Document nkdyQZVnLQEvYVp8XgwyOaDyw
interoffice Aleiiioniiidiiiii
(Ntmi ana Location)
*As listed
FROM (Name and Location)
J.F. Stelluto - NYO
GEN 55 (REV.6/74)
DATE
5/3/82
REFERENCE NO.
JFS-42-82
- Dallas H.B. Brown - Virginia Chemicals H.J. Kolodner - Charlotte L.A. Hunt - Charlotte G.C. Miller - Charlotte A.D. Pantaleoni - Summit D.L. Unruh - Louisville
Subject: Asbestos Gloves
Attached is a copy of a recent article in the AIHA Journal on asbestos exposure from use of asbestos gloves. The article states that significant exposure to asbestos fibers can result from gloves that are well-worn.
Please advise if such an exposure exists in your locations and what steps, if any, have been taken to evaluate and control such exposures.
JFS:sl Att.
cc: J.C. Clary - NYO J.D. Dougherty - NYO V.A. Parrillo L. Starr -
J.F. Stelluto
PLAINTIFFS EXHIBIT
CEL-299
To assess the magnitude of fiber emission from asbestos gloves. 10 pairs were compared in an isolation chamber during simulation of a sterilization procedure; 1 76 air samples were collected. Means of time weighted average (TWA) concentrations ranged from 0.95 to 11.74 fibers (>5 im)/cm3 of air. Well-worn/clean gloves emitted significantly more fibers than did brand-new gloves, but fiber emission decreased with increased surface soiling. Eighty air samples were collected during simulation of the sterilization procedure in a well-ventilated room. The range of mean TWA concentrations was 0.07-0.99 fiber/cm* for breathing zone samples and 0.06-0.60 fiber/cm3 for area samples. Thirteen samples were collected at actual workplaces; the range of TWA concentra tions was 0.07-2.93 fibers/cm3 for breathing zone samples and 0.04-0.74 fiber/cm3 for area samples. Five of seven breathing zone samples from workplaces exceeded the proposed TWA concentration limit of 0.1 asbestos fiber/cm3. Hand contamination also was assessed. Four samples collected after touching the worktable ranged from 9953 to 13 1 08 fibers {>5 fim)/cm~ of hand surface area; seven samples collected immediately after taking off gloves ranged from 741 to 3860 fibers/cm3. Available substitutes for asbestos gloves are discussed, and adoption of these substitutes is recommended strongly.
Occupational exposure to asbestos fibers resulting from use of asbestos gloves
BEHZAD S. SAMIMI, Ph.D. and ANNA M. WILLIAMS. Ph.D. University of Wisconsin-Parkside. Kenosha. Wl 53141
introduction
Although the health hazards of exposure to asbestos in various occupations have been well documented,11"3* little attention has been given to the exposure of workers who wear asbestos gloves for handling hot objects. Asbestos gloves have been used commonly in hospital, industrial, and university laboratories where sterilization is done, and in hot industries such as foundries. A report on the similarity of asbestos fibers to a bacterial structure documented the con tamination of electron microscopy grids with asbestos fibers after asbestos gloves were tossed onto a laboratory table.14* However, a computer search of the literature, using six data bases, did not reveal any quantitative studies of fiber emis sion from asbestos gloves, or any discussion of possible exposure to asbesios via the respiratory or digestive tracts during use of these gloves.
Apparently, it has been assumed that wearing asbestos gloves does not expose workers to significant levels of asbes tos fibers, and these gloves are still being used despite the availability of non-asbestos gloves with comparable heat resistance. However, any degree of exposure to asbestos is now considered to increase the risk of asbestos-related dis eases such as mesothelioma, bronchogenic carcinoma, and digestive tract cancer. We have thus attempted to assess the health hazards associated with use of asbesios gloves by collecting personal and area air samples; 1) during simulated laboratory procedures in an isolation chamber and in a biology preparation room, and 2) during the actual work day of fiv e workers in their laboratories. It was observed that he workers usually did not wash their hands after handling .he gloves; therefore, experiments were included to estimate the extent of hand contamination during normal glove usage.
Cocrr>grtt 1901 Arr>**<*o
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materials and methods
Eight pairs of asbestos gloves in actual daily use were col lected from six microbiology and chemistry laboratories on two university campuses, and two new pairs were obtained from the UW-Parkside stockroom. All gloves were of the same type and were purchased from the same company. They were made from asbestos cloth which contained 80857c asbestos and 15-209! rayon. The cloth was treated with an acrylate-based compound and thus was described as "lint-free." The gloves were classified into the following groups based on structural integrity and apparent surface cleanliness; Group A, well-worn/clean, four pairs; Group B. well-worn/lightly soiled, three pairs; Group C, well-worn; heavily soiled, one pair; Group D. brand-new, two pairs. Representative gloves from each of the four groups, A-D. are show n in Figure I. To eliminate the effect of moisture, all gloves were kept in a dry incubator at 70 C until tested.
A ventless isolation chamber was used to determine air borne fiberemission from thegloves under controlled condi tions. during simulation of the operation used both for routine sterilization and for drying laboratory glassware. This operation consists of; I) picking the gloves up from the table top and putting them on; 2) opening the autoclave or oven door; 3) removing a tray containing the media or glassware and setting the tray on the table top: 4) closing the door: 5) taking the gloves off and tossing them onto the table top. The experimenter carried out these five steps inside the chamber after inserting his arms through two portholes in the front panel. The interval between consecutive operation' was 30 minutes, which represented a normal workload in UW-Parksidc's media preparation room. Air samples were
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TABLE I Concentration of Airborne Fibers (>5 iim) Emitted from Asbestos Gloves Tested in a
Non-Ventilated Isolation Chamber
Gloves ID *
Condition of
Gloves
No. of Samples
Cone. Of Fiber*/cmJ Mean r SD
A1 Wellworn/ctean A2 Wellworn/clean A3 Well-worn/clean A4 Well-worn/clean
Overall lor A Gloves
B1 Well* worn/lightly soiled
. 20 20 IB 20 78 20
6 20 2.36 5.82 1.53 8.12 2.90 11.74 1,16 7.97 * 3 14 (Mean) 5.09 0.86
82 Well-worn/lightly soiled
20
5.12 1 05
B3 Well-worn/lightly soiled
Overall for B Gloves:
Cl Well-worn/heavily soiled
D1 Brand-new
16
56 IS
24
5.02 1 89
5.08 1.27 (Mean) 0.95 0.16
2.25 0.57
collected inside the chamber, processed, and counted using the methods recommended by NIOSH.'5)
The same sterilization operation was also simulated in a well-ventilated biology preparation room which had five air changes per hour. Air samples were collected both from the breathing zone of the experimenter and from the work area. The interval between consecutive operations was either 30 minuies to represent the normal workload, or 10 minutes to represent a heavy workload.
The biology preparation room also was used to assess possible exposure to asbestos through ingestion of fibers on hajids. Contamination of hands from an approximately 0.6 m2 (6 ft2) work area of the laboratory table top was measured after an 8-hour simulated work shift with 16 uses of the gloves. The palm of one hand was touched to four different places 30 cm apart, in a line 15 cm in front of where the
TABLE II Comparison of Mean TWA Concentrations of Airborne Fibers Emitted from Asbestos Gloves
Using a priori Analysis of Variance
Gloves Compared
F Ratio
Probability
A vs B A vs C B vs. C A and B vs. D
109 4 290 4
93 8 83 8
<001 <001 <0 01 <0.01
gloves were tossed. The fibers were removed from the con taminated hand after each contact by immersing the hand in a 2-L beaker containing approximately 1.5 L of distilled water, followed by flushing the hand with a wash bottle. The water w'as poured through a membrane filter of0.45 pm pore size, and the filter was processed and counted using the methods recommended by \IOSH.ISl In a second experi ment, the amount of asbestos remaining on either one or both hands, immediately after removal of the gloves from the hands, was examined by washing with water as described above. Each hand was washed separately when both hands were sampled, but the two portions of wash water were poured through the same filter to yield one sample. Hand surface area was determined by making tracings of pertinent surfaces of the hands on paper and measuring the areas with a planimeter.
In the studies performed on the workers in their actual workplaces, air samples were collected from the breathing zone of each worker and from an area 75 cm above the table top where the gloves were laid or tossed.
results
One hundred seventy-six air samples were collected from the confined atmosphere of the isolation chamber during simu lation of the sterilization procedure with asbestos gloves. The mean TWA concentrations of airborne fibers >5 pm shown by these samples ranged from 0.95 to 11.74 fibers/cm3 (Table I). The minimum and maximum TWA concentra tions observed were 0.61 fibers/cm3 for gloves SCI and 16.5 fibers/cm3 for gloves FA3, respectively. The main factors influencing the magnitude of fiber emission seemed to be the
TABLE III TWA Concentration of Airborne Asbestos Fibers (>5 pm) in Personal and Area Samples Collected During Simulation of Work With Asbestos Gloves in a Well-Ventilated Biology Preparation Room
Gloves ID #
Work Load*
Breathing Zone
No. of
Mean
Samples TWAC SD
F Test: A vs. D
Work Area
No. of
Mean
Samples TWAC SD
F Test: A vs. D
A2 Normal A3 Normal 02 Normal A2 Heavy A3 Heavy 02 Heavy
8 10
4 5 6 7
0 49 0.11 027 i 0.18 0 07 0 02 0 99 0 22 0 74 0.22 0 51 0 21
F=7 6 P<0 05
F=9 6 PC0 01
8 10
4 6 6 6
0 40 0 09 0 20 0.14 0 06 0 02 0 60 0 12 0 60 0 18 0 26 0 08
F = 4 56 PC0 05
F = 28 P< 0 01
'Normal and Heavy designate usage o( gloves 2 limes and 6 times per hour, respectively.
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TABLE IV TWA Concentration of Airborne Asbestos Fibers (>5 ^m) in the Breathing Zone
and Work Area of Laboratory Employees Using Asbestos Gloves
Sampling Location
Operation
TWA Cone of Fibers/cm'
Glove Usage Breathing Work
/B hr Shift
Zone
Area
Glove
ID
UW-Parkside Media Prep Room
UW-Parkside Media Prep Room
Sterilizing in autoclave
Steriluing m autoclave and1 drying glassware in oven
UW-Parkside Biology Lab Killing rats in ether
Madison Lab 1
Drying glassware in oven
Madison Lab 2
Sterilizing in 5 autoclaves
14 times (Normal)
16 times (Normal) 36 times (Heavy)
48 times (Heavy)
28 times (Heavy)
41 times (Heavy)
.70
.46 .71 2 93
89
0.10
007
.30 82 .74
.67 B2 .51 B2
A1
A1
0.10
B2
0.04
A4
-ity of the gloves, determined by age and/or and the degree of surface soiling. The mean TWA concentrations from the four groups of gloves were compared using a priori analysis of variance.161 This test indicated that the differences observed between the means of TWA concentrations all were highly significant, with p <0.01 (Table II). Well-worn/clean gloves emitted almost 3 times as many fibers as did brand-new gloves: however, the magnitude of fiber emission from well-worn gloves decreased
with increased surface soilling. The mean tions for lightly and heavily soiled gloves i :re. respectively, 0.6 and 0.1 the value for clean used gloves.
Results of 80 personal and area samples collected from a well-ventilated biology preparation room, during simula tion of the sterilisation procedure with gloves in Groups A and D. are presented in Table III. The TWA concentrations of airborne fibers were considerably lower than those obtained in the ventless isolation chamber, evidently due to
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the dispersion of fibers within the room by the ventilation
no firm conclusions from the present cvidencc.""" Some
system. The TWAC values for breathing rone samples
investigators believe, however, that the smaller asbestos par
ranged from 0.05 to 0.61 fiber/cm'1 with normal workload
ticles are more significant in penetrating cells and causing
and from 0.27 to 1.25 fibers/cm* with heavy workload.
damage.'*" Although wc did not confirm the presence of
Corresponding TWAC ranges for area samples were 0.02-
asbestos fibers too small to be identified at 450X. the hands
0.52 and 0.15-0.81 fiber/cm3, respectively. The mean TWA
of the experimenter in our ingestion experiments probably
concentrations for Group A (well-worn;clean) gloves were
were contaminated with these smaller particles in addition to
compared with those for Group D (brand-new) gloves by
the significant numbers of fibers longer than 5 jim which
analysis of variance. The F values shown in Table III con
were counted.
firm the findings in the isolation chamber that the wcllworn/clean gloves emitted a significantly higher number of asbestos fibers into the atmosphere than did the brandnew gloves.
The present study shows that gradual soiling of gloves, particularly with sticky material such as microbiological media, reduces the extent of fiber emission, apparently by a coating action. On the other hand, repeated usage of the
Thirteen personal and area samples were collected from
gloves damages the surface integrity and promotes release of
the actual workplaces of five workers. Maximum and min
fibers. It was surprising to observe the ragged condition of
imum TWAC values w ere 2.93 and 0.07 fiber/ cm3 for breath
some of the gloves being used by workers: an example is
ing zone samples and 0.74 and 0.04 fiber,'cm3 for area sam
shown in Figure 2. Such gloves, which were not included in
ples (Table IV). With this limited number of samples, it was
our measurements, would be expected to emit more fibers
found that exposure levels depended more on the particular
than the well-worn gloves studied.
laboratory than on glove condition and workload, which were the main influencing factors under the controlled con ditions of the experiments shown in Table 111. For example, although the UW-Parkside and Madison Lab 2 workers were performing similar operations with Group A gloves at a heavy workload rate, the TWAC of the UW-Parkside worker was.29 times that of the Madison worker. There was an efficient exha.ust system over the row of five autoclaves in Madison Lab 2. Undoubtedly, differences in room size and arrangement, efficiency of the ventilation system, and amount of moisture on gloves would be important in deter mining relative exposures of workers using asbestos gloves in different laboratories.
Results from the hand contamination studies revealed significant numbers of fibers on the hands. Values for the four samples collected by touching the contaminated table, where gloves A3 had been tossed 16 times, ranged from 9953 to 13 108 (mean = I I 688) fibers (>5 fim)/cm! of hand surface area (palm side of hand). Values for seven samples collected from the hands immediately after removal of gloves A4 ranged from 741 to 3860(mean= 1925) fibers/cm* of hand surface area (both sides of hands).
With the exception of one workplace sample, the TWA concentrations of the breathing zone samples in the biology preparation room and actual workplaces did not exceed the current OSHA standard of two asbestos fibers/cm3. How ever, the NIOSH-OSHA Asbestos Work Group has recom mended lowering tiieTWAC limit for asbestos fibers toO.I fiber/cm3.1101 All mean TWAC values for breathing zone samples in the biology preparation room, except that for brand-new gloves with normal workload, exceeded this lower level, as did five of the seven breathing zone samples from the workplaces.
After surveying the literature on the relationship between industria-1 exposure to asbestos and later development of bronchial, lung, and digestive tract cancers, a reviewer con cluded that the data do not provide much evidence for a threshold or the existence of a clearly "safe" level of expo sure.*111 Thus, any unnecessary exposure to asbestos should bediscontinued. The NIOSH-OSHA Asbestos Work Group staled that even when exposure is controlled to levels below the proposed new standard, "there is no scientific basis for concluding that all asbestos-related cancers would be pre vented," and recommended the substitution of less hazard
ous materials where they exist.*101 Fortunately, various sub
discussion and conclusion
The results of this study suggest that the use of asbestos gloves exposes the wearer to potentially hazardous levels of asbestos. In addition to inhaling airborne fibers, workers may ingest an indefinite number of fibers present in the air and on their hands and clothing.*71 The fibers are apparently easily dislodged from the gloves during handling, and remain on the hands after the gloves are removed. Evidence for entry of asbestos fibers by the gastrointestinal route, including evidence for and against actual penetration of the
stitutes for asbestos gloves are available.1121 Gloves made of -- Zetex. a silica-bascd product, are advertised to withstand
continuous temperatures up to 593 0 C and higher tempera tures for short durations: those made of Nomex. a heatresistant nylon, arc claimed to withstand sustained exposure at 250 C and short exposure to thermal shock at 350 C. A silicone-rubber hand grip can be used for remov ing trays or small items from autoclaves and ovens. Considering the results of the present study, we strongly urge the adoption of these or similar substitutes for asbestos gloves.
gastrointestinal wall, has been rev iewed.*71 The authors con cluded that "penetration must be postulated even though the
acknowledgement
proof is not yet conclusive." They also presented evidence ' This study was supported by funds from Color Arts. Inc. ol
for and against the fibrogcnicity and I umorigenicity of short
Racine. The authors also wish to thank James Ventura and
fibers, including those which were identifiable only under
David Estano. Industrial Hygiene students, for their techni
the electron microscope, and concluded "that there can be
cal assistance.
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references
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2. Selikolf, I.J. and D.H.K. Lee: Asbestos and Disease, pp. 135-336. Academic Press. New York (1978).
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4. Hutchinson, W.G.. R.l. Harker and M.M. Allen: Compari son ol Rhapidosomes and Asbestos Microlibrils Science 200 1 401-1403 (1978).
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6. Sokal, R.R. and F.J. Rohlf: Introduction to Biostatistics. W.H. Freeman and Co.. San Francisco, CA (1973).
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8 Selikoff. I.J. and D.H.K. Lee: Asbestos and Disease, pp. 423-428 Academic Press. New York (1978).
9. Lee. D.H.K.: Biological Ellects ol Ingested Asbestos Report and Commentary. Environ. Health Perspect. 9 13-12211 974|.
10 NIOSH: Workplace Exposure to Asbestos, p 40HHS(NIOSH) Publication No 81-103. U. S Dept, of Health and Human Services. Cincinnati. OH (1980).
11. Schneiderman. M.A.: Digestive Syslem Cancer Among Persons Subjected to Occupational Inhalation of Asbestos Particles. A Literature Review with Emphasis on Dose Response Environ Health Perspect. 9.307-311 (1974).
12. Michaels. L. and S S. Chissick, ed.: Asbestos 'dot. Prop erties. Applications, and Hazards, p 329 John Wiley 5 Sons, Ltd., New York (1979).
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