Document LKBxvEGOr9Xngrk3QqXMmVkRw
FILE NAME Manville JMA
DATE 1977 Mar 16
DOC JMA019
DOCUMENT DESCRIPTION Report - Asbestos Exposures During the Cutting and Machining of Asbestos Cement Pipe Prepared for A Pipe
Assoc
ASBESTOS EXPOSURES DURING THE
CUTTING AND MACHINING
;
OF ASBESTOS CEMENT PIPE
Prepared for
The
A Pipe Producers Association
1600 Wilson Boulevard
Suite 1308 Arlington
Arlington Virginia 22209
Prepared by
Wesley M. Noble B.S.
Barbara L. Kawahara M.P.H. W. Clark Cooper M.D.
Equitable Environmental Health
2180 Milvia Street
Berkeley California 94704
Inc.
PRODUCED | JM - 83
March 16 1977
ASBESTOS EXPOSURES DURING THE CUTTING AND MACHINING OF ASBESTOS CEMENT PIPE
March 16 1977
. Equitable Environmental Health Inc. Berkeley California
INTRODUCTION
This is a report on the concentrations of airborne asbestos and total dust produced during typical field cutting and machining operations employed
in the installation of asbestos cement A pipe The study was carried out by Equitable Environmental Health Inc. under a contract from the A Pipe Producers Association and was specifically designed to obtain quantitative information on the potential exposures of workers in the construction trades The information was needed to predict how A pipe
field operations would be affected by alternative health standards for
asbestos in the construction industry
BACKGROUND
Production of asbestos cement pipe began in the United States in
1929. It is used extensively for the transport of water and sewage Current production is estimated at 60 to 65 million linear feet with consumption of approximately 100-140,000 short tons of asbestos per year This accounts for 15 to 20 percent of U.S. asbestos consumption Chrysotile 80 and to a lesser degree crocidolite 20 asbestos are incor-
PRODUCED
JM " 83
porated in the pipe
There are two general categories of C pipe pressure or water pipe
and pressure or sewer pipe made in diameters ranging from 4 to 42 inches The former as the name implies must withstand internal hydrostatic pressures and are tested up to 900 pounds per square inch depending on pressure class rating It usually contains about 17 asbestos pressure pipe is designed to withstand external crush loads and usually contains 10 to 12 asbestos plus 10-15 ground scrap pipe fines The cementitious component
of the pipe is about 60 cement and 40 silica flour which react to reduce
the free lime content below % during the autoclave cure
oe(C_
RELEVANT STANDARDS
In interpreting data in the report it is useful to review recent
current and proposed occupational standards for asbestos It was not until the development of the membrane filter method for direct counting of fibers that occupational standards were based upon fiber concentrations
Prior to that total dust counts were the basis for control In 1968 the
American Conference of Governmental Industrial Hygienists recommended a
weighted average limit of 12 fibers per cubic centimeter based on
fibers greater than 5 micrometers in length and alternatively a 2 million
particles per cubic foot total particle count limit The fiber limit was adopted by the Department of Labor under the Healey Public
Contracts Act in 1969 and was incorporated in OSHA tentative standards
in 1971
A reduced standard was announced by OSHA June 7 1972 to be effected
in two steds
As of July 7 1972 the permissible exposure wa
at
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5 fibers as an hour weighted average TWA with a ceiling of
10 fibers As before only fibers longer than 5 micrometers were
counted As of July 1 1976 the permissible TWA was lowered to 2 fibers
On October 9 1975 OSHA proposed a still more restrictive occupa-
tional standard the new permissible TWA to be 0.5 fibers and the
permissible ceiling concentration to be 5 fibers fibers longer than
5 micrometers This standard was to be applicable only to the manufacturing sector with a separate standard to be promulgated later for the construction
industry
a standard
This been
more stringent standard has not yet been adopted nor has
proposed for the construction industry In the meantime
the National Institute for Occupational Safety and Health NIOSH has
announced its intent to recommend a further reduction of the occupational
standard to a permissible TWA of 0.1 fiber i.e. 100 fibers greater than
5 micrometers per liter of air
STUDY DESIGN
In its request for a proposal the A Pipe Producers Association
requested quantitative exposure to cover both pressure pipe
data on the following and pressure pipe
field
operations
.
1 Machining with a manual field lathe
2 Machining with a driven field lathe
3 Cutting with an abrasive disc
4 Power hole cutting
5 Cutting with chisel using hammer and rasp When possible contractors avoid cutting and machining C pipe in the
field because of the expense The usual procedure is to have appropriate
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sizes cut and machined before being taken to the construction sites Because of this it was not feasible to study all operations at the sites where pipe was being installed Instead it was decided to simulate field
conditions
Arrangements were made to carry out the study on the premises of a
manufacturer of C pipe cutting equipment A workman experienced in the
use of all the tools performed the individual operations with a helper
provided by EEH EEH independently purchased inch diameter sewer pipe
Class 2400 and inch diameter pressure pipe Class 150 from a local
supply house No engineering control or ventilation was utilized since
these are not available in the field approved disposable respirators
were worn by operators and EEH personnel during test periods which produced
high dust concentrations
Each cutting operation when performed in the field is of short
duration compared to an hour workday Consequently the ceiling standard
which covers short time periods of relatively intense exposure would be
more likely to be exceeded than the hour weighted average exposure
standard While the number of minutes defined by the ceiling standard has
not been uniformly defined in regulations a sampling period of 15 minutes
is often used as an effective compromise between catching the peak and
obtaining an adequate sample for analysis
It was determined in advance that a single cutting or machining opera-
tion rarely took as long as 15 minutes For the operations of major interest
the average time per operation was from 3 to 6 minutes It was decided
therefore that several successive operations would be made during each
sampling period The short term sampling period would be approximately 15
PRODUCED minutes unless in the industrial hygienist's judgement a
JM - 83
large sample could be obtained in a shorter period
In order to assess reproducibility three replicate short or
peak breathing zone samples on both the operator and his helper were to be collected for each operation
Simultaneously longer integrated personal samples were to be collected on the operator and helper and area samples at a site located approximately 15 feet away and downwind if there were air movement
These integrated samples were to be collected over periods of 2 or 3
hours each one to span more than one type of field operation Another area sampler was to be used to collect total dust for gravi-
metric analysis This was to be located 5 to 10 feet from the field operation The samples were to be less than one hour in duration to span the three replicate tests for one operation
Background samples of 1 to 2 hours each were to be collected before and after each day's work to ascertain the prevailing ambient asbestos
concentrations
METHODS
Air samples were collected on millimeter diameter 0.8 micron pore
size Millipore cellulose ester membrane filters in accordance with OSHA
and NIOSH recommendations They were all open with the cover of
the filter cassette removed samples Personal sampling pumps were
operated at flow rates ranging from 1.6 to 2 liters per minute The pumps
were calibrated by the soap bubble technique before use Both area and personal breathing samples were taken In the latter the pump
was attached to the worker's belt and the filter clipped to his lapel
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near his face Figure 1 illustrates worker and helper with samplers in place Figure 2 shows the test site with area samplers located near the
operation
All samples were analyzed by LFE Environmental a laboratory accredited
by the American Industrial Hygiene Association following OSHA and NIOSH
.
methods Briefly the analytic procedure consisted of rendering the filter transparent with a high viscosity solution of membrane filter material in a mixture of diethyl oxalate and dimethyl phthalate The asbestos fibers
which lie on the surface of the filter are counted with a phase contrast
microscope at 400x magnification The count area was delineated with a Porton graticule Only fibers exceeding 5 micrometers in length were
counted The laboratory examined 100 microscopic fields or counted 100 fibers whichever came first Fiber identification depended upon a particle
having an aspect ratio of at least 1 and having approximately parallel
sides No attempt was made to identify individual fibers mineralogically in view of the known chrysotile and crocidolite content of the material
under examination No estimate was made of the number of fibers less than
5 micrometers in length nor the number in the electron microscope range
Samples were stored for such studies if they should appear desirablaet
some later time
It should be emphasized that estimates of fiber concentrations below
5 fibers are subject to increasing lack of precision and that those below 0.5 fibers have a fairly wide margin of error often being based
on the observation of relatively few fibers Thus although counts are reported as calculated to two decimal places differences in counts in
these ranges should not be overinterpreted
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STUDY OPERATIONS
Preliminary Survey
On 31 January 1977 Mr. Wesley Noble and Mrs. Barbara Kawahara conducted a preliminary survey to obtain information needed for efficient conduct of the main survey The operation of the field cutting and machining tools was demonstrated Air samplers were taken to determine if a minute sampling period would be adequate
Main Survey
On February 8 and 9 1977 Mr. Noble Mrs. Kawahara and Mr. Ronald LaSalle returned to the plant to perform the main survey Both days were
hazy with the temperature in the 60's and 70's There was virtually no
wind in the morning and only light breezes from the west in the afternoons
The five cutting and machining operations specified under Study Design
were studied plus use of one cutter Wheeler which was introduced for a limited test Descriptions of these operations follow
1 Hand machining with a manual field lathe The lathe Pilot
Ratchet Field Lathe Model 12R was attached to the end of an inch pipe supported 2 to 3 feet from the ground Figures 3 and 4 The lathe had two sets of blades one for the actual cut and the other to machine and profile the end The depth of cut could be adjusted manually with screws A ratchet allowed the operator to turn the lathe by pumping a handle The helper adjusted the depth of cut as the lathe rotated about the pipe and would also aid in turning the lathe For sewer pipe one complete cycle
took about 8 minutes i.e. 2 minutes to cut and 6 to 7 minate minPRODUCED
JM - 83
for set and machining Each short peak sample represented two cycles Cutting pressure pipe took longer 4 minutes for cutting and 8 to 9 minutes for set and profiling Each shortterm sample covered a single cut
Power machining with driven field lathe This electricpowered lathe Pilot Powered Field Lathe Model 12P worked on the same principle as the manual lathe Figures 5 and 6 Due to ease of operation a helper was not really necessary Sewer pipe took 1/2 to 1 minute to cut and 4-1 to 5-1 minutes to profile Two cycles were completed for each short
peak sample Again cutting pressure pipe took longer
1-1 minutes to cut and 5 to 6 minutes to profile two cycles
were used per sample
3 Cutting with abrasive disc This was a gasoline powered abrasive disc saw Stihl with a 10 diameter carbide blade Figure 7 When cutting with the saw the operator held the saw while the helper rolled the pipe along the ground toward or away from him
*
No machining of the ends was performed with this method of cutting On both sewer and pressure pipe one cut could be made in 30 to 45 seconds Each peak sample included four cuts
4 Power hole cutting The tool used for this Pilot Hole Cutter
'
Model 38E is available with either an electric or gasoline
engine The mode used in the test was gasoline powered
Figure 8 It cut a 4-1 diameter hole with a small center plug The cutter was secured to the pipe with a chain The
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JM - 83
engine rotated the blade while the operator continuously adjusted the height of the blade The helper aided in equipment set
It took about 1 minute to cut a hole in sewer pipe and 1-1 to 2 minutes for pressure pipe Two minutes set time was
required between holes Four holes were cut for each peak sample
5 Cutting with hammer chisel and rasp The pipe was cut using a
hammer and chisel and the edges then smoothed with a coarse
file Figures 9 and 10 The helper rotated the pipe as the
operator worked Two cuts of sewer pipe each taking 4 to 6 minutes were made during the short or peak sampling
period Cutting the pressure pipe lasted 11 minutes and only
one cut was made per sample
4
wa
8)
A single test of the Wheeler Chain Cutter Model 2990 was made Although this alternative equipment for cutting pipe in the field was not
included in the original protocol its availability and potential useful-
ness justified a limited trial It has cutting discs mounted on a chain
which is wrapped around pipe Figures 11 and 12 Its action is
controlled hydraulically by an operator who could be as far as 10 to 15 feet
from the pipe being cut Set and cutting required 2 to 3 minutes This
.
was tested once on sewer pipe and once on pressure pipe
Another cutting device manually operated was given a single test
during the preliminary survey This the Pilot Model 4 Pipe Cutter Figure
13 applies a circumferential cutting action from the pressure of rotating
sharpened discs The tool is rotated around the pipe and pressure is
PRODUCED
applied by means of handles The tool can be set up and the cut completed
- 83
in 2 to 3 minutes This was tested only once during the preliminary survey
E
RESULTS
Preliminary Survey
The data obtained during the preliminary survey are summarized in
Table 1. The asbestos concentrations that were recorded indicated that
the air sampling procedures yielded reasonable values for the proposed operations They also showed the comparatively high asbestos dust production during the abrasive disc operation a practice not recommended by the A pipe industry unless workers are provided with NIOSH approved respirators The integrated exposure to the operator during an hour's performance of four representative procedures was 4.3 fibers The
integrated area sample showed 2.9 fibers and 16.8 mg mof total dust
x
Main Survey
The operator's peak exposures to asbestos during each operation
involving sewer pipe and pressure pipe are summarized in Table 2. The conspicuously high concentrations during use of the abrasive disc are
apparent
Table 3 similarly shows the peak exposures of the helper with the
abrasive disc operation again producing high concentrations of airborne|
asbestos
Table 4 summarizes the integrated exposures of the operator and
helper as they performed several operations in sequence Area integrated
samples during the same operations are also shown Background levels
measured at the beginning and
Table 5 presents data on
end of each
total dust
day are included in the table
obtained at a distance of 5 to
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JM - 83
10 feet during each of the cutting and machining operations An
11
unusually high concentration of total dust during the hand lathe operation using sewer pipe was not compatible with the industrial hygienist's impression of total dustiness It was a single determination which cannot be explained
Table 6 provides a general summary of the average exposures of operator
and helper during the operations and integrated exposures during successive
operations both for operator helper and in the area Tables 7A 7B and 7C show the distribution of time for successive
operations which were performed during the collection of the integrated samples
Representative fibers seen in microscopic examinations of the samples are shown in Figures 14 15 16 and 17
DISCUSSION
Background levels As expected the background fiber concentrations
which were recorded in the range of 0.01 to 0.02 fibers are near the limit of sensitivity for the volumes of air and the methods employed in
this study They represent approximate values which indicate very low
concentrations The numbers of fibers found are similar to those found |
by EEH in previous studies
Short term or peak exposures The most notable finding was the
high concentration of airborne asbestos produced by cutting with the
abrasive disc The peak personal samples for the operator and helper
during this operation ranged from two to six times the current OSHA ceiling
standard of 10 fibers and from four to twelve times the proposed
ceiling standard of 5 fibers The helper's exposure was higher
PRODUCED
12
explained by the fact that the rapidly rotating blade of the saw propelled
the dust away from the tool and the operator and often this was directed
toward the helper
None of the other cutting and machining operations produced peak
asbestos fiber concentrations which exceeded the most restrictive currently
proposed ceiling concentration i.e. 5 fiber
A pipe cutter Wheeler not included in the basic protocol was
used for a single operation with sewer pipe and pressure pipe and yielded
peak concentrations well below ceiling levels for both operator and helper
Integrated personal exposures The integrated personal samples
represented the exposures of operator and helper over a period of about
half a work day During the first morning of the study sewer pipe was
cut and machined using all tools except the abrasive disc The operator's
integrated exposure over a period of about three hours was 0.09 fibers
and that of the helper was 0.10 fibers It is obvious that such opera-
tions could be continued through an hour working day without exceeding the
present TWA of 2.0 fibers the proposed TWA of 0.5 fibers or even
the stringent NIOSH recommendation of 0.1 fibers
When essentially similar operations were carried out on pressure pipe
for three hours on the second day the integrated sample for the operator
was 0.75 fibers and that of the helper 0.17 fibers While such
operations continued through an hour work day would comply with the
current standard of 2 fibers modifications in work practices or other
controls would be needed to ensure compliance with a standard requiring
a TWA below 0.5 fibers
When integrated samples were collected covering the periods when
abrasive disc cutting was carried out on sewer and pressure pipe
PRODUCED
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~
PRODUCED -
addition to chisel and rasp use during the same period the high dust
concentrations produced by the abrasive disc led to integrated exposures for a hour period of 3.94 fibers for the operator and 7.07 fibers
for the helper An operator carrying out such work for over 4 hours in an
hour day would exceed the 2 fibers standard one hour of such activity
in a day would exceed the 0.5 fibers proposed standard Similarly the
helper would be in excess of the standard with 2-1 hours of such activity
per day while slightly over half hour of work would cause him to
exceed 0.5 fibers proposed standard All of the foregoing calcula-
tions presuppose zero exposure during the remaining work day It is obvious from the foregoing that without modification ventilation
or engineering control the abrasive disc cutter produces unacceptable
concentrations of airborne asbestos Its use in cutting A pressure or
sewer pipe would appear to be in violation of the current OSHA standard 29 CFR 1910.1001 iii which requires that all operated and
operated tools which may produce or release asbestos fibers in excess
of prescribed exposure limits shall be provided with local exhaust ventila-
tion
Integrated area samples These represented the possible exposure of
a person working about feet from the cutting or machining operation one who might be in a trade different from that of the operator or his
helper The fiber counts were in reasonable agreement with those of the
personal integrated samples During sewer pipe operations they were
extremely low and did not suggest any potential hazard For pressure
pipe operations the three value of 0.44 fibers with no abrasive
disc operations included was below the current TWA of 2 fibers even
if continued for 8 hours It provided little margin of safety for an
PRODUCED
JM -
83
14
0.5 fiber standard however
The area integrated sample during abrasive disc operation 4.90 fibers illustrated again the potential hazard of this operation since workers 15 feet away were subject to concentrations well in excess of the present occupational TWA
Total dust concentrations Estimations were made of the concentrations
of all airborne dust i.e. asbestos + cement + all other particulates during the various operations Because the composition of the dust was not determined in terms of free silica the potential hazard from the
concentrations found cannot be evaluated The present OSHA standard for
total dust even if regarded as inert is 15 mIf it contains crystalline silica quartz the permissible TWA is 30 mdivided by
the % of silica + 2 For example if there were 10 quartz in the dust
the permissible TWA would be 2.5 mReview of Table 5 shows several
operations which produce concentrations of total dust which if long continued would be approaching the silica standard if the airborne quartz
content were sufficiently high Housekeeping needs During the tests it was observed that considerable
amounts of particulate waste and scrap material resulted from the cutting and machining operations Photographs illustrate this well In view of the asbestos content rigorous housekeeping would be necessary with proper storage and disposal of wastes
PRODUCED 4
JM PRODUCED
15
CONCLUSIONS
The use of the abrasive disc saw on A sewer pipe and pressure pipe
produced high concentrations of airborne asbestos fibers The peak con-
centrations in the breathing zone of the saw operator and his helper greatly
exceeded the current OSHA standard for short or peak exposures Use
of this tool without an exhaust ventilation system would appear to be a
violation of current standards When this tool is used for an appreciable
part of the work cycle it can also result in a weighted average TWA
exposure for the work exceeding the current OSHA TWA limit of 2 fibers
The exposures of the operator and helper during field cutting and
machining operations using the manual lathe power lathe hole cutter and
hammer chisel and rasp indicate peak exposures substantially less than
the current OSHA ceiling of 10 fibers and the proposed ceiling of
-
5 fibers Limited tests of the Pilot and the Wheeler cutting tools
indicated that these also produced ceiling concentrations below current
and proposed standards
It is improbable that field personnel would be exposed throughout
a working
day
to
the
intensive
cutting
and
machining
operations
which
were
set up for the purpose of this study It is believed therefore that current
and proposed occupational standards could be met with available equipment
provided that the abrasive disc saw was eliminated or otherwise modified
to reduce dust production to acceptable levels Until such elimination or
modification saw operators and helpers should be required to wear respira-
tors approved by NIOSH for protection against dust
Good housekeeping and proper waste disposal would be an essential part
of industrial hygiene measures needed during the cutting and PRODUCED
A pipe
JM - 83
16
ACKNOWLEDGEMENTS We wish to express our appreciation to Mr. J. R. Rawlins of the Pilot Manufacturing Company of Torrance California who made arrangements for a satisfactory location to carry out the study and also made appropriate tools available and instructed our staff on their use
JM PRODUCED
9
. - B@ -
98
Table 1
Data Obtained in Preliminary Survey of Cutting and Machining Operations on A Sewer Pipe
Operation
Operation Sampled
Abrasive disc
Pilot pipe cutter
Manual lathe Power lathe
Operator integrated Area integrated
Total dust
Vol | Operator Integrated Total |
Sample Duration Sampled
No. Min Liters
Fibers
Air
Fibers ML
3
Air
mq
3
8
14.9
14.7
5
10
18.6
0.086
6
15
27.9
0.12
7
17
31.6
.05
4
57
113
4.3
2
58
109
2.9
101
58
105
16.8
*
A special tool not included in main survey protocol
Note Background sample taken for 49 minutes before pipe cutting began contained 0.017 fibers air . PRODUCED JM PRODUCED - PRODUCEDPRODUCED PRODUCED
PRODUCED
oO
Table 2
Operator's Peak Exposures to Asbestos
Tool used for
Cutting or Machining
Manual lathe
Power lathe
Power hole cutter
Abrasive disc
Chisel and rasp
Wheeler PRODUCED cutt PRODUCED PRODUCED PRODUCED PRODUCED
1
Sample
No
223 223 223
585811
357 357 17
36 38 40
233 233 233
C Sewer Pipe
2
Duration
Min
3 Vol of
Air
Sampled
Liters
11
21.9
11
21.9
9
17.9
13
25.6
14
27.9
14
27.9
15
21.9
15
29.8
14
27.6
454
8.0
454
9.9
454
8.0
14
27.9
11
21.9
9
17.9
,
4
Fibers per ML of Air
0.22 0.14 0.09 av 0.15
0.12
.06 .06
av 0.08
0.51 0.69 0.11 av 0.44
16.7 40.4 49.3 av 35.5
0.23 0.22 0.44 av..30
5
Sample
No.
256 75 76
55 586 586
858 65
68
41 43 45
525
525
525
C Pressure Pipe
6
Duration
Min )
7 Vol of
Air
Sampled Liters
320
24.2
320
22.3
20
37.2
8
Fibers per ML of Air
0.72 0.64 0.17 av 0.51
275
37.2
0.34
275
31.6
0.09
275
27.9
0.57
:
av 0.33
//
33.5
1.47
//
26.0
1.82
18
33.5
1.66
av 1.65
157
13.9
19.8
157
9.9
23.9
157
13.9
17.1
av 20.3
12
23.9
3.71
14
27.9
1.70
10
19.9
0.56
av 1.99
24
14
27.9
.06
70
4
7.4
0.85
Tool used for
Cutting or Machining
Manual lathe
Power lathe
Power hole cutter
Abrasive disc
Chisel and rasp
Wheeler pipe
cutter
PRODUCED JM PRODUCED
PRODUCED
PRODUCED
83 PRODUCED
PRODUCED
PRODUCEDPROUCED
1
Sample
No.
18 21 22
NAO NAO 10
12 14 16
333 333 39
223 28 33
Table 3
Helper's Peak Exposures To Asbestos
A Sewer Pipe
2
Duration
Min
3
Vol of Air
Sampled Liters
220
23.9
220
23.9
220
19.9
4
Fibers per ML of Air
0.13 0.07 0.20 av 0.13
14
27.9
0.06
15
29.8
0.16
16
31.8
0.05
av 0.09
11
21.9
0.29
=
27.9
0.28
13
25.9
7 0.12
av 0.23
455
8.0
58.2
455
9.9
52.6
455
9.9
81.2
av 64.0
14
27.9
0.06
12
23.9
0.13
10
19.9
0.56
av 0.25
5
Sample
No.
73 74 77
384 384 384
260 260 69
246 246 46
48 50 52
A Pressure Pipe
6
Duration
Min )
7
Vol of Air
Sampled
Liters
16
29.0
12
21.7
20
36.2
8
Fibers per ML of Air
0.55 0.07 0.04 av 0.22
18
32.6
0.55
18
32.6
0.39
14
25.3
0.75
. av 0.56
18
32.6
0.29
14
25.3
0.44
19
34.4
0.41
av 0.38
557
9.9
62.0
557
9.9
62.0
557
13.9
55.2
av 59.7
11
21.9
1.37
14
27.9
0.40
11
21.9
0.94
av 0.90
25
13
25.9
0.06
71
+
5
9.0
0.87
4
Tat o)
o
Operations
Asbestos Levels in Operator Helper
Operator Integrated Sample
V^ l
of Fibers
Air
per
Dura- Sam-
ML
Sample tion pled
of
No. Min | Liters Air
and Area Integrated Samples and in
Helper Integrated Sample
_ VOT
of
Fibers
Air
per
Dura- Sam-
ML
Sample tion pled
of
No. Min | Liters Air
Background Samples
Area Integrated Sample
Vol
of
Fibers
Sample
No.
Air Dura- Sam-
tion pled
Min | Liters
per ML of Air
Feb. 8 a.m. Sewer 4 184 366 0.09 3 181 246 0.10 6 184 342 0.04 pipe power lathe
hole cutter
manual lathe
chisel and rasp
Feb. 8 p.m. Sewer 31 pipe chisel and
rasp abrasive disc
112
221
3.94
25
113
154
7.07
32
115
214
4.90
Pressure pipe
abrasive disc
chisel and
rasp
Feb. 9 a.m.
Pressure pipe
54
power lathe
hole cutter
manual lathe
182 248 0.75 99 _ 185 368 0.17 58
194
386
0.44
Background
Feb. 8 a.m.
|
97
Background
53
83
Feb. 8 p.m.
PRODUCED
PRODUCED Background
67
89
Feb. 9 JM
PRODUCED
Background 83
78
=! 130
Feb. 9 83
|
175 0.01 150 0.02 135 0.01 259 0.01
ee)
a)
Ta
Total Dust From Cutting and Machining Operations
1
i
:
Tool used for
Cutting or Machining
Sample
t-
No.
Manual lathe
104
A Sewer Pipe
2
Duration
Min )
3 Vol of
Air
Sampled Liters
37
67.0
Power lathe
102
53
95.9
Power hole cutter
103
42
76.0
Abrasive disc
107
19
34.4
Chisel and rasp
106
39
70.6
4 Total
Dust3
mg )
51.5
5
Sample
No.
113
A Pressure Pipe
6
Duration
Min )
7 Vol of
Air
Sampled
Liters
51
95.9
8
Total
Dust3 mgm)
8.13
5.74
110
57
107
2.99
1.84
111
50
94.0
0.21
37.5
108
13
23.5
34.0
0.1
109
42
76.0
2.89
*
This
single
value
was
much
greater
than
would
have
been
expected
from
the
apparent
dustiness
of
the
operation
-
we have no explanation
JM
-
83 PRODUCED
Oo
Tat
Summary of Data Obtained in Survey of A Pipe Cutting and Machining Operations
Type of A Pipe
Sewer pipe
Tool In
Operation
Power lathe
Hole cutter
Operator's
Exposure Fibers Air
Inte-
Peak | grated
av.08
Helper's Exposure Fibers Air
Inte-
Peak } grated
av.09
av.44 0.09
av.23 0.10
Manual lathe
av
av
Wheeler cutter 0.06
0.06
Chisel and rasp av.30
J
av.25 )
Abrasive disc | av35.5
av64.0 av64.0
Pressure pipe Abrasive disc | av20.3 3.94 av59.7 7.07
Chisel and rasp avl.99
|
av.90
Power lathe | av.33
Hole cutter avl.65
Wheeler cutter
0.85
av.56
t
0.75 av.38
0.17
-ct
0.87
Manual lathe
av.51
|
av.22
Area
Integrated
Fibers
cc Air
0.04
)
4.90
t
0.44
Total Dust
m
mg
5.74 1.84 51.5 29.0 0.1 37.5 34.0 2.89
2.99
0.21 0.1 8.13
9
Background >
Fibers
CC Air 0.1
0.02 0.1
0.1
Fiber
Fiber
concentrations
these
Yests
rasps
are
only
approximate
and
indicate
only
that
the
background
was
extremely
low
JM PRODUCED
JM
-
83PRODUCE
Table 7A
Distribution of Time for Successive Operations During Integrated Samples -February 8 A.M.-
Operator Integrated Sample Helper Integrated Sample Area Integrated Sample
184 minutes
181 minutes 184 minutes
0.09 fibers 0.10 fibers 0.04 fibers
POWER LATHE
sewer pipe
Average of 3 peak samples
*
SET
HOLE CUTTER
SET
sewer pipe
SET
U
Average of 3
a
peak samples
SET
MANUAL LATHE
SET
sewer pipe
SET
U Average of 3
P peak samples
WHEELER
E
CUTTER
sewer
S
pipe
P Single --
Sample
CHISEL &
RASP
sewer
pipe
Single Sample
operator 0.08 cc
helper 0.09 cc
52 min
PRODUCED
JM
-
83 PRODUCED
operator 0.44 cc
helper 0.23 cc
5
42 min
Er
Er
n
operator 0.15 cc
helper 0.13 cc
5
36 min
E
+
n
operator 0.15 cc
operator
0.23
cc
helper
0.13
cc
7-14 min8+
helper
0.06 0.06
cc
14 min
TAL B
Distribution of Time for Successive Operations During Integrated Samples -February 8 P.M.-
Operator Integrated Sample Helper Integrated Sample Area Integrated Sample
112 minutes
113 minutes 115 minutes
0
3.94 fibers 7.07 fibers 4.90 fibers
CHISEL & RASP
sewer pipe
Average of 2 peak samples
ABRASIVE DISC
SET
SET sewer pipe
SET SET
U
--
--
Average of 3 peak samples
ABRASIVE DISC SET
pressure pipe SET
.
SET
U P
Average of 3
peak samples
operator 0.33 cc
helper 0.35 cc
operator 35.5 cc
helper 64.0 cc
operator 20.3 cc helper 59.7 cc
CHISEL & RASP
pressure pipe
Average of 3 peak samples operator 1.99 cc
:
helper 0.90 cc
penn 23 min
r 17 min
7
21 min
4,
38 min
|
E
2
ES i
i
n
C
JM
-
83 PRODUCED
Le]
Table 7C
Distribution of Time for Successive Operations During Integrated Samples
-February 9 A.M.-
Operator Integrated Sample Helper Integrated Sample Area Integrated Sample
182 minutes 185 minutes 194 minutes
0.75 fibers 0.17 fibers 0.44 fibers
POWER LATHE
pressure pipe
Average of 3
peak samples operator 0.33 cc helper 0.56 cc
58 min
JM
83PRODUCE
HOLE CUTTER
SET
pressure pipe
ond
ia
Average of 3
peak samples
operator 1.65 cc
helper 0.38 cc
SW SET
SW
uy E
SET SET
E
Sa L| DC E}; DC
R
CUT EX CUT EX CUT EX CUT EX CUTEX CUT EX
MANUAL LATHE
pressure pipe
Average of 3
peak samples
operator 0.51 cc
helper 0.22 cc single sample
operator 0.85 cc helper 0.87 cc
51 min EC
5 5 9 L~ _ _ 4_9__m.in
ny) E
i i
rs
_ _ _ __3-
a, S-
one
AMEwees
7a
ae
eh
ta
pS
ny mee r Piet eh
ee De
ae
me eb
Coden ales
FIGURE 1. Changing filters on personal samplers
oo
[ a
i
.t
:
7 Fei ns TL Siete? te
teres OS
:
|
: .
,
A he
acme stabendla 9 ele bl
ee OMI VTT es erry A a olen oo)
FIGURE 2 Conducting a typical test Area sampler
;
for fiber concentrations on cart area sampler for
total dust on drum
PRODUCED
JM - 83
nays
spina
Barf peeteess sa a
wr
TaD oc daa
oatteetamee
;
vane EOS get
ect i rd de]
ee|
a
a
IMuHEr
sacl
ee ee ee
FIGURE 4. Operating manual field lathe
ABer
Me mat
ol Wye Ue aes
OVE
Wt des
FIGURE 5 Powered field lathe
FIGURE 6 Operating powered field lathe
DUCED JM
Sees
DUCED
Limit 4trr-ry eo Siaoy
Pc ae
Ste
een uoreaL Ot
a
are
+
ie
PE ee
ae Fee
aekAaictaT
Fe
Gs
SIT
We
atten
Le
FIGURE 7. disc saw
Operating abrasive
eee ice
Se
ee Sey coe
ee
ate
aad Tetva ant SOPts ae pedi rns en nd ina
Sa STs) ay
Fri se
aos e ee |
FIGURE 8. Power hole cutter
2 Fe.
ene ee st
re
J
A
3 rl
ernest B
atl
ny te4 teehee
eg Bian
sth. fae,
ie TTig RAL EF
we
ORIN ei -S,
gt 4
eat
A sed is NS
FIGURE 9. Cutting pipe with hammer and chisel
FIGURE 10. Rasping end of cut pipe
FIGURE 11. Operating Wheeler pipe cutter beginning of cut
FIGURE 12. Operating Wheeler pipe
cutter end of cut
oa)
moe
ey,
et
tans
weooeksiit Bie Ay
eS,
Kio hes
arene,
ole Fiat fect
Se pes
Lee rs rode 4
mE OES
TOL aA
FIGURE 13. Pilot pipe cutter in operation
T
Mba My Pom
0 be
bret Bi
BAeye Y r
Tae,
7. ome
wae
2
Pika
-
Sl
ane
<p
MELE
tve ali} en
ek Ser etl Eye Vane Nyt
D
vetincw
f
PAT ae on
wit
Se
AT
ea ea
A
Bad
.
tert,
@
+ ad
7
an
eee 5
Be dire 2 Ph ie hae oe
FIGURE 14 Chrysotile fiber bundle abrasive disc cutting of pressure pipe
.
'
RRS
St eee erie
hed
FIGURE 15. Chrysotile pressure pipe
fiber
.
power
lathe
PRODUCED
operati
PRODUCED PRODUCED
5
-
a
ane
.
.
teal a4 iid
tt
|
oe
.
e
ee
e
ee
~ *
4
._
~
4
s
.
+
ge .
nn )
wooo ef
.
.
,
4
*
6
Ps
.
a
~~
nr
s
9 ae
.
e .
-
a
.
t N
.
*
.
4
'
FIGURE 16. Chrysotile fiber from area integrated sample
pressure pipe
aX
a 2 3 af
Sat
hes
ae say Wate 4
COA Wank te
Ee' aD
it In if
ry '
FO DeGe oe.
By Ooity ts ee
; }. POPS SONA
a Re, ae
ee
3. Atated
Aas ERS x," Sains on
aD $mxe 4 ss rye
.
a! f. ld
Vig &): +
OT $y" Hg ofa ssAr
9.
* r2
1
PT
Z
a, -~
,
SE oy
sy.Bly es oe J
:
ple
6
>
@. Aaa) ip
tT
sty
Food
FAA.
=)
;
?
ere!
*
a
a
nea oy,
ot, a ne
y- ;
Rh
f
>
A)
;
Te
y P* E
Were ,
FS
ay
3
oe
Fy
voeh) Moy adh Pa a wHte, Uztt REE~~ apyA?e RC H sehen Spela
oe eee eh 1s
A
ow
SUG
Pad
a
ae
Sota
:
ate
:
> . es
TRESS
a ee
ay
ae
ea anes IE tow ode fi
;
sad
.
;
wes
Bot
fi
eo"
Wit
Tee
Sy
GN nd Vy!
we
Tt pee!
.
wm dhe
,
samples PRODUCED FIGURE 17. Field from helper's integrated
types of pipe
JM
DUST EXPOSURES DURING THE CUTTING AND MACHINING OF
ASBESTOS PIPE
ADDITIONAL STUDIES
Prepared for
The A Pipe Producers Association
1600 Wilson Boulevard Suite 1308
Arlington Virginia 22209
Prepared by
1
Equitable Environmental Health Inc.
2020 Milvia Street
Berkeley California 94704
December 15 1977
PRODUCED
JM - 83
INTRODUCTION
On March 16 1977 Equitable Environmental Health Inc. submitted a draft report to the C Pipe Producers Association which provided quantitative data on dust exposures during field operations in which sewer and pressure pipe were subjected to a number of typical field cutting and machining operations A final report on the above was completed in July 1977 and the results have been incorporated in recommendations for work practices in the handling of C pipe
On July 12 1977 the Association requested additional studies of dust exposures involving other field operations These also included a quantitative estimation of potential exposures to quartz
STUDY DESIGN & OPERATIONAL PLAN
Determination of airborne asbestos fiber concentrations Airborne fiber
concentrations were determined during the following operations
1 Unloading pressure pipe at work site
2 Laying pressure pipe in trench 3 Cutting operations
a Cutting with manual saw pressure pipe b Cutting with snap cutting equipment pressure and sewer pipe c Cutting with abrasive disc wet pressure and sewer pipe 4 Machining operations a Cutting and machining with Doty tool pressure and sewer pipe
b Use of tapering tool air duct pipe c Machining differing sizes of pressure pipe 4 8 and 16
with manual lathe
PRODUCED JM - 83
5 Hole cutting
a Use of drill and rasp
6 Tapping operations
pressure and sewer pipe
a Dry tap with Mueller J
pressure and sewer pipe
b Wet tap with Mueller 8-100
pressure and sewer pipe
7 Coupling removal i.e. removing pipe from line
3 Hammer and chisel pressure and sewer pipe
It was not possible to set up a cutting operation with a cooled masonry radial arm saw or to remove pipe from a line with a sabre saw
Determination of quartz Samples of total and respirable dust integrated over a number of operations were collected and analyzed for quartz
METHODS
Each operation when performed in the field is of short duration compared to an hour workday Consequently the OSHA ceiling standard intended to cover short periods of relatively intense exposure would be more likely to be exceeded than would be the hour time weighted average TWA standard A sampling period of 15 minutes is regarded as suitable for determining peak or ceiling exposures while at the same time obtaining an adequate sample for
analysis
Most of the cutting and machining operations took less than 15 minutes some required less than a minute In these cases it was decided to perform the same operation several times during the sampling period The times will
be indicated
PRODUCED
J-M 83
C
For each operation except as otherwise indicated three replicate
short breathing zone samples were collected for the operator and for
his helper
Simultaneously longer personal samples were collected on the operator and his helper over a period of two to three hours and covering more than one type of field operation Also integrated area samples were collected
at a site approximately 15 feet away and downwind if there was air movement
Other area samplers located 1 to 5 feet from the field operations were used to collect total dust and respirable dust by weight Samples used for total dust were changed every 4 hours those for respirable dust every 8 hours Three such samples were used to determine quartz content Background samples were collected before and after each day's operations
Air samples were collected on millimeter diameter 0.8 micron pore size Millipore cellulose ester membrane filters in accordance with OSHA and NIOSH recommendations They were all open with the cover of the filter
cassette removed samples Personal sampling pumps were operated at flow rates
ranging from 1.6 to 2 liters per minute The pumps were calibrated by the soap
bubble technique before use Both area and personal breathing samples
were taken In the latter the pump was attached to the worker's belt and the
filter clipped to his lapel near his face Figure 1 in the July 1977 Report
illustrates worker and helper with samplers in place Figure 2 in the same report shows the test site with area samplers located near the operation
Asbestos fiber counts were done by an experienced and accredited technician following OSHA and NIOSH methods The same technician was employed who had worked in the earlier C pipe study Briefly the analytic procedure consisted of rendering the filter transparent with a high viscosity solution of membrane filter material in a mixture of diethyl oxalate and dimethyl phthalate The
|
PRODUCED
JM - 83
asbestos fibers which lie on the surface of the filter are counted with a phase
contrast microscope at 400x magnification The count area was delineated with a Porton graticule Only fibers exceeding 5 micrometers in length were counted The laboratory examined 100 microscopic fields or counted 100 fibers whichever came first Fiber identification depended upon a particle having an aspect ratio of at least 3 and having approximately parallel sides No attempt was made to identify individual fibers mineralogically in view of the known chryso-
tile and crocidolite content of the material under examination Fibers which appeared not to be asbestos were noted when seen No estimate was made of the
number of fibers less than 5 micrometers in length nor the number in the electron microscope range Samples were stored for such studies if they should appear
desirable at some later time
It should be emphasized that estimates of fiber concentrations below
5 fibers are subject to increasing lack of precision and that those below 0.5 fibers have a wide margin of error often being based on the observation of very few fibers For example in a 15 minute sample one fiber observed
per 100 fields is equivalent to 0.05-0.07 fibers which is the approximate
lower limit of detection for this sampling period Although counts are reported as calculated to two decimal places small differences in counts in these ranges should not be overinterpreted A zero count merely means that the count was too
low for any fibers to be seen in 100 fields and is consistent with a very low
concentration of airborne fibers Samples for gravimetric dust concentrations were weighed in the laboratory of EEH Quartz analyses were performed by George Clayton Associates
Performance of study As in the previous study all of the operations were carried out on the premises of Pilot Mfg Co. a manufacturer of C pipe equip-
PRODUCED
JM - 83
ment in Torrance California except for unloading and placing in trench which were done on a job site in Alameda County California A workman experienced in the use of the tools performed the individual operations with a helper provided by EEH EEH independently purchased the necessary sewer pipe and pressure pipe for cutting and machining from a local supply house All pipe was 8 inches in diameter unless otherwise specified As before no engineering dust control or local ventilation was utilized except when this was built into the equipment being used as was true for some of the tests using the Doty tool and when wetting was added to the use of the abrasive disc
GENERAL DESCRIPTION OF OPERATIONS
The except for unloading and laying operationwass carried out during the period October 1-15 1977. Mrs. Barbara Kawahara was the industrial
hygienist and she was assisted by Mr. Jerry Flanery of the EEH staff The weather during the period was in general overcast with clearing skies in midmorning Temperatures during the test periods ranged from 16-21 C 60 to 70 F There was relatively little breeze in the mornings with gusty breezes up to 5 or 10 mph in the afternoons
Housekeeping In order to minimize contamination of the test area with
dust and scrap commercial vacuum cleaner was brought in to maintain a clean work area Unfortunately it was ineffective because of a worn gasket and blew
visible dust from its exhaust It was necessary to wet down the area periodi-
cally and sweep up loose scraps and dust
PRODUCEDPRODUCED .
JM PRODUCED
DETAILED DESCRIPTION OF OPERATIONS AND SAMPLING TIMES
1 Unloading This was done with a palletized load using a fork Figures 1 & 2 The pipe was arranged on 4 foot pallets 8 per bed plus miscellaneous short lengths and couplings It took approximately 15 minutes
to unload a bed truck Up until three or four years ago it had been customary for the pipes to be loaded individually by being rolled down skids
To unload a bed truck in this manner took about 2 hours
For this operation a single minute personal sample was collected on the fork operator while pressure pipe was being unloaded
2 Laying pipe in trench The operation which was studied involved
trenching laying pipe and filling simultaneously Figures 3-5 One worker
remained in the trench at the forward end of the pipe The second worker worked both topside and in the trench He attached a clamp to the pipe lubricated the end then got into the trench to help guide it into place for coupling Two 1-1 hour samples were collected by personal samplers placed on the two workers
3a Cutting with manual saw Figure 6 Due to the inability to pro-
cure an appropriate bow saw blade a standard hack saw was used with a hardened
steel blade The blade was changed before each run Sampling times ranged from 12 to 15 minutes during which time it was possible to cut about half
way through the 8 pressure pipe This tool was not used with sewer pipe 3b Cutting with snap cutting equipment For this portion of the study
a Wheeler Chain Cutter Model 2990 was used It has cutting discs mounted on a chain which is wrapped around the pipe Figures 7 & 8 The action is controlled hydraulically by an operator who can stand as far as 10 to 15 feet from the pipe being cut The set between cuts took about two minutes Pumping to build up pressure required about 15 seconds Five to 8 cuts were
PRODUCED
JM PRODUCED
made during each sampling period the average ranged from 14 to 16 minutes for sewer pipe and 13 to 16 minutes for pressure pipe
3c Cutting with abrasive disc wet A gasoline abrasive disc
saw Stihl with a inch carbide blade was used Figures 9-11 Four 1/4
inch diameter plastic hoses were mounted on the housing of the saw two on a
side as shown in Figure 10 in accordance with TAC Ltd. blueprints provided by
AACPP These were connected to a manifold to which was attached a hose deliver-
ing water at a rate of 2 to 3 gallons per minute A preliminary run was with a saw that proved to be underpowered requiring
18 minutes for two cuts With a more powerful saw 1-1 hp motor a cut could
be completed in approximately 1-1 minutes Two to 3 cuts were taken per sample
the sampling periods having been reduced to 3 to 6 minutes after an initial test
sampling period of 17 minutes had led to overloading of the filter with dust This test was run on pressure pipe only
4a Cutting and machining with Doty tool The Doty tool Figures 12-15
has two operating stations one for cutting and one for machining It has
three operating modes dry dry with shroud and wet with shroud The last
two modifications were to reduce dust generation and dispersion During tests
of the tool in the dry mode with shroud and wet mode with shroud a olastic
bag was placed over the blade to reduce dust Figure 13
All cuts were made wet because a diamond blade is used A fine spray of
water is directed across the blade during operations About half minute
is required for a single cut
Machining was done dry with no shroud dry with shroud and wet with
shroud Again for the wet mode a fine spray was used Machining took about 1 minute Most of the sampling time involved moving pipe Use of the Doty tool is essentially a one operation a helper being needed only to move
large pipes
-
PRODUCED
JM PRODUCED
C<
Two to four cuts and two to four machine operations were completed per
sample cycle Sampling time was reduced from approximately 15 minutes to
approximately 10 minutes for the dry mode because it raised visible dust It
was observed that on the dry mode with shroud tests visible dust was released
during bevelling It is suggested that a gasket or some other seal would be
helpful in preventing this
Sampling times recorded for the use of the Doty tool wet for pressure
pipe were 10 to 11 minutes and for sewer pipe 9 to 15 minutes For use of Doty
tool dry with shroud with pressure pipe the sampling times were 13 to 17 minutes and for the sewer pipe 12 to 14 minutes For the use wet with shroud 13 to 18
minute sampling times were employed for pressure pipe 12 to 16 minutes for
sewer pipe
4b Use of tapering tool with A air duct pipe Test of the tapering
tool Figure 16 was limited to inch / air duct pipe which has a thick-
ness of approximately 1/4 inch Its operating principle is similar to that of
the manual field lathe Sampling times ranged from 14 to 22 minutes which
included one cut and one tapering operation
4c Machining with manual lathe on differing sizes of pipe In order
to determine whether or not the size of pipe had a detectable influence on dust
production a manual lathing operation was carried out on pressure pipe of inch inch and inch diameter Figures 17 & 18 For the inch pipe there was
one cut and one machining for each sample set requiring about 3 minutes cut
requiring about 3 minutes second set about 4 minutes and machining about 8 minutes the sampling times for the three replications being 13 to 21 minutes
For inch pipe again one cut and one machining was carried out for each sample the set requiring about 3-1 minutes the cut about 2 minutes second set requiring about 2 minutes and machining about 10 minutes The
PRODUCED
JM - 83
replicate samples ranged from 19 to 21 minutes For the inch pipe there was one partial cut per sample each sample included some machining and some cutting The set required 3 minutes the cutting about 12 minutes the second set about 2 minutes and machining about 20 minutes
5a Hole cutting with drill and rasp For this operation Figures 19-21 inch holes were drilled on the pipe in a circular pattern of about 6 inches in diameter after which the central portion was knocked out with a hammer and the rough edges smoothed with a rasp The operator used the exhaust air from the drill to blow off excess dust Figure 22 Although the practice of blowing
asbestos dust is not recommended it was used in this instance to duplicate worst possible work practices or tool performance characteristics The drilling
took a long time to complete so that only about 3/4 of the circumference was finished in one sampling period Therefore some samples did not include the hammer and file steps Sampling times for pressure pipe ranged from 16 to 24 minutes for sewer pipe from 17 to 21 minutes
6a Tapping operations with Mueller J tool Figure 23 The Mueller J
tool is used for tapping pipes not pressurized the trench top or in the
trench
In the latter case a hole is dug to expose the pipe but for the
test a pipe which had not been installed was employed A manually operated
tool was used which cuts a hole and threads it Two inch holes were cut
per sampling period Sampling periods for pressure pipe were 14 to 19 minutes 6b Tapping operations with Mueller 100 tool The Mueller 8-100 tool
Figure 24 is used for tapping pipes already in line usually those under
pressure It has a pressure chamber to keep the water from flowing out during
the tests At the recommendation of the local Mueller representative this chamber was filled with water to simulate wet conditions during the tests There
were two holes cut per sampling period the sampling times were 14 to 19 minutes
PRODUCED
JM PRODUCED
c
10
7a Removal of coupling with hammer and chisel For pressure pipe a hammer and chisel were used to make a longitudinal trough in the coupling Figure 25 When this had been completed a crowbar was used to separate the coupling For pressure pipe this took about 22 minutes one coupling being
removed per sample With sewer pipe the same procedure took about 10 minutes
per sample It was soon found that by placing the chisel midline on the coupling one or two sharp hits would split the coupling a procedure which took only 1030 seconds per coupling For sewer pipe 3 to 4 couplings were cut per sample the major portion of the sampling time being during moving pipe and securing it
to supports
Cc
Order of tests Availability of equipment and efficient use of pipe and manpower led to the actual tests being carried out in an order different from that summarized in the foregoing outline The order of testing was as follows
Monday October 10 1977
Cutting with snap cutting equipment pressure pipe 3b Cutting with hack saw pressure pipe 3a
Machining with manual Machining with manual
lathe lathe
inch pressure inch pressure
pipe pipe
5c 5c
Machining with manual lathe inch pressure pipe 5c Hole cutting with drill and rasp pressure pipe 5a
Tuesday October 11 1977
Coupling removal hammer and chisel pressure pipe 7a Tap with Mueller J pressure pipe 6a Tap with Mueller 100 pressure pipe 6b Tap with Mueller 100 sewer pipe 6b Tap with Mueller J sewer pipe 6a Use of tapering tool on / air duct 4b Cutting with snap cutting equipment sewer pipe 3b
PRODUCED =.
JM PRODUCED
C
11
Wednesday October 12 1977
Cutting with hack saw sewer pipe 3a Hole cutting with drill and rasp sewer pipe 5a Cutting with abrasive disc wet pressure pipe 3c Removal of coupling with hammer and chisel sewer pipe
7a
Thursday October 14 1977
Cutting and machining with Doty tool dry pressure pipe 4a
Cutting and machining with Doty tool dry shroud pressure pipe 4a
Cutting and machining with Doty tool wet shroud pressure pipe 4a
Cutting Cutting
and machining with and machining with
Doty Doty
tool tool
dry dry
sewer pipe 4a
shroud sewer pipe
4a
Cutting and machining with Doty tool wet shroud sewer pipe 4a
Friday October 15 1977
Cutting Cutting
with with
abrasive abrasive
disc disc
wet wet
pressure pipe 3c sewer pipe 3c
Testing at Bay Area site Unloading pipe at site 1 Laying pipe in trench 2
Integrated term samples were taken as shown in the tables of
results
RESULTS
fe
The short or peak exposures during the operations studied are shown in Tables 1-6 Integrated personal samples analyzed for asbestos fiber concentrations are shown in Table 7. Table 8 summarizes integrated area samples which were studied for asbestos fiber concentrations total dust respirable dust and quartz content as shown None of the respirable samples i.e. samples collected with a filter cyclone to remove large respirable
PRODUCED PRODUCED
PRODUCED PRODUCED
12
ra
particles showed a measurable amount of dust sufficient for quartz analysis Table 9 summarizes background levels
DISCUSSION
a f
Background levels as in the previous study were at the limit of sensitivity for the volumes of air and the methods employed Ranging from below the level of detection to 0.07 fibers they indicate low concentrations similar
to those found in many earlier studies
Short or peak exposures All operations that were studied produced airborne concentrations far below the current short standard of 10 fibers or the proposed short standard of 5 fibers except for some operations using the Doty tool and operations using the abrasive disc saw Some operations
using the Doty tool particularly when used dry although below the permissible
concentrations for short exposures would if continued over an hour day exceed the permissible time weighted average of 2.0 fibers It is of course unlikely that use would be continuous
The abrasive disc saw even when used wet produced unacceptably high concentrations of airborne fibers averages ranging from 10 to 65 fibers
It is believed that use of water to cut down dust with this machine could be
improved upon Because the hose was attached to the housing and the latter
could be rotated with respect to the handle of the saw the water was not invar-
iably directed to the cutting area It was observed also that dust was generated within the pipe during the cutting and would exhaust from the ends of the pipe and this could not be reduced by water applied to the outside of the pipe Also although the outside of the pipe was thoroughly wet as the cut proceeded the disc would generate heat and dry an area on either side of the blade It is
13
recommended that water be applied through a fine spray spread over a wide field so that nozzle placement would not be critical We do not feel that the wet-
cutting modification employed in our tests was designed to cover all conditions
of tool positioning and usage therefore the possibility of effective dust re-
duction with a proper method of wetting should not be ruled out
The quartz analyses which employed ray diffraction methods which would
be used by OSHA and most industrial hygienists showed more than % quartz in
- each of the total dust samples that were analyzed specifically 5.7 9.0 and
15.4 The threshold limit value i.e. the permissible weighted average
for total containing dust is 30 mg
.
% quartz + 3
Therefore in the three
samples measured the range of TWA's would have been from 1.6 to 2.6 m
No concentrations this high were reported in the integrated samples collected
during the current studies The high levels reported in the previous survey
were peak not integrated samples
SUMMARY AND CONCLUSIONS
>
Summary and Conclusions
Determinations were made of airborne asbestos fiber concentrations total dust and respirable dust concentrations and crystalline silica concentrations during a number of field operations used in the cutting machining and installation of asbestos pipe These were designed to supplement studies reported in 1977 which showed that potential asbestos exposures during most operations were well below current occupational health standards but that one tool the abrasive disc saw resulted in unacceptably high concentrations of
fibers In addition short term concentrations of total dust suggested that if
crystalline silica content was high permissible levels might be exceeded
The additional studies included a test of the abrasive disc saw with an
attachment for wetting the area being cut tests in which concentrations of crystalline silica were determined as well as tests of several operations not
previously studied Specifically the following operations were included
1 unloading of pressure pipe at the work site 2 laying pressure pipe in a trench 3 cutting pressure pipe with a manual saw cutting pressure and sewer pipe with snap cutting equipment cutting pressure and sewer pipe with an abrasive disc wet 4 cutting and machining pressure and sewer pipe with a Doty tool with various modifications wet and dry use of tapering tool on air duct pipe machining differing sizes of pressure pipe 4- 8- and inch with a manual lathe 5 hole cutting pressure and sewer pipe with drill and rasp 6 dry tapping pressure and sewer pipe with a Mueller J tool wet tapping pressure and sewer pipe with a Mueller 100 tool and 7 removing coupling
from pressure and sewer pipe with hammer and chisel All operations that were studied produced airborne concentrations of asbestos
far below the current short term OSHA standard of 10 fibers >5um in length and none would have exceeded a weighted average of 2 ml or even 0.5 ml
if continued for a full working day except for 1 the abrasive disc saw and 2 some operations with the Doty tool when used dry The abrasive disc even
when used wet resulted in fiber concentrations ranging from 10 to 65 ml It was concluded that better design of the wetting method was essential The con-
centrations observed with the Doty tool dry were below short standards
and would have exceeded the time weighted average of 2 ml only in the unlikely event of being used continuously over a full work day
Integrated total dust samples contained 5.7 9.0 and 15.4 quartz This
meant that permissible weighted averages would have ranged from 1.6 to 2.6
cubic meter The only integrated sample that exceeded the current OSHA standard
was that collected during use of the abrasive disc saw These additional studies confirm that asbestos pipe can be cut
machined and installed without exceeding current and proposed OSHA standards but that use of proper tools and adherance to recommended work practices are
essential
14
Table 1
Airborne Fiber Concentrations During Unloading of Pressure Pipe and Laying Pipe in Trench
Operation Unloading pipe Laying pipe Laying pipe Background
Duration min
2 2 32
Fibers
m
0.03
%
0 0.02
0 bd
Below detectable limit
y
4
...
Table 2
Airborne Fiber Concentrations During Cutting Operations with Hack Saw Snap Cutting and Use of Abrasive Disc Het
A Pressure Pipe
Operator
Duration
min
Fibers ml
Helper
Duration
min
Fibers
ml
A Sewer Pipe
Operator
Duration
min
Fibers
ml
Helper
Duration
min
Fibers
m
Hack saw
15
15
12
Mean
Snap cutting
545
14
15
Mean
Abrasive disc
17
Wet
6
3
4
Mean
0.06 0 0 0.01
0 0 0.07 0.02
30.4 60.1 25.8 109.1 65.0
552
0.05
552
0.21
552
0.07
0.11
16
0
20
0
20
0
0
1545
30.9
1545
54
1545
46
1545
47.5
49.2
18
0.11
17
0.23
15
0.19
0.18
15
0
15
0.07
16
0.06
0.04
556
95.3
556
19.8
556
11.3
42.1
16
0
655
0.17
15
0.06
0.08
15
0.05
225
0.06
225
0.05
0.05
556
14.4
556
8.4
556
7.8
10.2
Filter overloaded not used in calculating mean
J- M PRODUCED
83 PRODUCED
15
Table 3
Airborne Fiber Concentrations During Machining Operations
Operation
Operation
Cutting & Machining with Doty Tool Dry
Mean
Dry Shroud
Mean
Wet Shroud
Mean
A Pressure Pipe
Operator
Duration
min
Fibers
m
Helper
Duration
min
Fibers
ml
11
3.75
22
1.62
22
0.32
1.9
16
0.3
588
1.56
588
2.02
1.29
18
0.18
14
0.29
16
0.15
0.21
=
1.37
29
2.15
10
3.18
2.23
17
0.19
13
0.24
14
0.11
0.18
285
0.47
285
0.18
285
0.15
0.27
PRODUCED
PRODUCED PRODUCED
PRODUCED
PRODUCED
PRODUCED
A Sewer Pipe
Operator
Duration
min
Fibers
m
Helper
Duration
min
Fibers
ml
15
1.13
10
8.91
509
1.44
3.83
NO2
0.23
NO2
0.25
NO2
0.20
0.23
14
0.17
12
0.14
16
0.30
0.20
15
0.32
10
0.48
9
0.08
0.29
583
0
583
0.06
583
0.20
0.09
14
0
12
0
15
0.11
0.04
4
16
Table 4
Effect of Size of Pipe Upon Airborne Fiber Concentrations During Machining With Manual Lathe
Operation
Operation
Manual lathe
inch pipe
Mean
inch pipe
Mean
{ inch pipe
Mean
Operator
Duration min
Fibers
ml
18
OOOO
19
OOOO
20
OOOO
OOOO
22
0.04
19
0
21
0.05
0.03
18
0
15
0
19
0.05
0.02
Helper
Duration
min
Fibers
ml
18
0
19
0
21
0.05
0.02
222
0.07
20
0.24
21
0.07
0.13
18
0.05
15
0.07
20
0.05
0.06
18
Table 5
Airborne Fiber Concentrations During Use of Tapering Tool with C Air Duct Pipe
Tapering tool
with air duct
pipe
Mean
Operator
Duration
min
Fibers
ml
14
0.28
23
0.13
14
0.14
0.18
Helper
Duration
min
Fibers ml
14
0.06
22
0
15
0
0.02
PRODUCED
PRODUC8E3D
Table 6
Airborne Fiber Concentrations During Hole Cutting Tapping Operations and Coupling Removal
Operation
Hole Cutting with Drill and Rasp
Mean
Pressure Pipe
Operator
Helper
Duration
min
Fibers
ml
Duration
min
Fibers
ml
Sewer Pipe
Operator
Helper
Duration
min
Fibers
ml
Duration
min
Fibers
ml
296
0.18
296
0.14
16
0.33
0.22
287
0.08
287
0.11
17
0
0.06
255
0.28
255
0.17
17
0.23
0.23
21
0.25
17
0.15
18
oO *
0.13
Dry Tap with
Mueller J
Mean
179
0.06
179
0.09
19
0
0.05
15
0.06
17
0.10
19
0.05
0.07
18
0.07
16
0.12
15
0
0.06
15
0.05
16
0
15
0.05
0.03
Wet Tap with
Mueller 100
Mean
PRODUCED
PRODUCED
PJRMOBDUCED Removal PRODUCED and Chisel
PRODUCED
PRODUCED
Mean
PRODUCED
19
0.17
228
0
14
0.17
0.11
22
0.29
265
0.30
15
0.32
0.30
* Plus Plus One 1 Glass Fiber
19
0.14
18
0.20
14
0.06
0.13
24
0.11
15
0.12
16
0.06
0.10
14
0.17
18
0
15
0
0.06
12
0.12
12
0.07
9
0
0.06
14
0
16
0
19
i]
0
13
0.12
13
0
9
0.18
0.10
19
c
20 Table 7
Integrated Personal Samples Covering Successive Operations
Operation
Snap cutting pressure
Hack saw pressure Manual field lathe 8
Manual field lathe Manual field lathe
Hole drilling
4 16
Coupling hammer and chisel
Mueller J pressure Mueller 100 pressure Mueller 100 sewer
ueller ueller sewer Tapering tool duct Cutting cutting
Cutting hack saw sewer Hole drilling sewer Abrasive disc wet pressure
Coupling removal sewer
Doty Doty Doty Doty Doty Doty
tool tool tool tool tool tool
dry dry wet dry dry
wet
pressure
shroud pressure shroud pressure
sewer
shroud sewer shroud sewer
Abrasive disc wet pressure Abrasive disc wet sewer
Average Peak
Counts
Integrated Sample Counts
Operator Helper
Fibers Fibers
ml
ml
Operator
Helper
Duration
min
Fibers Duration
ml
min
Fibers
ml
0.02 0.01 0.03
0 0.11
0.13
0
0.02
|
0.02
0.06
}
0.22
0.06
]
\ 0.3
0.05
0.1 0.07
] 0.11
0.06
0.13
0.0
0.06
0.03
|
0.18
0.02
}
0.04
0.05
J
0.18
0.08
:
f 0.23
4.30
0.13 0.79
0.06
0.10
}
1.90 1.29 0.21 3.83 0.23 0.20
2.23 0.18 0.27 0.29 0.09 0.05
i 65.02
42.1
49.15 10.22
250
0.02
250
0.11
228
0.08
229
0.02
275
0.05
279
0.04
,
226
0.06
226
0.02
264 132
0.34 0.05
263 178
0.14 0.03
237
0.35
237
0.26
69
5.84
74
5.80
Motor underpowered only one test tried
T
PRODUCED JM - 83
21 Table 8
Integrated Area Samples Covering Successive Operations
Area Samples
Asbestos Fibers
Total Dust
Operations
Snap cutting pressure pipe
Hack saw cutting pressure pipe
Manual field lathe 8 pressure
Manual field lathe Manual field lathe
Hole drilling
4 pressure 16 pressure
Duration
min
.
Fibers ml
Duration
min
k 251
0.57
252
\ 234
0.04
235
m
mg
0.33
0.31
Coupling removal hammer
and chisel
Dry tap Mueller J pressure Wet tap Mueller 100
pressure
Dry tap Mueller 100 sewer
Dry tap Mueller J Tapering tool with
duct pipe Snap cutting sewer
sewerpipe C air
pipe
+ 286
~~
r 225
0.02 0.02
290
0.34
233
0.00
Hack saw cutting sewer pipe Hole drilling sewer pipe Wet abrasive disc pressure
pipe
Coupling removal sewer pipe
| 272
j
}
17
0.08 0.02
272
0.12
191
0.79
Quartz
Content
}-
11.1
|
5.7
|
22
Table 8 Cont'd
Integrated Area Samples Covering Successive Operations
Operations
Cutting and machining Doty dry pressure
Cutting and machining dry shroud pressure
Cutting and machining
wet shroud pressure Cutting and machining
wet shroud pressure Cutting and machining
dry sewer Cutting and machining
dry shroud sewer Cutting and machining
wet shroud pressure
Abrasive disc wet
pressure pipe
Abrasive disc wet
pipe
sewer
Area Samples
Asbestos Fibers
Total Dust
Duration
min
Fibers m1
Duration
min
m
mg
Quartz
Content
238
0.03
240
0.20
Not
|
Deter-
*
mined
80
3.83
82
1.66
b
15.4
333
Table 9
Airborne Fiber Concentrations Before and After Operations Background Levels
Date and Time
October 10 1977 am October 10 1977 pm
October 11 1977 am October 11 1977 pm
October 12 1977 am October 12 1977 pm
October 14 1977 am October 14 1977 pm
October 15 1977 am October 15 1977 pm
Duration
min
QU QU
ON ON
UN UN
129 ON
UN UN
Fibers
m1
* 0.02
0.07 0.0
0.01 0
0.002 0
0.01 0
Below detectable limit
tine Sor ctae
oT
a
ag
meth
ities eet, ge aa"
Ri
> any Sp iS
Re .
ae Ont ah. :
Pe te
-,
TT me
n'y x"
Nierein nae Rat irtd tae te f
Ss
2
teen
ae e : S
4
ae
eeake
Ud
BRENT
OR ry C ot SaaL t TLep SAere eeAde
wt,
lag
ae
E 3s
aoe
ees
yar
> ed p
Liens eee
4
ene,
A
TA etry
Naan
3
:
=a, va
erga
:
-
Ts pa
ee hie pane SG eH o
Stal
ve,
a
rg RON
See
aegis
SARE
>
rere
te
Sees,
Sef aie CHE SMA
eee PAROS CEES
FIGURE 1. Unloading inch pressure pipe at
work site
Rod
ea
%
TA Saetsetel 7 -
,
eS
ae
.
a iaedt "
Eaed
elton SM ge 5
ACLS
oats
o a4
ie
ioS]
FIGURE 2. Transporting inch pressure pipe from
truck to trench
PRODUCEDPRODUCED PRODUCED
.
PRODUCED -
PRODUCED
FIGURE 3. Placing pipe at side of trench
ee
arse
ie RIT a AOS
igus, erent
ee
G Reg Soo
Sues
FIGURE 5. Positioning in trench
wut
shes Per ay?
ry
tres!
3
hed te
:
3
Rn Os te Vee, ern Py 'OS Tab ae ee *
FIGURE 6. Cutting with hack saw
y
4 s
ee
roth es > iE
eae, a7.) aay
NG Wiel cae os
FIGURE 7. Snap cutting tool
eee ect
we
S : |e
72,
iba, a, he
f
c
Fae
i]
v9 Ts. we
weTe HF n tae
he
3 eS
-
hy .
ae
" "
wy
zs
I
s.
Ly,
by eo
5 peal
PRODUCED
PRODUCED
FIGURE 8. Hydraulic control of snap cutting equipment PRODUCED
PRODUCED
83
FIGURE 9. Abrasive
wet cutting
disc
saw with
hoses
for
a
ent 4 ater REE
Eh
rT witats
e
AOL
ve
ere...
*
tis Times
A
eoing:
Al
eres,
Be
FIGURE 10.
JPMPRROODDUCUECE Abrasive disc saw with hoses for wet cutting
PRODUCE
PRODUCE PRODUCE
PRODUCE
S59
pea
a aalt gees BRA,
tend S) meget
* fA
.
ae
Bat aed5:
pny =
aavsAU, . .
el ati
a
FIGURE 11. Use of abrasive disc saw wet
are tera TV ve pat
; Pod 4 for Ua y
FIGURE 12. Ooty tool cutting
FIGURE 13. Doty tool cutting with bag around blade
|
|
=
-
qT PRODUCED FIGURE 14. Doty tool machining with shroud
PRODUCED
PRODUCED
FIGURE 15. shroud
Doty tool machining dry without
20S
xy
ws
ave
b
omy
*
itn
wig,
Pile Zane Sid kay
pa aad 1a
FIGURE 16. Tapering A air duct
PRODUCED PRODUCED
{f
FIGURE 17. Use of manual
pressure pipe
lathe on
inch
C
. FIGURE 18. Use of manual lathe on inch pressure pipe
FIGURE 19. Cutting hole with drill
he
Fe sa)gen
5a
Sy
Sah
ne ded 95
FIGURE 20. Knocking central portion with hammer
VE:
62) Ad
RR ^' ay
aatiOL we
wy pa
~
et
f fhe
ene
oat" aes
aw
FIGURE 21. Smoothing rough edges with rasp
why
4
a
FIGURE 22. Blowing dust with exhaust
FIGURE 23. Use of Mueller J tool
cn
oe At
*
a
segue Tas ete RE
PO i
te 24 > bat A
oe ENG iw Rk.
ye
Pr jin a"
Se ie
io
= F,
Rae ee . Ne a!
12
as
P.Wir
FIGURE 24. Mueller 100 tool
7
eis
FIGURE 25. Removal of coupling with chisel