ENVIRONIM1AL PROTECTION AGENCY
'Q
AIR QUALITY MONITORING BRANCH
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JUNE. 1978
QOAHiy SURVEY -
CERTAIN-TCD PRODUCTS 'CDRPOPATIffl
, PA
EWIRQNTCTTAL PROTECTION AGENCY - REGION III
» .
SURVEIlMCE & ANALYSIS
AIR QUALITY MONITORING BRANCH
at:
ROBERT IWER
THEODORE ERDMAN
DAVID O'BRIEN
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JUNE, 1978
AIR QUALITY SURVEY -
CERTAIN-TEED PRODUCTS CORPORATION
MOUNTAINTOP, PA
ROBERT KRAMER
THEODORE ERDMAN
DAVID O'BRIEN
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Certain-Teed Products Corporation
Mountaintop, PA
Table of Contents
Abstract
1. Summary
2. Plant Operating Conditions During Testing Periods
2.1 Glass Furnaces
2.2 Forming Lines
2.3 Curing Ovens
3. Site Selection and Location
4. Meteorological Data
5. Sampling Procedures
5.1 Phenol
5.2 Formaldehyde
5.3 Fiberglass
6. Analytical Procedures
6.1 Phenol
6.2 Formaldehyde
6.3 Fiberglass
7. Field Quality Control Procedures
8. Chain of Custody Shipping Procedures
9. Test Results
10. Conclusions
Figures
Figure 1
Figure 2
Plant Process Flow Diagram
Sampling Sites Locations - May 1
Figure 3 Sampling Sites Locations - May 2
Figure 4 Sampling Sites Locations - May 4
Tables
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Plant Production Data
Site Identifications
Meteorological Data - May 1
Meteorological Data - May 3
Meteorological Data - May 4
Test Results
-1-
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Appendices
A Plant Production Data
B Meteorological Data
C Test Procedures
D Operation of Sampling Train - Data Summary
E Description - Hastings Mass Flow Meter
F Rotometer Calibration Data
G Test Results
H Health Effects Data
I Participants in Survey
-2-
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ABSTRACT
At the request of Stephen Jellinek, Assistant Administrator,
Toxic Substances, and in response to citizens inquiries as to the air
quality in tneir neighborhood, an ambient air survey was conducted by
the Environmental Protection Agency, Region III, Philadelphia, PA. The
EPA tests were conducted May 1st, 2nd and 4th, 1978. This survey was
intended to to measure ambient air concentrations of phenols, formaldehyde
and fiberglass particles in the area of the Certain-Teed Products Corpor-
ation, Mountaintop, PA.
The test results for formaldehyde concentrations indicated that the
downwind concentrations ranged from non-detected to 251 parts per bil-
lion (ppb). The time weighted average concentration was 75.2 ppb. The
upwind concentrations ranged from non-detected to 80 ppb. The upwind
time weighted average concentration was 21.9 ppb. The minimum detectable
limit was approximately 5 ppb for formaldehyde.
The test results for phenol concentrations indicated that the downwind
concentrations ranged from non-detected to 21 ppb. The time weighted
average concentration was 5.4 ppb. The upwind concentrations ranged
from less than 1 ppb to 69 ppb. The time weighted average concentration
was 13.6 ppb. The minimum detectable concentration was approximately 1
ppb for phenol.
The EPA test results indicate that the formaldehyde emissions from the
plant may cause eye, nose and throat irritation. Headaches may also be
caused by exposure to formaldehyde at the measured concentrations.
-3-
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1. SUMMARY
At the request of Stephen Jellinek, Assistant Administrator, Office of
Toxic Substances, and in response to citizens inquiries as to the air
quality in their neighborhood, the Air Quality Monitoring Branch of the
Surveillance and Analysis Division, Region III, conducted, with the
support of its Wheeling Field Office, an ambient air study around Certain-
Teed Products Corporation, Mountaintop, PA. The purpose of the study
was to determine whether pollutants were present in the ambient air in
sufficient quantities to present an imminent and substantial endangerment
to public health. The pollutants sampled for included phenols, formalde-
hyde and fiberglass particles. These samples were obtained May 1st, 2nd
and 4th, 1978.
The sampling and analytical procedures for formaldehyde and phenol were
conducted in accordance with the methods documented in "Air Sampling and
Analysis", Intersociety Committee, American Public Health Association,
1972, Method #15C 112 for formaldehyde and Method #ISC 116 for phenol.
The sample collection and analytical procedures for fiberglass are •
contained in the "NIOSH Criteria for a Recommended Standard, Occupational
Exposure to Fibrous Glass", U.S. Department of Health, Education and
Welfare (publication #77-152).
The sampling network consisted of two sampling sites, one upwind and one
downwind from the plant. The upwind sampling site included a meteorological
station which monitored wind speed and direction during the sampling
periods. Every reasonable attempt was made to locate the downwind
sampling sites in an area where the emissions could be seen touching the
ground. The purpose of this was to obtain the maximum possible concen-
trations during the sampling periods.
The weather conditions for the samples obtained May 1st and 2nd were
condusive for this particular sampling network, however, the weather
conditions during May 4th allowed the plum to touch the ground only on
an intermittent basis.
The sampling periods chosen over the three day period included operating
hours from each of the three operating shifts at the plant. A plant
inspection was conducted to assure that the process equipment was not
altered in order to lower the plant emission rates. Production data
obtained during the inspection indicated that both production lines were
operating normally during the three days of the survey.
-4-
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The test results for formaldehyde concentrations indicated that the
downwind concentraitons ranged from non-detected to 251 ppb. The time
weighted average concentration was 75.2 ppb. The upwind concentrations
ranged from non-detected to 80 ppb. The upwind time weighted average
concentration was 21.9 ppb. The minimum detectable limit was approxi-
mately 5 ppb for formaldehyde.
The test results for phenol concentrations indicated that the downwind
concentrations ranged from non-detected to 21 ppb. The time weighted
average concentration was 5.4 ppb. The upwind concentrations ranged
from less than 1 ppb to 69 ppb. The time weighted average concentration
was 13.6 ppb. The minimum detectable concentration was approximately 1
ppb for phenol.
The test results for fiberglass particles indicated that the only fibers
found were naturally occurring fibers, not fiberglass.
The test results indicate that the formaldehyde emissions from the planf
may cause eye, nose and throat irritation. Headaches may also be
caused by exposure to formaldehyde at the measured concentrations.
-5-
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PLANT PkOCEbb I LOW L-IA'-.kAM
FIGURE I
DRY
ESP
• GLASS ; I
LINE M-2 . FURNACE r-ji
PRODJCT
FLO'.^
f
/^^HIGH
I JSTACK
7l
_/
SCRUBBER
UNITS
FORMING
.CHAMBER
CURING OVEN
FOfMING
CHAMBER -I
CURING OVEN
>
tr
..v__
! WET
A
INCINERATOR
I
UNI"
EXISTING AIR POLLUTION CONTROL SYSTEM (MAY 4, 1978) '
AIR POLLUTION SYSTEM-UNDER CONSTRUCTION
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3. SITE SELECTION AND LOCATION
The major objective in selecting the following sites was to simultan-
eously obtain upwind and downwind samples. In the case of the downwind
sites, the sampling trains were moved to the point where the emissions
from the plant could be seen touching the ground.
The weather conditions on May 1st and 2nd were such that the emissions
from the plant could easily be seen as they touched the ground. These
weather conditions remained fairly constant, and therefore, the plume
touch down area from the plant also remained in the same general area.
In addition, this "down wash" from the plant was not interrupted by
periods of light wind speeds.
The light wind speeds and variable wind directions which occurred during
the samples obtained May 4th, caused the plant emissions to touch ground
level only on an intermittent basis.
-12-
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.Table #2
Site Identifications
May 1. 1978
Times at Location
4:49 pm-8:56 pm
Site Code and Identification
1)
2)
3)
4)
Distance and direction from
high stack - 90 ft, SE
Downwind site
Closest residential home -
Wester residence; 79 Church Rd.
(60 ft SW of Site A)
8:56 pm-12:00 midnight
5:15 pm-12:00 midnight
1)
2)
3)
4)
1)
2)
3)
4)
Distance and direction from
high stack -
800 ft. SW of high stack
Downwind site
Closest residential home -
Wester residence; 79 Church Rd.
(200 ft SW of site C)
B
Distance and direction from
the stack - 3000 ft NW of high
stack
Upwind site
Located at Dana Perfume Corp.
-13-
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Table #2
Site Identifications
May 2. 1978
Times at Location Site Code and Identification
9:30am-10:50am 1) A
2) Same location as May 1st, Site A
3) Downwide site
10:50am-2:05pm 1) D
2) Distance and direction from
high stack -
1100 ft. SE of high stack
3) Downwind site
4) Closest residential home -
Wester residence; 79 Church Rd.
(150 ft. NW of site D)
2:10pm-5:00pm 1) E
2) Distance and direction from
high stack - 1300 ft. SE of
high stack
3) Downwind site
4) Closest residential home -
Wester residence; 79 Church Rd.
(350 ft. NW of site E)
5:00pm-6:00pm 1) F
2) Distance and direction from
high stack -
1350 ft. SSE of high stack
3) Downwind site
4) Closest residential home -
Wester residence; 79 Church Rd.
(400 ft. NNW of site F)
-14-
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Table #2, May 2, 1978 - Continued
9:25am-6:00pm 1) B
2) Same location at May 1st,
site B
3) Upwind site
-15-
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Table §2
Site Identifications
May 4. 1978
Times at Location Site Code and Identification
11:45 pm (May 3rd)-5:00 am 1) G
2) Distance and direction from
high stack -
1200 ft SW of high stack
along Church Rd.
3) Downwind site
4) Approximately 1000 ft. SE
of Wester residence;
79 Church Rd.
12:15 am-5:00 am 1) H
2) Distance and direction from
high stack -
2500 ft. NNE of high stack
3) Upwind site
4) Adjacent to Foster-Wheeler
metal fabrication plant
-16-
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4. METEOROLOGICAL DATA
The Climatronics Corp., Model WM-III-540, wind speed and direction
system was used to obtain the meteorological data and was always located
at the upwind sites. The data obtained May 2nd and 4th indicated that
the sampling sites were within ± 20° of the average wind direction at
the downwind sites.
The meteorological data obtained May 1st indicated considerable vari-
ation between the average wind direction and the downwind site locations.
Since all participants in the survey felt certain that the site was
located in the proper downwind position due to the odors and the "high
stack" water droplet downwash that were observed, it is believed that
the discrepency was due to misalignment of the weather vane.
The following data is supplied for each of the three sampling periods,
which are: 5/1/78, from 6:00 pm to midnight
5/2/7By from 10:00 am to 6:00 pm; and
5/4/78, from midnight to 5:00 am
1) Maps showing site locations and average wind direction (WD) (arrow)
2) Summary showing duration of different WD
3) Average wind speeds WS and WD for each hour during the sampling
period and also the overall WS and WD average
4) List of WS and WD (5 minute intervals) during the sampling period
(Appendix B)
5) A copy of the strip chart for the WS and WD for the sampling period
(Appendix B)
-17-
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Table #3
Meteorological Data
May 1, 1978
N=0°/360° S=180° Sample Time:
E=90° W=270° 6:10 pm - midnight
Sample Site B
Average WD = 338°/340<> from all 5 minute readings
WDo Each x = 5 minute time interval Length of time in minutes
310 xx 10
315
320 xx 10
325
330 xxxxxxxxx 45
335 xxxxxx 30
340 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 155
345 xxxxxx 30
350 xxxx 20
355 xx 10
360 xxx 15
Hourly Averages
Time of WS WD
Samples MPH Degrees
6:30-7:00 pm 11 344
7:00-8:00 pm 12 346
8:00-9:00 pm 11 336
9:00-10:00 pm 10 336
10:00-11:00 pm 9 334
11:00-12:00 pm 11 341
-18-
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MlbS LOCATIONS
FIGURE 2
Mav 1. 1978 Sites: A. R & C
Average Wind = 340°
' t'ark, Ar«\i o*
diii Top, P:
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Table #4
Meteorological Data
May 2. 1978
N=0°/360° 5=180° Sample Time:
E=90° W=270° 10:00 am - 6:00 pm
Sample Site B
Average WD = 322° from all 5 minute readings
WD° Each x = 5 minute time interval Length of time in minutes
270 xxx 15
275
280 xx 10
285
290
295
300 xx 10
310 xxxxxxxxxxx 55
315 xx 10
320 xxxxxxxxxxxxxxx 80
325
320 xxxxxxxxxxxxxxxxxxxxxxxxxx 130
335 xx 10
340 xxxxxxxxxxxxxxxxx 85
345 xxx 15
350 xxxxxxxxx 45
355
360 xxxx 20
Hourly Averages
Time of WS WD
Samples MPH Degrees
10:00-11:00 am 10 330
ll:00-noon 11 338
noon-1:00 pm 10 323
1:00-2:00 pm 10 328
2:00-3:00 pm 12 317
3:00-4:00 pm 12 330
4:00-5:00 pm 11 ' 326
5:00-6:00 pm 8 329
Overall average: 11 328
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SAMPLING SITES LOCATIONS
FIGURE 3
May 2, 1978 Sites: A. B. D, E & F
Average Wind = 322°
art
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N=360°
E=90°
WD°
10
20
25
30
40
45
50
55
60
70
80
90
110
120
125
130
140
275
310
330
340
350
360
Table #5
Meteorological Data
May 4, 1978
S=180° Sample Time:
W*270° midnight - 5:00 am
Sample site H
Each x = 5 minute time Interval Length
XXX
XX
X
xxxxxxxx
xxxxxxxxxx
X
XX
XX
XXX
X
X
X
XX
X
X
X
X
X
X
X
XX
xxxx
xxxx
of time in minutes
15
10
5
40
50
5
10
10
15
5
5
5
10
5
5
5
5
5
5
5
10
20
20
Time of
Samples
midnight-1:00 pm
1:00-2:00 pm
2:00-3:00 pm
3:00-4:00 pm
4:00-5:00 pm
Hourly Averages
US
MPH
3
2.5
2
2
2
WD
Degrees
50
71
11
15
38
Overall average:
37
-22-
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SAMPLING SITES LOCATIONS
FIGURE 4
May 4, 1978 Sites: G & H
Average Wind = 35°
.' • 1 Indus i
'
T Park, Area of
Mountain Top, Pa.
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5. SAMPLING PROCEDURES
The sampling and analytical procedures used for formaldehyde and phenol
were in accordance with the methods documented in "Methods for Air
Sampling and Analysis, Intersociety Committee American Public Health
Association, 1972". The specific methods are method #1SC 112 for formal-
dehyde and method #1SC 116 for phenol (see Appendix C). The laboratory
analyses for these samples were conducted by the Wheeling, West Virginia
Field Office of the Environmental Protection Agency, Region III.
The sampling and analytical procedures for fibrous glass are described
in "Criteria for a Recommended Standard - Occuaptional Exposure to
Fibrous Glass", U.S. HEW NIOSH DEW (NIOSH), publication #77-152. The
analyses of these samples were conducted by McCrone Associates, Chicago,
Illinois.
5.1 Phenol Sample Collection Procedure
The sampling train for phenol consisted of one fritted midget
impinger connected to a battery operated personnel sampler pump by
2 feet of 1/4 inch ID latex tubing. The absorbing solution was 15
milliliters of O.ln NaOH.
The sample trains were leak checked before sampling by pulling a 2
inch Hg vacuum and observing a vacuum gauge attached to the impinger
intake. No leak existed if the vacuum remained constant.
Samples were collected for about 2 hours at a flow rate between 550
and 1200 ml/min (see Appendix D - Data Summary of Sampling Pumps).
The flow rates were determined by using a calibrated rotometer
which was an integral part of the sampler.
At the termination of each sampling period, the 15 ml of exposed
absorbing solution was transferred to a O.ln NaOH prerinsed 100 ml
plastic sample bottle. The impinger was rinsed twice with O.ln
NaOH twice and the rinses were transferred to the sample bottle.
Approximately 5 ml of 10% cupric sulfate was added to the sample
bottle to preserve the sample.
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5.2 Formaldehyde Sample Collection Procedure
The sampling train consisted of two fritted midget impingers con-
nected in series with teflon tubing. The impingers were connected
to a battery operated personnel sampling pump by 2 feet of 1/4 inch
ID latex tubing. 15 mis of MBTH (see Appendix C) absorbing reagent
was placed in each impinger.
The sample trains were leak checked before sampling by pulling a 2
inch Hg vacuum and observing a vacuum gauge attached to the impinger
intake. If the vacuum gauge reading remained constant, there were
no leaks in the sampling train.
The samples were collected simultaneous for about 2 hours at a
constant flow rate between 250 and 6540 ml/min (see Appendix D -
Data Summary for Operating of Sampling Pumps). The flow rates were
determined by using a calibrated rotometer which is an integral
part of the pump.
At the termination of each sampling period, the exposed impinger
solutions were transferred to a 100 ml plastic sample bottle which
was prerinsed with MBTH. The impingers were rinsed twice with MBTH
and the rinses were transferred to the sample bottle.
5.3 Fiberglass Sample Collection Procedure
The sampling train consisted of a 37mm 0.8 micron milipore filter
held in the bottom half of a plastic filter holder cassette. The
backing of the cassette was retained in the holder to support the
filter. The filter holder was connected to a battery powered per-
sonnel sampler pump with 2 feet of 1/4 inch ID latex tubing.
Samples were collected for about 2 hours at a flow rate held con-
stant between 2200 and 2900 ml/min (see Appendix D - Data Summary
for Operation of Sampling Pumps). The flow rates were determined
by using a calibrated rotometer which is a integral part of the
sampling pump.
At the termination of each sampling period, the filter holder
cassette was sealed.
-25-
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6. ANALYTICAL PROCEDURE
6.1 Phenol Analyses
The phenolic compounds are trapped by the acid/base reactions of
the acid hydrogen of the phenol group with the NaOH in the impinger
solution, thus forming a sodium salt.
The entire sample was used for one analysis. The 40 to 50 ml of
solution in each sample bottle was diluted to 500 ml. The solution
was acidified with phosphoric acid. 90% of the sample volume was
distilled into a receiver. The distillate was adjusted to PH 10.0
+ 0.2 using an ammonium chloride hydroxide buffer. 4 amino-antipyrine
was added to the distillate which rapidly formed a coupling product
with all phenolic compounds present. The coupling product was
extracted into a small volume of chloroform which was made up to
mark and read at 460 mm in a Spec 20 spectrophometer.
The Wheeling Field Office operates a routine quality control pro-
gram for the phenol analysis which includes external audits (WFO QA
Procedures Manual).
6.2 Formaldehyde Analysis
The formaldehyde initially collected in the sampling solution of
MBTH reacts to form an azine. At the laboratory, the contents of
the sample bottles (40 to 60 ml) were made up to 100 ml with MBTH
absorbing solution. A 10 ml aliquot of the 100 ml samples were
transferred to a receiver. 2 mis of ferric chloride-sulfanic acid
solution was added to the 10 ml aliquot which oxidizes the excess
MBTH in the solution forming a reactive cation. The cation reacted
with the formaldehyde-MBTH azine forming a very stable blue catonic
dye in acid media which was read in a Spec 20 spectrophometer at
628 nm.
7 spiked samples were prepared using exposed absorbing solutions
collected at Mountaintop, PA. These experiments indicated that
excellent recovery can be expected from the analytical procedures
used with the Mountaintop samples. '
3 of these samples were used in a standard addition experiment. The
experiment indicated that there were no interferences present
during analysis of field samples.
-26-
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6.3 Fibrous Glass Analysis
The filter was examined under a visible microscope with the filter
in a medium of identical optical density. Under this condition the
filter is transparent.
Fibrous glass is easily distinguishable from other fibers because,
characteristically, fibrous glass particles are large and more
uniform in shape than naturally occurring fibers.
Fiber counting was performed by traversing the field of the sample
identifying and counting fibrous glass particles as they appear.
The number of traverses is determined by the frequency that fibrous
glass particles are encountered.
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7. FIELD QUALITY CONTROL PROCEDURES
A significant error can be introduced if the rotometers are not cal-
ibrated properly, therefore, the rotometers on the pumps were calibrated
using a Hastings Mass Flow Meter (see Appendix E). The Hastings Mass
Flow Meter was, in turn, calibrated using a bubbler meter which is
traceable to a primary standard.
An increase of 5% in sample volume was made to adjust for differences in
field conditions to standard conditions (25°C, 760 mm barometric pressure),
This correction is based on an average temperature of 10°C during sampling.
No correction was made for differences in barometric pressure because
the Hastings Mass Flow Meter used to calibrate the rotometers is not
sensitive to variations in atmosphereic pressures. The variation of
flow that could be attributed to differences in atmospheric pressure
during sampling was less than 1%. No correction was made for moisture
content of the air because, under worst conditions, the error is less
than 1%.
Calibration data can be found in Appendix F.
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8. CHAIN OF CUSTODY PROCEDURES - SHIPPING
Chain of Custocty Procedures were followed during the sampling program.
The arrival and departure of Individuals at the sampling sites were
noted in the site logs.
The preparation of the sample train and the initiation of sampling were
witnessed and noted in the site logs.
The termination of sampling and removal of the samples were witnessed,
noted in the site log and on the chain of custody cards attached to each
sample.
The samples were sealed with an inspector's seal.
The samples were turned over to the EPA personnel responsible for ship-
ping the samples. This transfer was noted on each chain of custody
card. The EPA personnel responsible for shipping the samples identified
the destination of each sample on the chain of custody card. He also
prepared the samples for shipment, and sealed the shipping containers
with two inspector's seals.
Three sets of phenol and formaldehyde samples were shipped in ice to
EPA, Region III, Wheeling Field Office. The samples were transported by
Allegheny Air Cargo from Wilkes-Barre/Scranton International Airport at
the following times: 12 noon, May 2nd; 6.00 am, May 3rd; and 6:00 am,
May 4th.
The Wheeling Field Office recorded receipt of the sealed shipping con-
tainers (metal coolers) and secured the samples until analysis.
The time between termination of sampling and beginning of analysis for
the phenol and formaldehyde samples was 37 hours for the first set, 17
hours for the second set and 7 hours for the third set.
The fibrous glass samples were shipped in a sealed container to McCrone
Associates. The acknowledgement receipt was returned signed.
-29-
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The assumption is made that the collection and recovery efficiencies of
both methods were 100%. The documentation on the methods support this
assumption. The flow rates, and sampling train designs were consistent
with those prescribed in the methods.
The sensitivity of the fibrous glass method was taken directly from the
method, Appendix C. The sensitivity is 0.2 fibers per ml - 20,000
fibers per M3.
-30-
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9.
TEST RESULTS
The table below gives the concentration found in each sample, the time
weighted average concentration of each sample day, and the time weighted
average for the entire study.
Table #6 - Test Results
Formaldehyde (ppb)
Sample Date:
Run Number
Upwind
Downwi nd
Sample Date:
Run Number
Upwind
Downwi nd
Sample Date:
Run Number
Upwind
Downwi nd
May 1st
1 2 3 avg.
0082
19 25 0 26
Phenol (ppb)
May 1st
1 2 3 avg
2 69 2 25
1 1 21 7
Fibrous Glass
May 1st
1 2 3
- ND ND
ND - ND
May 2nd
1 2 3
- 45 80
151 173 251
May 2nd
1 2 3
29 2 14
2 1 2
May 2nd
1 2 3
ND ND ND
ND ND ND
May 4th
4 avg
- 63
49 151
4 avg
2 13
1 2
4
ND
ND
1 2 avg
29 6 18
41 0 7
May 4th
J 2 avg
1 1 1
708
May 4th
1
ND (ND =
ND
survey
avg
23 _
75 -*
survey
avq
14 4-
5
Non-Detect
The List of Samples and Test Results contained in Appendix G were used
in generating the table shown above.
The sensitivity of the phenol and formaldehyde analyses were dependent
upon analytical sensitivity and the air volume samples.
The minimum detectablilites were:
1. Phenol - 1 ppb
2. Formaldehyde - 5 ppb
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10. CONCLUSIONS
When the EPA test results for phenols are compared to the health effects
data (see Appendix H), it can be seen that no adverse effects at the
measured concentrations can be associated with phenols.
When the measured concentrations of formaldehyde are compared to the
health data (see Appendix H), it is apparent that the formaldehyde
emissions from the plant can cause eye, nose and throat irriration in
sensitive populations. Headaches may also be caused by exposure to
formaldehyde at the measured concentrations.
The installation of the new control equipment, which is expected by
December, 1978, should reduce ambient levels of phenol and formaldehyde
by at least 85%. This will bring ambient phenol concentrations well
below any human response factor, however, even with this expected
effeciencies, ambient concentrations of formaldehyde may still cause eye
irritation and odor responses. The eye irritation threshold (19 ppb)
and odor threshold (50 ppb) of formaldehyde are very low values.
It should be noted that in addition to the control of the phenol and
formaldehyde concentrations, total particulates should be reduced by
95%.
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