in composite samples. This indicates
either the necessity for correcting operation and maintenance procedures
and/or the need for additional control measures.
In the absence of ambient air standards, two possible approaches
are presented for selecting rational ambient VCM levels to protect
the general population in the plant vicinity. One would apply a
safety factor to OSHA levels, the second would adopt a continuous
exposure level consistent with some lifetime carcinogen risk. For
VCM a lifetime risk of 3 x 10"5, consistent with other government
standards, has been estimated at 1 ppb3. The following Table pro-
vides a comparison of various control options with results obtained
during the November survey. The Table indicates that even with a
minimal safety factor, the Company will still exceed allowable
ambient concentrations in the plant vicinity.
PERCENT OF TIME C011CEIITSATIQNS EXCEEDED
SELECTED LEVELS
Safety Factor Control Level
8-hr avg*
15-min max**
Action Level*
1
<0.02
<0.03
<0.1
1/10
2
1
6
1/30
10
4
21
1/100
33 "
13
52
1 PPb
88
20
**Estimated from 15-min NEIC data
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III. FIELD STUDIES
A. FIRST NEIC STUDY - APRIL 25-30. 1977
Three different procedures were employed during the first survey to
determine the impact of plant emissions on air quality in the Saugus
vicinity. Large charcoal tubes were placed at fixed locations and
composited ambient air continuously for approximately 12-hour periods.
Field teams collected grab samples on small charcoal tubes for 10- to
20-minute periods six times daily. A MIRAN* continuous recording
infrared analyzer was installed and recorded vinyl chloride levels at
the Saugus Elementary School during the study period. A review of chain
of custody procedures verified that these were followed on all charcoal
tube samples.
Composite Sampling
Six stations [Table 1 and Figure 1] were established around the
plant to concurrently collect air samples in large charcoal-filled glass
tubes which were fabricated_at the NEIC chemistry laboratories. These
tubes were comprised of three sections, each containing 1.5 g of 14 x 35
NuChar* separated by glass wool and were fused shut before leaving the
laboratory. In the field the fused ends were opened, attached to a
critical orifice and vacuum pump, and an air sample composited for
approximately 12 hours before the tube was replaced. Seven sequential
samples were collected at each station during the study period. An
additional sample was composited over the preceding 18-hr period at the
Saugus Elementary School. At the completion of the sampling period, the
tubes were sealed with fiber tape and cooled with dry ice until analyzed
for VCM, ethylene dichloride, and trichloroethylene at NEIC using
specified laboratory procedures [Appendix B]. Volumetric flow in the
system was checked daily with a 100-ml bubble meter. >low through the
system was controlled at approximately 0.1 liter/nrin.
Trademark
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Table 1
LOCATION OF COMPOSITE SAMPLING STATIONS
Station No. Location
501 East end of north side of Saugus Elementary School,
northwest of Keysor-Century plant and west of San
Fernando Rd.
502 Southwest of sewage treatment plant (STP) 26 at'grit
chamber building, north of Keysor-Century.
503 Southeast corner of Mohawk Service Station due west
of Keysor-Century and west of San Fernando Rd.
504 North end of east side of Railroad Station on south-
east corner of Dayton and San Fernando Road, south of
Keysor-Century plant.
505 North side of Wendell's Machine Products Company
at east end of Drayton Street, south of Keysor-Century
Plant.
506 East side of Paint'n Place on southwest side of
intersection of Magic Mountain Parkway (State 126)
and San Fernando Rd, southwest of Keysor-Century Plant
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10
YSOR-CENTURY
• STATION NUMBER
NUMBER POSITIVE VALUES/MAX. AVG CONC.-ppm
Figure 1. Composite Sampling Station Locations and First Study Results
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11
Grab Sampling
Ten grab sampling stations [Table 2 and Figure 2] were established
around the facility and sampled at 4-hour intervals, six times daily
over a 4-day period. Each day sampling was started one hour earlier.
Thus, at the end of the 4-day period, samples were collected each hour
of the day; i.e., 24 samples collected at each station. Samples were
collected in small, commercially available charcoal-filled glass tubes
specifically designed for organic vapors. The sealed tubes were opened
before use by breaking the end tips, then sealed with plastic caps and
cooled with dry ice when sampling was completed. The samples were
analyzed for vinyl chloride, TCE and EDC at the NEIC laboratories.
Portable, battery-operated pumps were used to draw ambient:air
through the tubes. The small pumps collected about 0.2 liters/min and
the large about 0.8 liters/min. The battery operated pumps provided
greater flexibility in establishing sampling locations since power was
not a requirement.
At the start of every sampling period each pump was calibrated
using a 100-ml bubble meter.' Pumps not operated from car (12-volt)
battery power were frequently recharged to maintain the maximum pumping
capacity.
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12
Table 2
LOCATION OF GRAB SAMPLING STATIONS
Station No. Location
550 West side of bridge on Magic Mountain Parkway 0.2 mi
west of San Fernando Rd. intersection
551 West side of San Fernando Rd 0.4 mi south oT Drayton Rd
552 North side of Railroad Station on southeast corner of
Drayton and San Fernando Rd intersection
553 0.05 mi north of Drayton Rd termination
554 On Springbrook Rd at Keysor-Century Plant gate
555 At entrance to STP No. 26 north of Keysor-Century Plant
556 Dirt road on hill due east of Keysor-Century waste-
water pond
557 East side of San Fernando Rd 0.65 mi north of Drayton Rd
558 East side of Saugus Elementary School
559 East side of Mohawk Service Station west of Keysor-
Century Plant
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13
EYSO^CENTUR
STATION NUMBER
NUMBER POSITIVE VALUES/MAX. CONC.-ppm
Figure 2. Grab Sampling Station Locations and First Study Resultt
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14
Continuous Monitoring
A Wilks Scientific MI RAN Portable Gas Analyzer was installed to
sample the air outside the north side of the Saugus Elementary School.
The instrument is a single-beam, infrared spectrometer with a folded
path gas cell extending to 20 m and a wavelength range selectable from
2.5 to 14.5 urn. Vinyl chloride has absorption peaks at 6.15, 9.8, 10.9
and 13.9 pm with varying sensitivities. Interferences from water vapor
and other organics used at the PVC plant (EDC, TCE, and VA) are present
to varying degrees at these wavelengths. The MIRAN was coupled to a
strip chart recorder which permitted continuous monitoring of vinyl
chloride levels at the school throughout the study. The 10.9 vm wavelength
was used since EDC has no response in this region, while the inter-
ference from vinyl acetate is weak and TCE is medium compared to vinyl
chloride signal levels. The minimum detectable VCM concentration is
slightly less than 1 ppm at this wavelength. Following the field work,
the MIRAN analyzer was returned to NEIC and recalibrated at the instru-
ment settings used. This instrument was not used on the later studies.
B. SECOND NEIC STUDY - -AUGUST 3-6. 1977
The analytical results from the first study were used to plan the
second study. Sampling results showed that only 10 of the 37 positive
determinations occurred during sampling runs starting on the 12-hourly
periods 0700-1800. Of these, five occurred on a single run. This
indicated that meteorological conditions (nighttime inversions) probably
had a significant effect on the VCM levels measured. As a result,
subsequent surveys were limited to nighttime hours.
Composite Sampling
This sampling was conducted using the same collection systems
described earlier. Only five of the original stations were available
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15
since the individual at Station 506 was no longer in business. The
sampling time was divided into two 6-hour periods (beginning at approxi-
mately 1800, 1700, and 1600 on succeeding days) at the remaining stations,
In addition, 12-hour samples were collected during daytime hours at two
stations (Station 503 and 504).
Grab Sampling
All sampling stations and apparatus remained the same as during the
first study. The time between runs was reduced from four to three hours
permitting 13 samples to be collected at each station. Unlike the
initial study where samples were shipped to the laboratory during the
survey, these samples were kept preserved on dry ice during the entire
study period and returned to the NEIC Denver laboratory with the sampling
team.
C. KEYSOR-CENTURY MONITORING - BEGINNING OCTOBER 1. 1977
Keysor-Century established monitoring sites at NEIC Stations 501,
503 and 504 on October 1, 1977. They concurrently collect 8-hr composite
samples in Tedlar* bags'at these stations during each of the three daily
shifts. The Tedlar bags are returned to the Company laboratory for
direct analysis by gas chromatography.
D. CARB STUDY - OCTOBER 30-NOVEMBER 8. 1977
The California Air Resources Board (CARB) study, after installation
of the fume incinerator, entailed collection of a series of 2- and 8-hr
composite samples at the NEIC composite sample Stations 501, 503 and
504. The samplers were designed to collect a composite sample during a
*
Trademark
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16
preset interval by pumping air into a Tedlar bag. At the end of the
compositing interval the sampler automatically begins filling another
bag. When sampling was completed, the Tedlar bags were analyzed at the
CARB laboratory in El Monte, California, by a procedure requiring sample
concentration followed by gas chromatography.
E- THIRD NEIC STUDY - NOVEMBER 27-30. 1977
The third and final study was conducted in cooperation with the
CARB. CARB personnel collected three 4-hr composite samples in Tedlar
bags at three of the same NEIC sample stations used earlier. At the end
of the 12-hour period, the three bags from each station were transported
to the CARB laboratory for immediate analysis. These results were made
available to EPA. Keysor-Century was also routinely collecting 8-hr
samples at these same stations during this period.
Composite Sampling
NEIC samples were collected using the same equipment described
above. The five sampling stations'were the same as used for the second
survey. In hopes of increasing sensitivity to intermittent emissions
(by decreasing dilution volume), the sampling intervals were reduced to
three 4-hour periods during nighttime hours. At Stations 501 and 505
sampling intervals were further reduced to two hours on several occasions,
Grab Sampling
Sampling stations and apparatus remained the same as during the
first two studies. To collect a larger sample volume, collection time
was increased from the 10 minutes used on the earlier studies to 15
minutes.
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17
IV. FIELD SAMPLING RESULTS AND DISCUSSION
A. FIRST NEIC STUDY - RESULTS
Vinyl chloride was measured in the study area by all three methods
-employed. In most cases when VCM was found, it occurred at a number of
stations during a particular sampling sequence rather than at single
stations.
Composite Samples
Forty-three composite samples were collected at the six stations
established around the plant. Eight samples showed the presence of
vinyl chloride concentrations ranging from 0.01 to 0.75 ppm [Table 3].
The detection limits for the charcoal tubes under the sampling condi-
tions were about 0.01 ppm for vinyl chloride and 0.1 ppm for TCE and
EDC. These varied with sampling time (volume). The number of samples
that showed vinyl chloride and the maximum value at each station are
shown in Figure 1. Vinyl chloride was not detected in composite samples
collected at Sewage Treatment Plant No. 26 (Station 502).
Table 3
RESULTS OF COMPOSITE SAMPLING FOR VINYL CHLORIDE
Station/
Sequence
501/0
503/1
504/1
505/1
506/1
503/4
504/4*
503/6
Date
4/25
4/26
4/26
4/26
4/26
4/27
4/27
4/28
Starting
Time
1453
0839
0902
1202
1302
1919
1836
1837
Sampling Time
(min)
1115
683
628
458
448
862
_
936
Concentration
(ppm)
0.11
0.03
0.02
0.02
0.02
0.05
0.01
0.75
Pump failed during sequence. Concentration computed on basis of full
839 min sampling period.
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18
The maximum value found (0.75 ppm at Station 503) was higher than
the OSHA Action Level for occupational exposure. During most of that
sampling period, field teams indicated winds were calm to easterly
before turning southwesterly late in the sampling period. Table 3 shows
that vinyl chloride was observed at four stations on the first sequence
and at two stations on the fourth sequence. However, when the maximum
value was detected only Station 503 showed the presence of vinyl chloride.
EDC and TCE were-not detected in any of the composite samples.
Grab Samples
The grab sampling program entailed collection of 240 samples (24
samples at 10 stations) during a 4-day period. Of these, 37 showed
vinyl chloride in concentrations ranging from 0.02 ppm to 0.59-ppm
[Table 4]. The detection limit for this procedure using the small
sampling pump was about 0.02 ppm for vinyl chloride and 0.2 ppm for EDC
and TCE.
Vinyl chloride was measured at least once at each station. It was
measured 8 times (33% of samples) at Station 553 where the maximum value
was 0.40 ppm. That level was exceeded at Station 556 on the east
overlooking plant property where the maximum of 6 measured values (25%
of samples) was 0.59 ppm. Figure 2 indicates the number of samples
showing VCM and the maximum value at each station.
It should be noted here that the grab sampling procedure is more
sensitive than composite sampling for several reasons. The small tubes
require less solvent in the desorption process resulting in a more
concentrated sample. Also, while the large charcoal tubes may collect a
larger mass than the smaller tube during the sampling period,
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Table 4
RESULTS OF GRAB SAMPLING - VINYL CHLORIDE
FIRST STUDY
Sequence
1
2
3
4
5
6
1 rt
10
IT
1
1 O
12
1 "t
13
1 4
14
i r*
15
16
1 ^
17
18
19
20
21
22
o *•»
23
24
Station Number
s 550 551 552 553
-
0.04 0.02 0.02
0.40
0.02 - 0.02
-
~ « — _
~ — — —
— — — _
— — — —
• » — •
0.23
-
— - - -
0.04
— — — _
0.14
0.38
0.16 - 0.12 0.04
- - - _
-
— - _ _
0.11
554
(ppm)
-
0.20
0.04
— '
-
-
-
-
-
-
-
-
-
-
0.17
0.29
-
-
-
0.08
555
-
-
~
-
-
-
-
-
,
-
-
-
0.09
-
0.06
0.04
0.04
-
-
556
-
-
0.02
-
-
-
0.59
-
-
0.27
-
_
-
-
0.17
-
-
0.08
0.04
557
-
_
0.07
0.02
-
-
-
-
-
-
-
-
_ ,
-
_
-
-
-
-
0.07
558 559
-
_ _
0.40
0.11 0.06
-
-
-
_
-
-
-
-
_ _
-
_ _
0.02
0.13
_
_ _
_
-
Wind Nominal
Direction Starting Time
Calm 4/26
NW
SW
Variable
Calm
SE 4/27
Variable
S
S
SW
NW
Calm 4/28
Calm
NW
S
S
Calm
Calm 4/29
Calm
SW
SW
SE
W
Calm
0700
1100
1500
1900
2300
0300
0600
1000
1400
1800
2200
0200
0500
0900
1300
1700
2100
0100
0400
0800
1200
1600
2000
2400
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20
this will be averaged over a much larger sampling volume (60 vs 2 liters).
Thus, it is possible that when vinyl chloride concentrations are measured
by both samplers at the same location it will only be detected by the
small charcoal tube and not the larger one.
On two occasions 10-minute samples were collected at locations
where a vinyl acetate odor was detected. The first occurred during
sequence 16 when the field team was between Station 555 and 556. This
sample showed a 0.3 ppm vinyl chloride concentration which was later
confirmed by gas chromatography/mass spectrometry (GC/MS) analysis
(Appendix B). A lower value was observed at Station 555 (0.09 ppm) and
none was observed at Station 556 during-that sequence.
On the second occasion, the odor was detected at the railroad
crossing on San Fernando Road (midway between Stations 558 and 559)
leading to STP 26 during sampling sequence 24. The sample yielded a VCM
concentration of 0.06 ppm. Four of the grab sampling stations also
showed measurable concentrations during that sequence [Table 4].
Continuous Monitoring
The continuous monitor was installed at the Saugus Elementary
School on Monday, April 25, and operated through Friday, April 29, 1977.
During that period an infrared signal was detected once, on April 29,
beginning shortly after midnight and extending until about 0130 hr when
the recorder returned to background. The recorder output during this
time period [Figure 3] shows that the maximum level observed was about
2.7 ppm as vinyl chloride.
This concentration, while just within the detection limit of the
large charcoal tubes, was not measured at Station 501 adjacent to the
monitor.
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:
i
l
i
l
i
!
l
i
t
j
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o
o
0
1
i
1
ut
0
'
o
o
0
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o
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o
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o
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OJ
Time
'I
1 •
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o
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IS.
fx
o>
(N
cc.
a
o
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ro
Figure 3. Miran Recording Showing Infrared Sianal at 10.9
um
-------
22
The recording [Figure 3] shows a zero offset of about 5% of full
scale. This was manually set to provide a continuous record of the
MIRAN output even when the instrument showed a measurable amount of
drift throughout the day. This would not affect the results observed.
Other organic interferences released with the vinyl chloride could
have contributed to the signal. Thus, the same signal could have been
recorded by 9.1 ppm VA or 3.5 ppm TCE or combinations thereof. However,
TCE was never detected on any of the charcoal tubes during the survey
period and the sampling team in the area gave no indication of the
characteristic VA odor. (Water vapor and EDC are transparent at this
wavelength). Any contribution to the signal by these other organics
would have reduced VCM concentrations below detectable on the large
charcoal tubes. The grab samples collected during the sampling sequence
(18 which began at 0119 hr on April 29 and extended through 0310 hr)
were positive at three locations [Table 4], Station 553 (collected at
0144), Station 554 (0147) and Station 559 (0212). The sample collected
at the school (0310) was negative for VCM.
B. SECOND STUDY - RESULTS
Only the composite and grab samplers were used for VCM detection on
the second study. Vinyl chloride was detected with both methods.
Composite Samples
Thirty-three composite samples were collected at the five stations
monitored during this study. Of these, 5 were collected during the 12-
hr daytime hours, and the remaining 28 collected during 6-hr nighttime
periods. The results are shown in Table 5. Only one of the daytime
samples was positive. The positive values only appeared at two stations
(503 and 505).
-------
23
Comparison with values obtained during the first study (range 0.01
to 0.75 ppm) indicated that these latter data are substantially higher.
A decrease in instrument sensitivity (2.5 vs 5.0 ug) would account for
loss of the lower more probable values, while shorter sampling intervals
reduced the volume diluting any VCM collected.
Table 5
RESULTS OF. COi'IPOSITE SAtJPLING FOR VINYL CHLORIDE
Station/
Sequence
503/2
503/3
505/7
505/8
Date
8/4
8/4
8/5
8/5
Starting
Time
0132
0652
1633
2200
Sampling Time
(min)
318
716
345
367
Concentration
(ppm)
0.23
0.24
0.32
0.35
Grab Samples
During 13 sampling periods, primarily during nighttime hours, 16
of the 125 samples collected were positive [Table 6]. An examination of
these data indicates one extremely high value (6.2 ppm) at Station 553,
and the general indication of higher values than measured during the
first study. Data comparisons show about the same percentage of positive
values during both studies. However, an instrument sensitivity decrease
during the second study (0.1 vs 0.2 ug VCM) would have eliminated some
of the more probable lower values seen during the earlier study.
As before, when VCM was detected, it was measured at several stations
during a particular sampling sequence. Figure 4 shows the number of
positive samples and the maximum value at each station. Urlike the
earlier study, VCM was not detected at Stations 555, 556 or 559.
-------
Table 6
RESULTS OF GRAB SAMPLING - VINYL CHLORIDE
SECOND STUDY
Sequence
1
2
4
6
7
0
g
10
1 1
1 1
12
13
550
-
0.23
0 12
-
551
0.21
-
0.23
0.21
Station Number
552 553
6.18
.14
0.84
0.51
554 555
(ppm)
0.18
0.24
~ ~
~
" ,
"
~
0.10
556 557
*
* 0.37
*
"" "
•" ™
™ —
~ ~
™ -
0.33
558
-
0.07
-
—
-
-
-
-
0.13
Wind
559 Direction
. - • Variable 8/3
Calm
Calm 8/4
Calm
Calm
SW
Calm
Calm
Calm 8/5
Calm
S
Calm
Calm
Nominal
Starting Time
1800
2200
2400
0300
0600
1700
2000
2300
0200
0500
1600
2100
0100
* Site not accessible
-------
25
STATION NUMBER
NUMBER POSITIVE VALUES/MAX. CONC. -Ppm
Figure 4. Grab Samp/ing Results - Saeond Study
-------
26
C. KEYSOR-CENTURY RESULTS
The Company monitoring program on occasion measured VCM at each
sampling station during every shift. The maximum 8-hr value, 0.4 ppm,
was reported on two occasions. The highest 24-hr average value, 0.16
ppm, determined by averaging three consecutive 8-hr values at a single
station occurred on two occasions, at the same time and location as the
maximum 8-hr values.-
D. CARB RESULTS
The first CARB sampling program yielded a series of 2- and 8-hr
composites at the three sampling sites described earlier. During this
survey two consecutive 2-hr composites collected at the Saugus School
showed 6.2 and 1.8 ppm VCM respectively. The maximum 8-hr average, 2.0
ppm, (calculated from four 2-hr values) occurred during that period, as
did the maximum 24-hr average (calculated from 2-hr or 8-hr composites)
of 0.70 ppm. The second highest 8-hr and 24-hr averages were 0.15 ppm
and 0.11 respectively.
E. THIRD NEIC STUDY - RESULTS
As in the second study, only composite and grab samples were collected,
Samples were collected concurrently by CARB for analyses by their more
sensitive procedure. This methodology was not readily adaptable to
NEIC field studies.
Composite Samples
None of the 46 composite samples showed detectable VCM levels.
With a 5 ug VCM detection limit, the 4-hr samples would only have detected
average concentrations of 0.08 ppm and the 2-hr composites 0.16 ppm.
-------
27
While CARB composites (discussed below) showed measurable VCM concen-
trations, the levels found were below NEIC detection limits.
Grab Samples
As indicated earlier, grab sampling provides a much more sensitive
VCM measurement technique. Thus, while NEIC composite samples did not
detect VCM, 15 grab.samples collected during 15 sampling cycles (150
samples) were positive [Table 7 and Figure 5]. Increasing sampling time
from 10 to 15 minutes increased the analytical sensitivity, allowing
measurement of lower concentrations than found during the second study.
Weather conditions were markedly different from those experienced during
the earlier two studies. Where calm conditions were generally experienced
earlier, northwesterly winds were usual during this sampling period.
This would mean that the VCM transport mechanism to the various sampling
stations probably varied from those considered earlier. This difference
could also account in part for the reduced concentrations at the com-
posite sampling stations.
Three samples contained a sufficient VCM level (>1.2 ug/ml in
carbon disulfide) to permit analysis by GC/MS [Appendix B]. A positive
identification of vinyl chloride was made in samples 553/06, 553/09
(0.41 and 0.29 ppm), and 554/06 (0.69 ppm).
F. DISCUSSION
The discussion following not only includes reference to NEIC data
but also that collected by CARB and Keysor-Century since their results
represent a significant contribution to the data base.
-------
Table 7
RESULTS OF GRAB SAMPLING - VINYL CHLORIDE
THIRD STUDY
Sequence
1
1 n
IU
11
1 O
1C
13
1 Ji
14
15 '
Station Number
550 551 552 553
.. _ _ _
0.05
™" — "™ ™
• — -» _
0.18
0.41
0.16
- - - -
0.29
0.04
0.07 - 0.04
0.07
0.26
554
(ppm)
.
'0.02
i —
—
-
0.69
0.09
-
-
_
_
0.14
555 556
— H
-
- -
-
-
-
0.10
0.16
-
0.09
_ _
- —
557
_
-
-
-
0.06
0.04
-
-
0.09
0.07-
0.07
_
558 559
— —
-
-
-
0.04
-
-
-
-
0.12
0.05
_ _
Wind
Direction
NW
NN
NU
Calm
Calm
NU
NU
NW
NW
MN
NW
NU
NU
NW
NW
Nominal
Starting Time
11/27
11/28
11/29
11/30
1800
2100
2400
0300
0600
1730
2000
2300
0200
0500
1600
1930
2200
0100
0400
CO
-------
29
STATION NUMBER
NUMBER POSITIVE VALUES/MAX. CONC..
ppm
Figure 5. Grab Sampling Results - Third Slu
dy
-------
30
Both the composite and grab sample results from the first NEIC
study indicated that VCM was measurable in the Saugus vicinity a signifi-
cant portion of the time. The grab samples showed that, for short
periods, levels of 0.40 ppm (a maximum of 0.59 ppm was detected) may be
observed close to the plant. In fact, values greater than 0.1 ppm might
be expected 5% of the time. Additionally, low levels (<0.1) could be
detected at 0.8 km (0.5 mi) from the plant (Stations 551 and 557).
The composite samples were generally lower than the grab samples,
except for two results (501/0 and 503/6) of 0.11 and 0.75 ppm for samples
collected over time periods greater than 15 hours. It is unlikely that
the VCM levels maintained these averages.over the sampling period, but
more probable that the levels fluctuated and reached much higher values
for short time periods. In the case of sample 503/6, this would indicate
that levels may easily have reached 10 ppm for short periods when compared
to the four results from the companion grab sample station (559) during
the same period (N.D., 0.02, N.D., 0.13).
When the VCM tank car unloading schedule (liquid only) was compared
to periods when charcoal tubes showed positive results, an interesting
correlation was observed-[Figure 6]. During all nighttime periods that
a tank car was unloading either the grab, composite, or both, sampling
systems showed detectable levels of VCM. However, the fact that several
samples were positive when unloading was not occurring shows that other
sources at the plant also contribute. Figure 6 also gives an indication
that the impact of the unloading is greater during nighttime hours when
atmospheric stability is enhanced either by calm winds and/or ground
level inversions. Thus, grab samples showed VCM present between 0700
and 1700 hr on only one of the four days (April 29) when southerly winds
may have been strong enough to limit vertical mixing.
Because nighttime VCM levels appeared more significant than daytime
levels, the second NEIC study concentrated on that time period. Composite
-------
DATE
-4-23-77
4-26-77
4-2T-77
4-28-77
4-29-77
4-30-77
oooo
c
o
u
c
o
u
c
e
u
c
G
U
C
o
u
c
a
u
if
O6OO
HHI
TIME
12OO
rl
18OO
M
H
I-
-HI IK
24OO
H-k~HH~ MIK -H- -11* HK
C— Composite Sample Containing VCM
3— Oroup Sample Containing V/CM
U- VCM Tank Car Unloading
* — Start o« Sampling Program
J — End of Sampling Program
Figurm 6.'Comparison of VCM Unloading end VCM Defection
by Composite and Grab Sampling
-------
32
samples were in general higher than those measured earlier. The grab
samples also showed higher values. The single highest value (6.2 ppm at
Station 553) verified that these levels were possible in the Saugus
vicinity, could be observed at isolated stations, and may not be measured
by the composite samplers.
A comparison of statistical (log-normal) distributions* of nighttime
grab sample data, from the first two surveys (sampling runs started
between 1800 and 0500) indicated that the geometric mean for the second
survey was almost twice that of the first (5.2 vs 3.2 ppb). Clearly
there was no indication of emission reduction between surveys.
Examination of the Keysor-Century data collected before installation
of the new fume incincerator indicated the 8-hr data had a geometric
mean of about 20 ppb VCM. The 24-hr mean (average of three consecutive
8-hr samples) was similar. The data distribution showed a slight drop-
off from the usual log-normal distribution at low concentrations.
Following installation of the fume incinerator, the Keysor-Century data
were reported as below the instrument detection limits. However, analysis
of CARB data indicated the 8-hr median and 24-hr geometric mean to be
about 45 ppb for the combined data from all stations.
The third NEIC survey, also after installation of the fume incin-
erator, indicated that while extreme values were reduced, the geometric
mean value for the 15-min grab samples were still about 5 ppb VCM. The
4-hr CARB composites collected during the sample study period showed the
same mean value. As indicated earlier, the NEIC composite samples were
all below detectable limits.
NOTE: Generally, ambient air quality data has been found to have a
log-normal probability distribution where the median and geometric
mean value are equal. However, in locations such as this, where only
a single source is present, the distribution may fall off significantly
at lower concentrations. To differentiate these tuo cases, geometric
aa USBd ^ ^ f°meV °aSe> While median Values
-------
33
The data indicate that installation of the fume incinerator has
generally (but not in all cases) reduced the high VCM levels observed in
earlier studies. The excursions measured by CARB data show that even
with controls, significant levels are possible. The source of these
levels whether a result of poor operations, maintenance problems, or
usual procedures, has not been reported. The data also show that 5 ppb
VCM may be the average level expected in the vicinity from the Company's
routine level of operation since this was not reduced by the controls
already installed? '
Ambient standards do not presently exist for exposure of the general
population to VCM and it is not likely that any will be promulgated in
the near future. It has also been observed that disagreement exists
among the medical profession as to levels of concern, as well as factors
of safety that might be applied to existing standards to protect the
health of the general population (see Appendix D).
Two possible approaches were examined as a means of addressing the
safety of those living in the Saugus area. Here consideration must be
given to the fact that this group includes the young, old and infirm
whose health status can be significantly different from that of the
employed and whose exposure may be 24-hr/day for long periods of time.
1 9
One approach having precedent ' is to apply a safety factor to
existing OSHA standards. A factor of 1/10 could be applicable to those
levels in the vicinity (outside the plant) for persons who might be
exposed for an eight-hour period and a factor of 1/30 applicable for
those of the general population in residence in the area (three 8-hour
periods). This technique has been used to regulate radiation levels for
substances which are also considered to be carcinogenic and without a
lower threshold limit. This safety factor would lower the 8-hr average
to 33 ppb (1 ppm = 1,000 ppb 4 30 = 33), the 15-min maximum to 167 ppb,
and the action level to 17 ppb average over an 8-hr period for the
general population exposure. Other factors of safety are also feasible.
-------
34
A second approach would be to select a control level from data used
to establish the NESHAP standard. These data indicated that a continuous
exposure to 1 ppb VCM causes a lifetime carcinogenic risk to the
individual of about 3 x 10"5. This level is in the range of other
government standards for carcinogen risks. It has been suggested that
action be taken whenever the long-term average concentration exceeds
1 ppb.3
Using data collected during the third survey, it is possible to
show the time that established levels would be exceeded for the various
control strategies discussed above (Table 8).
Table 8
PERCENT OF TIME CONCENTRATIONS EXCEEDED
SELECTED LEVELS
Safety Factor Control Level
8-hr avg*
15-min max**
Action Level*
1
<0.02 -
<0.03
<0.1
1/10
2
1
6
1/30
10
4
21
1/100
33
13
52
1 PPb
88
20
**Estimated from 15-min NEIC data
The Table shows that even if a minimal safety factor (1/10) is con-
sidered acceptable, plant emissions presently exceed these limitations;
e.g., the 8-hr average is exceeded 2% of the time. If the 1 ppb control
level is considered, the Company may be required to reduce emissions below
the 10 ppm NESHAP emission limitation to meet this control level in the
plant vicinity.
-------
35
V. IN-PLANT MONITORING SYSTEM EVALUATION
Concurrent with the first air monitoring survey, an inspection was
conducted on April 28, 1977, to assess the adequacy of the gas chroma-
tograph (GC) monitoring system installed by Keysor-Century to measure
plant VC levels and to detect and eliminate VC leaks. To accomplish
this objective, the GC monitoring system and the in-plant monitoring
stations were examined relative to major emission sources. In addi-
tion, VC concentrations were monitored using an 1ST** portable VC
monitor (range 2 to 20 pom) to compare results with the GC monitoring
system and to determine if station relocation is necessary.
Plant operating logs were also obtained to correlate in-plant
VC concentrations with specific process operations.
SEQUENTIAL VC MONITORING SYSTEM
The GC monitoring system collects air samples in nine plant areas:
1. Environmental laboratory
2. Dryer area*
3. Slurry tank area
4. VCM and VA charge pump area (west transfer area)
5. VCM unloading compressor area (tank farm)
6. VCM recovery system area (east transfer area)
7. Monomer work area*
8. West reactor deck*
9. East reactor deck*
ft>
** Trademark
-------
36
Figure 7 shows the sampling port locations relative to the major
areas of the plant. The sample ports for the monitoring stations (MS)
are glass cylinders, 5 cm (2 in) in diameter by 10 cm (4 in) high, con-
taining a bronze bead filter and are connected to the environmental
laboratory by 1 cm (0.375 in) stainless steel lines. Once inside the
laboratory high-density polyethylene lines connect the sample lines to
the analysis system. A 1/8-hp vacuum pump draws the samples through a
16-port selector valve for GC analyses. The monitoring stations are
identified by their location(s) on the selector. The samples are analyzed
with a Hewlett-Packard Model 5834A gas chromatograph with a reported
detectable VCM limit of 50 ppb. Some of the monitoring sites are sampled
twice during a sampling sequence. Typically, each analysis, including
purge time, takes about 3 minutes. Some stations (e.g., MS 5 and MS 6)
are sampled every 48 minutes and other stations (e.g., MS 2/10 and MS
3/11) monitored twice in a sampling sequence, are sampled every 24
minutes. After each analysis the selector valve and sample line leading
to the GC are purged for about 25 seconds with the gas from the next
sample. The air samples from the monitoring stations are exhausted by
the common vacuum pump to a charcoal filter. The GC results are reported
on a continuous monitoring -log maintained by Company personnel.
IN-PLANT MEASUREMENTS
The in-plant measurements for vinyl chloride were made with an 1ST
AG5000 vinyl chloride gas monitor that has a range of 2 to 20 ppm. The
range of this instrument severely limited its usefulness in this case.
Specifications and interference data for the 1ST monitor are given in
Appendix C. Because of possible interference from other hydrocarbons
used in PVC production, the in-plant measurements were compared to the
GC measurements when possible, to confirm the measured in-plant vinyl
chloride concentrations. Additionally, the location of possible sources
-------
37
SOIVENT REGENERATION
AND ST
r
CHEMICAl PIANT, RECORD PRESSING
AND MAINTENANCE SHOP
ENV IAS
I AND I? - AIR IINE
13 - STOS. AIR BAGS
RAILCAR UNLOADING
NOTE - STATIONS 4/16, i, 6 ARE AT
GROUND 1EVE1 (4' ElEV )
STATIONS 2/10, 3/16, 7, 8/14, 9/15
ARE AT SECOND tEVEl (20 ElEV )
Figuru 7. location of Monitoring 5il»t
-------
38
of interference and wind direction were noted when the in-plant measure-
ments were taken to help account for discrepancies. Table 9 compares in-
plant measurements with the GC analyses taken from the continuous
monitoring log of April 28, 1977. Figure 8 shows the location of the
in-plant measurements relative to the GC monitoring stations and major
equipment.
Measurements 1,. 3, 9, 19 and 21 were in plant areas where high
emissions (>10 ppm) are routinely generated and were indicative of unit
operations that routinely occur in the process. Measurement 1 (>20
ppm) was taken about 1.5 m (5 ft) east of the VCM unloading compressor
and next to MS 5. The compressor was pumping VCM vapor from the railcar
to a storage tank at the time of the reading. This compressor has a
pressure relief valve that routinely exhausts VCM vapors while-'in
service. High readings (>10 ppm) were recorded by the GC system and
entered in the continuous monitoring log during the period that VCM
vapors were being transferred. Measurements 3 and 9 did not correlate
with GC readings, however, there were possible interferences from VA
sources noted at the time of these measurements. Measurement 3 (>20
ppm) was taken at the VCM charge pump and measurement 9 (>20 ppm) at the
opening of a slurry tank-. Normally there would be no direct emission
from the VCM charge pump; however, any VCM remaining in the resin slurry
would be emitted from the open vent of the slurry tank. The exact
magnitude of the VCM emissions could not be determined due to the
limited range of the portable monitor and possible interference from VA.
Measurement 19 (>20 ppm) was taken at the wastewater pond area located
about 30 m (100 ft) above the plant. This area is not monitored by the
plant monitoring system. In addition to the pond being a possible
source of VCM, VA, and EDC, the VCM recovery system vent [2.5 cm (1 in)
pipe] and the VA recovery system vent [10 cm (4 in) pipe] terminate at
the edge of the pond.
-------
Table 9
VC MEASUREMENTS AT THE KEYSOR-CENTURy PVC PLANT
April 28, 197?
VC
Concentration (ppm)
Reference
Number on
Plot Plan
1
2
3
4
5
6
Location
1.5 m (5 ft) east of
VC compressor next
to MS 5
4.6 m (15 ft) south
of VC charge pump
in aisle
1 m (3 ft) above VC
charge pump
Next to MS 6
0.6 m (2 ft) above
VC recovery system
pump 1 m (3 ft)
east of MS 6
4.6 m (15 ft) below
experimental 200 gal
1ST Portable
Time Gas Monitor
0915 ' >20
0925 0-5
0935 >20
0940 <1
0942 <2
0945 <1
Keysor-Century
Monitor System
(VC Specific)
5.3 at MS 5
at 0916
1.1 at MS 4
at 0916
1.1 at MS 4
at 0916
1.8 at MS 6
at 1003
1.8 at MS 6
at 1003
1.8" at MS 6
at 1003
Comments
Pumping VC vapor from railcar to VC
storage tank
Possible VA interference
Possible VA interference from VA
charge pump
VC recovery system pump about 1 m
(3 ft) away
reactor 6 m (20 ft)
east of MS 6
Next to MS2/10 dryer
second level
0950
<1
0.4 at MS 2 at
1003
Slurry tanks have opening to
atmosphere
-------
Table 9 (Continued)
Reference
Number on
Plot Plan
8
9
10
11
12
13
14
Location Time
Next to MS 3/11 0955
slurry tanks
second level
At opening of slurry 1000
tank #4 10' west
of MS 3/11
Next to MS 7 VCM 1010
recovery area
second level
Next to 200 gal 1013
experimental
3m (10 ft) north
of MS 7
Next to MS 9/15 1016
reactor area second
level
Along walkway next to 1022
#5 reactor about 8m
(25 ft) from MS 9/15
Along walkway next to 1032
//2 and #3 reactors
VC
Concentration (ppm)
Keysor-Century
1ST Portable Monitor System
Gas Monitor (VC Specific) Comments
<2 0.8 at MS 3
at 1003
>20 0.8 at MS 3 Possible VA interference
<1 0.3 at MS 7
at 1003
<1 0.3 at MS 7 Monomer was being added to
at 1003 reactor
<1 1.2 at MS 9
at 1003
3 1.2 at MS 9 1ST readings ranged from
at 1003 0-15 ppm
<10 0.7 at MS 9 Variable wind during readings
at 1052
about 8m (25 ft)
from flS 9/15
o
-------
Table 9 (Continued)
vc
Concentration (ppm)
Re fc re nee
Number on
Plot Plan
15
16
17
18
Location Time
Between reactor #10 1036
and #7 at MS 8/14
Along walkway next to 1043
reactor #12 12m (40 ft)
east of MS 8/14
Next to reactor #8 1049
1m (3 ft) above VC 1057
rharap numn. next to
1ST Portable
Gas Monitor
5-10
3-7
0-10
3-7
Keysor-Century
Monitor System
(VC Specific) Comments
at MS 8 10.5 ppm
at 1003, 0.8 ppm
at 1052
at MS 8 10.5 ppm
at 1003, 0.8 ppm
at 1052
0.8 at MS 8 Variable wind during readings
at 1052 5-10 mph
0.5 at MS 4
at 1052
MS 4/16
19 Earth berm above plant 1110
to the east about
3m (10 ft) from VC
recovery exhaust
20 At MS 9/15 next to 1332
reactor #7
21 At #4 reactor opening 1345
22 At MS 9/15 after #4 1350
reactor opened
>20
>20
7
8.3 at MS 9 at
1327, 2.6 at MS 6
1.5 at MS 7 at
1327
8.7 at MS 15 at
1348, 26.7 at
MS 6, 14.2 at
MS 7 e*" 1-S48
VA and other HC interference
from pond
Before opening reactor
Reactor opened steam/water
vapor interference
Wind blowing away from MS 9/15
toward MS 7 and MS 6
2."
'ca loa
ar
-------
SOLVENT REGENERATION AND STORAGE
VC COMPRESSOR
O o
TANK
VC-8600
•oo
r c E
ICE
VA-3000
VA-3000
SPARE 3000
00
00
0
4000 CAI REACTORS
2000 CAI REACTORS
0
10
P
II
SlURJtr TANKS
VX)
>•
1-20
O O w
»- oe vi
u tr 3
< 2 o
vu O I
« U
"b
18®
ii i"
. ® X N X \ X-—X
Q'sO O O
RESIN SIlOSi
SAGGING SUO
O
VA
VA
COOI/NG TOWER
2 3 Or
RAflCAR UNLOADING
,®
LOCATION OF 1ST
MEASUREMENTS
LOCATION OF KEVSOH —
CENTURY SAMPLE FORTS
COMPOUND SIlOS
figure 8 location of Measurement* taken with Portable 1ST Monitor
•P-
r\i
-------
43
Measurement 21 (>20 ppm) was taken immediately after the #4 reactor
was opened and before it was filled with water. Any residual VCM and VA
remaining in the reactor could have been vented to the atmosphere when "
it was opened. Measurements 20, 21 and 22 were taken to determine if
the GC monitors at the reactor level (MS 9/15) would be affected by the
opening of the reactor. As indicated in both the 1ST and GC readings,
MS 9/15 was not affected because of the wind direction as noted at the
time of the reading. MS 6 and MS 7 which were downwind at the time
monitored an increase in VCM concentrations. MS 6 is at ground level in
the monomer recovery area and MS 7 is on the second level, indicating
that the wind velocity and direction in the plant directly affects where
and at what concentration VC emissions will be detected. A review of
the continuous monitoring log for the week of April 24, 1977, indicated
that higher concentrations were monitored during the evening and early
morning hours when the air is expected to be more stable.
One objective that could not be accomplished during this survey was
to relate high VC concentrations to specific pieces of equipment. VC
levels often exceeded the limited range of the portable monitor. Other
problems were the slow response time (sometimes as long as 5 minutes) of
the instrument to changing concentrations and, as discussed above,
interference from other hydrocarbons and water vapor.
EVALUATION OF THE LEAK DETECTION AND ELIMINATION PROGRAM
The Leak Detection and Elimination Program as submitted to EPA
Region IX on December 3, 1976, by Keysor-Century Corporation consisted
of three main points:
1'. VCM monitoring system
2. Leak definition
3. Plan of action when a leak is detected
-------
44
VCM Monitoring System
The VCM monitoring system, which is dynamically calibrated twice
daily, appeared to be operating properly at the time of the evaluation.
The readings taken by the portable monitor were comparable with readings
taken by the GC system in cases where no interferences were noted.
Additionally, many instances of high VC concentrations (10 to 214 ppm)
were recorded by J:he GC monitoring system on the day of the inspection.
Although the monitoring system appeared to be operating satisfactorily,
it did not appear adequate for detecting leaks from specific pieces of
equipment. The sampling ports are at least 3 m (10 ft) away from the
equipment in VCM service. Because the plant is in the open, wind
currents alter the areas actually being monitored by a specific sampling
port. As shown by measurements 20 through 22 [Table 9], a reactor
opening was monitored by ports located in the monomer recovery area and
no effect was recorded on ports in the reactor area mainly due to the
wind direction at the time of the opening. Generally speaking, the
sampling ports are located to monitor general VCM levels in nine plant
areas rather than monitoring specific equipment in VCM service.
Leak Definition
Another indication that the monitoring system was only monitoring
general VCM levels was the plant's definition of a leak. As part of the
leak detection program, Keysor-Century defined incipient leak (back-
ground) levels for the nine plant areas based on previously monitored
sample port concentrations. These leak levels range from 45 to 250 ppm
and were to be updated as new equipment was installed and more stringent
controls implemented. These leak levels had to be exceeded before
further action was taken to eliminate the "leak". Based on these levels
-------
45
and process operations that emit high concentrations (>10 ppm) of VCM
on a routine basis, it was apparent that minor leaks, e.g., agitator
seals, piping connections, etc., could go undetected due to the high
VCM background levels in the plant area. It appeared that the
background levels of VCM in the plant should be reduced before changes
(such as adding more stations) are made to the monitoring system.
Once the incipient leak level can be reduced to <10 ppm, a more
effective leak defection system can be instituted.
Plan of Action When a Leak is Detected
The third major part of the program is the action taken to correct
a reported leak. Once a leak is detected, the shift supervisor is
notified and he is responsible for finding and correcting the "leak"
as defined by Keysor-Century. No specific written procedure could be
provided by the plant manager, although the intended procedure called
for a person to use a portable detector to find small leaks and pin-
point the major ones after notification.
The effectiveness of this procedure could not be properly evaluated
since the Company could not provide leak detection or maintenance logs
on how many leaks have been detected and what was done to correct them.
No checklists or written procedures could be provided to indicate that
success of the Leak Detection and Elimination Program is dependent on
how the plant personnel find the leaks and eliminate them. Unless
written procedures are adopted and abatement actions are documented,
the success of the program cannot be evaluated. Because of regular
recording of high VC concentrations by the GC monitoring system, it
can only be presumed that the Leak Detection and Elimination Program
as initiated by Keysor-Century was ineffective at the time of the
inspection.
-------
46
REFERENCES
1. Maximum Permissible Body Burdens and Maximum Permissible
Concentrations of Radionuclides in Air and in Water for
Occupational Exposure, U. S. Department of Commerce,
National Bureau of Standards, Handbook 69, August 1963.
2. Permissible" Dose from External Sources of Ionizing Radiation,
U. S. Department of Commerce, National Bureau of Standards
Handbook 59, 1954.
3. Personal Communication, Roy E. Albert, Chairman CAG, to
R. L. O'Connell, Enforcement Director, EPA Region IX
August 8, 1977.
-------
Appendix A
Process Description
-------
PROCESS DESCRIPTION
The following description and flow diagram [Figure A-l] was obtained
from an ES report to Region IX and from an earlier NEIC visit (May 30,
1974) to the facility.
Briefly described, PVC copolymer is produced from vinly chloride
and vinyl acetate by suspension polymerization in twelve batch reactors:
six 7,500-liter (2,000-gal), and six 15,000-liter (4,000-gal). Two
pilot reactors [750-liter (200-gal) and 47-liter (12.5-gal)] are used to
evaluate new materials. The plant capacity is approximately 55 m. ton
(61 ton)/day.
Additives include a gelatin suspension agent, deconal peroxide
catalyst, sodium bicarbonate buffer, and trichloroethylene (TCE) with
some resins as chain transfer agent. TCE has been found to be carcinogenic.
Reaction times for the small and large batches average 4 to 4.5 hr and 6
to 8 hr, respectively.. Reactors are'usually charged twice each day and
no more than three reactors are brought to a critical state at one time.
Stripping of reactants takes place when the process is about 90% complete.
The excess VCM and VA in the reactors are recovered under pressure and
vacuum respectively, condensed in chilled water cold traps, and recycled.
The reactor batches are directed to any of six open slurry tanks
(approximately 30,000 liters) where the resin is held in suspension
until centrifuged. After 20 to 25 batches, the reactors are cleaned
with ethylene dichloride (EDC) which is recovered and processed for
reuse. EDC is presently being tested for carcinogenicity.
There are two parallel drying systems to accommodate the resin-
water slurry produced, each complete with a centrifuge, flash dryer,
cyclone, screening equipment and baghouses for particulate emission
-------
RECYCLE
TANK FARM RAW
MATERIAL STORAGE
VCM RECOVERY
VINYL ACETATE
RECOVERY
J
REACTORS (12) BATCH
POLYMER PROCESS
SLURRY
TANKS
CENTRIFUGES
FLASH
DRYER
WEIGHING HOPPER
i
F
COMPOUNDING
RESIN
HOLDING
SILO
SALES
SCREENING
T
CYCLONE
RECORD PRESSING
Figure A-l. Keysor - Century Corporation Process Flo
w
-------
control. Dried resin for in-plant use is transferred to holding silos
for temporary storage. From here it is conveyed to the weighing hopper
where it is weighed for compounding and use in record manufacture.
Resin for sale is held in storage silos to await shipment.
-------
Appendix B
Methodology and Gas Chromatograph/Mass
Spectrometry Confirmation
-------
METHODOLOGY
A. Large charcoal tubes. These tubes were shipped to the labo-
ratory in an ice chest cooled by dry ice and'upon arrival were kept in
a freezer until analyzed. The ends of the tubes were sealed with fiber
tape from the time of collection until analysis.
Charcoal from each section of the large tubes was emptied into a
cold 50 ml volumetric flask. Twenty-five ml of cold (6°C) CS0 was added
to each of the flasks to desorb the vinyl chloride. The flasfcs were
placed in a freezer and left for 30 minutes to allow for complete
desorption. An aliquot of each extract was then analyzed on a flame-
lonization gas chromatograph held at the following conditions:
Oven temperature 50°C
Detector temperature 150°C •
Injector temperature 100°C
Column 10- stainless steel,
6% OV-101 on 60/80 GCQ '
The desorption efficiency of vinyl chloride from the large tubes
at a level of 220 Pg on the tube, (each section contained 1.5 g of
NuChar 14 x35) was 100%. Detection limit was 2.5 »g VCM per section.
B. Small charcoal tubes. These tubes were shipped to the labo-
ratory in an ice chest and, upon arrival, were kept in a freezer until
analyzed. The ends of the tubes were closed with plastic caps from the
time of collection until analysis.
The charcoal from the front section (100 mg) of each tube was
S i^i^mLn-0;1? 2 ml,vlal: ,°ne ml of cold (6°C) CS2 was added and
the vial immediately sealed with a septum cap. The viat was then
placed in a freezer for 30 minutes to effect complete desorption An
aliquot of the extract was then analyzed on a flame-ionization gas
chromatograph under the conditions previously given.
The desorption efficiency for vinyl chloride from the small tubes
at a level of 8.5 yg of vinyl chloride on the tube, was found to be 91 x
The data have not been corrected for desorption efficiency.
»un In^baCHk~UPT;:eCt10?S °f charcoal (50 mg) for some of the tubes were
also analyzed. The analysis is done in exactly the same manner as
described above. In no case did the amount of vinyl chloride found on
the back-up section exceed 30% of what was found on the front section
It therefore appears that breakthrough of vinyl chloride was not a
problem in these samples. The amount reported is the sum of the two
sections of the tube. Detection limit was 0.1 ug VCM per section
-------
GAS CHROMATOGRAPH/MASS SPECTROMETRY CONFIRMATION
The following are results from a sample analyzed for vinyl chloride
by combined gas chromatography/mass spectrometry. The sample was a
carbon disulfide extract of an activated charcoal tube sealed in a 2 ml
vial, labeled as follows: Station 560, Hill Northeast of Plant on
Barbed Wire Post, Sequence 16. The routine analysis had indicated a 0 3
ppm VCM concentration. Vinyl chloride was readily identified by
comparing the mass spectrum of the sample to that of a standard vinyl
chloride mass spectrum run on the same instrument. (Figure B-l standard
vinyl chloride and Figure B2-B sample.) There is some solvent interference
at m/e 60 from a component peak that elutes a little earlier than vinyl
chloride (Figure B2-B reconstructed gas chromatogram) but this small
amount of interference did not preclude the positive identification and
confirmation of vinyl chloride in the sample. The interference-was not
laentiliable.
-------
12-3$
VLVft. CHLCHICE STO
a.
13
23 33
ns E
S3 83 73 S3 33
11B 123 133
Figure B-L-Vinyl Chloride Standard
-------
Nl>£€3 25 - IS
10 23
J.lll IJHM
S3 *H3
£•*"-
a.
SD.
"•r1'"",1'^"11!*
13 S3 33 ^3 £3
'3
A. ReconsfrucUd C/J rom at agram
B. Sample
Figure B-2. Vinyl Chloride Sample
-------
Appendix C
1ST Portable VC Monitor
Specifications and Interference Data
-------
.VINYL CKLORi'DE
CONCENTRATION
RANGES
M 40 H
\.l «/,
P»U
1*.
V» "» W
* * » " ?£
»»u
VIHTVOllOniOC
53
AVAILAm.C
lnsTr.u:.tr.fJT
*.0 to 20 ppn range
uoic prepared fcr
Engineering-Science,
1 Inc.
UOOcL AC2C02
l.'.OULL ACuiJ
-.6'.
V-- ;.
r" *"^ . • .
i • *
*». ,'. •*••
*'•.-!
• , i
UOOCL AG-.C03
1ST offers the only Vinyl Chloride sensor w.h.crt
has the ad\^ntcges of the Solid-state Electrou-iic
Cell Sensor". The 1ST Vinyl Chloneis insrru.r.e-: is.
more selective than instruments costing seve'ri-J
times more. (See Interference Dc;a.) Tr-.a'csrr.sir.-
ation of sol.d-stato cncuitry ano sensor rcsu.is m
an Instrument that will provide years of trouole
free operation. •
, INTEnNATICNAL
SENSOR TECHNOLOGY
32O1 TCUTH HALLADZ.Y STPEGT
BANTA ArjA. CALIFCDfMIA
' SPECIFICATIONS:
Scnsor •- SOLIO.S7ATE c<=--=^v
. TIC CELL CAS SENSO=.\ "
Accuracy ±3%.
XUnlmum Ceiecuble
Concentranon 2ppm.nair.
Response Time SO seconds to 80V. of Jmai
reading.
2ero0rifl 3%lnpcr,odoi3montns.
Stability of Calibration ..... Negli3,t)le drift inperloCoJ
6 months.
Recovery Tims ............ SO seconds to 63V..
INTCRFERENCC DATA: .
CarOon Monoxide ......... 100:1
Ammonia ............... 3;i ^
nlor-ne .............. »v 7:mlnus1.>
Denicnc ................ ,~3:1
CofOon Tciracnlodde ..... Jail
Chloroform ............... 30:1
Mclfunol ................ 7;|
Mclhylcnc Chloiide .. ...... 100:1
Tcl'.tciilorocitiylcna ....... 100:1
Accinne ......... . ....... 3;j
.'accr v.ipor 0 IOQZ R.ll.
-------
Appendix 0
Medical Assessments
-------
SfATf OF CMIfORNIA—HEALTH AND WELfARE AGENCY
DEPARTMENT OF HEALTH
2151 BERKELEY WAY
BERKELEY 94704
8*0-7900 Ext. 505
August 3, 1977
B.L. O'Connell, Director
Enforcement Division
United States Enviromaental
Protection Agency,Begion IX
100 California Street
San Francisco, California 9*flll
Re:
Enf:
E-3-2
3-1-5
Dear Mr. O'Connell:
I have read your letter of July 15 concerning the question' of whether
there exists loainent or substantial endangeraent to health of persons
living near the Keysor-Century plant due to vinyl chloride monomer.
All the available data concerning health hazards from vinyl chloride
relate to long-term exposure, and all the unequivocal data to long-term
occupational exposures. 8
While the levels found by the NEIC study of 1977 seem excessively high,
in light of what we know about the long-term hazards, it would not seen
reasonable to use the term "imminent or subetantial endangerraent" of
health status.
For imminent or substantial endangerment to be found it would in my view
be necessary to have long-term exposures (years) to high average or
repeated levels.
There are suggestive data of birth or pregnancy outcome abnormalities
among residents near vinyl chloride plants in Ohio. No exposure data
are known to me, so this type of hazard can hardly be put in quantitative
b'
Your letter enjoined haste, so the information provided above is based on
memory rather than review of scientific reports.
Sincerely,
John S. Goldsmith, N.D.
Medical Epidemiologist
Epidemiological Studies Laboratory
-------
UNITED STATES ENVIRON iv AL
WASHINGTON. D.C. 20460
FROM:
TO:
Or. 807 E. Albert
Chain&an, CAO
R. L. O'Coonell, Region IX
8-556-1408
. OF
RESEARCH AMD OEVU.OPMCN
' B.' L.. O'ConxMll, Director
Enforcement Division, Region IS
Environmental Protection Agency
San Francisco, California 94111
Dear Mr* O'Coonellt
MB 81977
We have reviewed the NXIC nenltorlng report on the vinyl chloride
concentration* near the Keyaor-Century plant in Baugus, California. We
have analysed the aonltoring data in such a way as to take into account
as such as possible the Beaaurements where VC was undetected aa veil as
the concentrationa detected. This was done by assuming chat the neaaure-
asents are distributed as a nornal distribution aa a function of the log
of the dose, fitting the upper portion of the distribution to the measure-
ments that were above the threshold for detection, and extrapolating the
distribution to the 50 percent point, which is the aedlan concentration.
This Dedlaa value is a rough estlaate of the average concentration, and
will of coarse be less than the measured values in this case, since only
37 of the 240 measureoents are above the detection limit.
When this analysis was done, the following nedian values were
obtained.
i
1) All composite saaples combined: 0.33 ppb
2) All grab oample* coebined: 3.2 ppb
3) Grab sfi&plea in night-tine hours: 3.0 ppb
4) Grab samples during daylight hourss 1.9 to 3.0 ppb.
(This diatzibution was not closely log noraal)
Therefore as a conservative (upper part of the range of uncertainty)
osTlaate, the median concentration can be aaeuoed to be 3 ppb, seasured
over a radius of 0.5 vile around tha plane.
-------
-2-
Before the vinyl chloride emission standards vent into effect, the
average concentration over a 3 idle radius of all plants combined was
about 17 ppb, according to the evaluation of Kuztaack and KcGaughy. The
regulations had tic effect of reducing the concentrations to 5 percent
of their unregulated values, or to an average of about 1 ppb.
A continuous exposure to 1 ppb of vinyl chloride causes a life-tice
risk to the individual of about 3slO"5. which is in tie range of other
government standards for carcinogen risks. Therefore it would seem
logical to take action whenever the long-term average concentration
exceeds 1 ppb.
Since the average level appears to be about 3 ppb near the plant,
which Includes the school yard, It would seem logical to take action
sufficient to reduce the ambient concentrations to one third their current
values in order to protect public health.
Sincerely yours,
B. Albert, H.D.
ChadL
Carcinogen Aasesaneat Group (SD-673)
ccs 8^ Gage
W/ Barber
J. Bonine
-------
'MivKitsm or CALIFOH.NIA, IRVINE
MM.KHM • DU.l • ll.MNC • L0> AM-ELES • imhHSlUE • -.AN UIECO • J.AV HUSCISC'0
, SANTA BAIIIIMU • SANTA CRUZ
C\im>RS!\ COl LCf,> or Mhbli.ni
UI.'.WriLM OF lOHMI'UlY \'JD «"IKF. CALIiORNU 927L7
•-NVlKO-.MI-.TvL MI.LUUNt
July 21, 1977
Mr. Charles Eckerman
United States Environmental Protection Agency
Enforcement Division
Region IX
100 California Street
San Francisco, California 94111
RE: E-3-2 ENF-3-1-5
Dear Mr. Eckerman:
The following is in response to Mr. 0' Cornell's letter of July 15, 1977.
You requested that I give you an opinion as to the effect on human health
of exposure to vinyl chloride in the ranges found by the National FiSd Investi
r^ a
75 ppm
' ^
Crasa, °f the ^"-Ctentury Plann augus, 1 or a
Grab samples taken in the community near the plant were reported as havine
concentrations up to 0 50 ppm. A fifteen hour composite average SlS^
5? -, -
ye^^
in both this country and abroad have now sho,vn the ability of vinyl chloridT^r
produce cancer in several species of aninviis "t the exposure l^vel of 50 DP£ A
taken into considerat .or. is information from the ani^H-ork
^
growing out of recent research work is that of Dr. Gehring's group at Dow
StoxmcirYon^f i ^i^, ^ Sr°Ur? h*" been able to s^w^at the normal
^ i cS 2 vinyl chlroide through n«M,gation with hepatic glutathione
may be saturated at high exposure levels M.JS allowing for the formation of
ThUyia^ n e?°Xi?' Jt iS Probabic t'^at the epoxide is the active carcinogen.
The labt piece of information is based on the work that has been done by many
investigators over some long time to the effect that absorption of gases and vapors
by the respiratory route increases with physical activity.
-------
Mr. Charles hckennan
•July 21, 1977
The relationship of these points to the present issue goes something like
this: we are dealing with a well known carcinogen in which the length ol ensure
increases the likelihood of effect. The presence of such a LmJSSd il o?
ien^rl,F^™Cern i^i ^ 2nd yOUng Pe°ple are exP°sed sincetheir po?ential
^ hn rf/^F HTe C° 1 'nUCh g,reater *** that of workers in ^e labor force
-Tw abilitv of the compound to produce tumors in the fetus increases our concern
lor nreynont mothers in the community. The ability of the normal detoxified
whfhU" f llV6r 'H ^ SatUrat£d 1Cdds t0 ^eni for peopled the co^itv
who have diseases which may limit their ability to detoxify vinyl chlorite
L^iTS- tt PUttin§ the?,in.great" risk than healthy workers in the labor force
ab orLd i If f 6SPecialIy in sct001 yard Pounds, may be exposed to greater
became of ?hf * glT atm?sPheric concentration than workers in industry
became of the greater physical activity of children during periods of play.
l ?nUb?K6 ?°ints^rsue v,ery strongly ^r establishrent of exposure limits
6 V?*™ Set by the U'S- DeP^tinent of Labor. The question of
h F K , * '- . e queston o
how far below the industrial TLV is one which can not be set with g?eat precision
The June 1977 report from the National Enforcement Investigation dnSr sights
a^ precedence for a community exposure 1/10 the industrial TLV, the National
Bureau of Standards Handbooks 59 and 69 concerned with Ionizing Radiation Other
tactors for the relation of community exposure levels to industrial TLV?s can
->e ,-ound in standards for carbon monoxide, sulfur dioxide and beryllium
P°llu'j?? Standards for carbon monoxide are 1/3 of the industrial
' 2?,?f ^1 ^^P TLV' ^ Ion8 established community
averaged over a 30 ^ period is
3f the grave consequences of significant exposures to vinyl chloride
ana the potential for its far greater effect on people in the general population
than those in the labor force, the community exposure level of vinyl chloride
should probably be less than 1/10 of the industrial TLV. My recommendation would
be at least 1/50 and more probably 1/100 of the industrial TLV based upon air
sampling that averages concentration over periods of at least 24 hours
In response to your request for a brief statement of my background and
qualifications, please find enclosed a copy of my curriculum vitae.
Sincerely,
B. DwigHt Culver, M.D.
Associate Clinical Professor
enc.
-------
'ENVIRONMENTAL
HEALTH
ASSOCIATES
July 28, 1977
Charles Eckerman
Senior Attorney Advisor
United States Environmental Protection Agency
Region IX
100 California Street
San Francisco, California 91*111
Re: E-3-2
ENF-3-1-5
Dear Mr. Eckerman:
Enclosed is my report and opinion in connection with the EPA
Keysor-Century document.
Please let me know if I can be of additional help to you.
Sincerely yours,
Thomas H. Milty, M.D
THM/kh
End.
?'5C S---ATTUCK AVENUE . BERKELEY CALIFORNIA 94704
-------
ENVIRONMENTAL
HEALTH
ASSOCIATES
S T A T E M E N T
Prepared for the United States Environmental Protection
Agency, in connection with the potential health consequences
posed by vinyl chloride levels measured in the area around
the Keysor-Century Plant at Saugus, California.
Statement of Qualifications.
See attached.
My opinion on the potential health effects of the vinyl
chloride levels reported in the vicinity of the Kevsor-
Century Plant.
I have read the document entitled "Survey of Vinyl
Chloride Levels in the Vicinity of Keysor-Century, Saugus,
California," prepared -fay the U.S. Environmental Protection
Agency Office of Enforcement (EPA-330/2-77-017). My comments
and opinions will be limited to a consideration of the potential
human health consequences of exposure to vinyl chloride air
concentrations approximating those reported in this EPA doc-
ument. I am not qualified to comment on the air sampling
techniques, analytical methodologies, or meteorological consid-
erations discussed in detail in this document. Accordingly,
my opinions are based on the assumption that the reported
levels are substantially representative of the actual levels
present, and that these levels range from about one-half to
-------
STATEMENT Page 2
EPA-330/2-77-011
one parts per million, with at least one reading as high as
2.8 parts per million having been reported. In my opinion
these air concentrations represent a clear and imminent
danger to human health.
The basis for my opinion is as follows. There exists
adequate experimental evidence to confirm that vinyl chloride
is carcinogenic in mice and rats when administered by inhal-
ation at doses as low as 50 parts per million. In man there
is clear, sound scientific evidence to indicate that vinyl
chloride is capable of producing uniformly fatal cancers of
the liver (angiosarcoma), as well as strong evidence implic-
ating the chemical as a cause of cancer of the central nervous
system and possibly the lung. In man the least dose capable
of producing cancer is not known. Based primarily on extrap-
olation from data obtained in studies of experimental animals,
the Occupational Safety and Health Administration (OSHA), at
the advice of scientists from a National Institute for Occu-
pational Safety and Health (NIOSH) established a workplace
permissible exposure level of one part per million vinyl
chloride following extensive administrative hearings in
June of. 1974. In the course of these hearings testimony was
given' to the effect that, based on currently available infor-
mation, no decision could be made concerning risk of exposure
to vinyl chloride at concentrations less than 50 parts per
million. However, testimony to the contrary, that is, a safe
exposvrr -rcr-csr.tration is not possible within the present
-------
STATEMENT
EPA-330/2-77-017
Page 3
state of scientific knowledge, was also given by a number of
scientists from both the public and private sectors. This
latter argument prevailed and, as a result, the one part per
million standard was established.
No national ambient air quality standard for vinyl
chloride exists. In the EPA Keysor-Century report it was
suggested that a factor of one-tenth be applied to OSHA
standards to adapt them to general population exposures. It
is worth while noting here that, historically, it has been a
practice to apply informally a factor of one-tenth the value
of a sound scientifically based workplace exposure limit to
exposures involving the general population. The rationale
here has been that, although the work force is comprised of
comparatively healthy adults, the general population contains
substantial numbers of" infants and children, elderly and
infirm, any or all of whom may be reasonably expected to be
more sensitive to the toxic effects of any chemical agent
than their more healthy employed counterparts. Accordingly,
the argument goes, a safety factor of ten should be applied
to occupationally permissible air concentrations when such
concentrations are applied to the general population as a
whole. Although this tenfold safety factor appears reasonable
when the hazardous substance involved is one that possesses
conventional toxic properties (for example lead, mercury,
strychnine, parathion), when the issue is carcinogenicity,
_.ie argument is substantially weakened. That is, one could
-------
STATEMENT Page 4
EPA-330/2-77-017
argue that exposure of a large number of the members of the
general population could be expected to result in the caus-
ation of a substantial number of cancers even though the
relative risk is extremely low. On the contrary, exposure
to the same carcinogen even at a tenfold higher concentration
would result in few if any cancers because the extremely low
relative risk is unlikely to ever be expressed in a small
(employed) population. The point of" this whole discussion
is that although the tenfold safety factor is reasonable in
connection with conventionally toxic substances, it may not
be reasonable when the toxic substance is a cancer producing
agent. In the latter case a much greater safety factor than
ten would in my opinion be justified.
Thomas H. Milby, M.D.
July 29, 1977
------- |