MILWAUKEE TOOL
13135 West Lisbon Road • Brookfield WI 53005 • 262-781-3600
To Whom It May Concern,
Milwaukee®, in partnership with Industrial Hygiene Sciences, LLC, has conducted testing on the Milwaukee 8 Gallon Dust Extractor
(8960-20) paired with the M18™ FUEL™ 7”/9” Large Angle Grinder (2785-20), 7”/9” Large Angle Grinder Cutting Shroud (49-40-
6120), and 7” and 9” blades. Results show that the user will be below the Permissible Exposure Limit (PEL) as described by OSHA
29 CFR 1926.1153 when using the above combination, assuming it is used in accordance with manufacturer’s instructions. Testing
results and procedures are outlined below:
• All cutting was performed using a Milwaukee 8 Gallon Dust Extractor (8960-20) paired with the M18™ FUEL™ 7”/9”
Small Angle Grinder (2785-20), 7”/9” Large Angle Grinder Cutting Shroud (49-40-6120), and 7” and 9” blades
• The cutting was completed with the block placed on the ground
• Automatic Filter Cleaning was turned on
• Concrete blocks were poured from a 5000 PSI concrete mix.
• The room size was 12’9” x 26’5” x 8’
• The room surfaces were wiped down between trials to ensure accurate measurements
• Samples were collected on 3 piece 37 mm diameter preweighed PVC filter mounted in a BGI GK2.69 respirable dust
sampler, run at 4.2 lpm and connected to a Gilian 10i air sampling pump. A field blank was submitted with each day’s set of
samples.
• Samples were analyzed using OSHA ID-142 by the Wisconsin Occupational Health Laboratory, an AIHA Accredited
laboratory. The sampling method used meets the definition of respirable crystalline silica in 1926.1153 (a) and Appendix A
of the OSHA Respirable Crystalline Silica Standard (1926.1153).
• The Time Weighted Average (TWA) was calculated assuming zero exposure to respirable crystalline silica for the non-
sampled portion of a 480 minute (8 hour) shift. Longer exposure times, assuming that the dust exposures would be similar to
those collected in these trials, would likely result in higher TWAs. Factors, including, but not limited to the ventilation and
air flow patterns in the space where the work is done, how flat the grinder is held, the condition of the shroud brush, the silica
content of the concrete, how much grinding was done when the shroud is not on a full, flat surface, the presence of other
respirable silica dust generating activities in the area, how often the user knocks collected dust from the HEPA filter, how
aggressively the HEPA filter is knocked off and how the vacuum is cleaned could affect actual user exposures.
Unit Tested Blade Diameter
Average Sample
Duration
% Silica (Quartz)
in Sample
Average Respirable
Crystalline Silica
Conce ntration (μg/m³)
OSHA PEL in
1926.1153
7" 61.7 10 13.8 μg/m³ TWA 50 μg/m³
9" 59 10.2 30.3 μg/m³ TWA 50 μg/m³
*A 2-1/4” cutting depth X 1/8” cutting width reflects the highest dust generating application for this tool, suggesting that other wheel
depths and widths would also be compliant when using the Milwaukee 8 Gallon Dust Extractor
Details on how to properly implement as a part of a complete exposure plan are outlined below*:
7/64"
3/16"
5/32"
11/64"
1/8"
0.25"
303
176
212
192
265
0.5"
151
88
106
96
132
0.75"
101
58
70
64
88
1"
75
44
53
48
66
1.25"
60
35
42
38
53
1.5"
50
29
35
32
44
1.75"
43
25
30
27
37
2"
37
22
26
24
33
2.25"
33
19
23
21
29
* These calculations are offered for reference and are calculated values based on previously recorded test data and represent a full
work day of the tested application
** The user must cut the same depth and width or less than those listed above for the given application in order to be considered
compliant with the objective data clause of 29 CFR 1926.1153 OSHA regulation on crystalline silica dust.
It is the responsibility of the user to operate the tool in accordance with manufacturer’s instructions. For the latest listings of
approvals, visit milwaukeetool.com. For technical or service assistance, contact Milwaukee Customer Service at 1-800-729-3878.
7/64"
1/8"
5/32"
11/64"
1/8"
0.25"
232
135
162
147
203
0.5"
116
67
81
73
101
0.75"
77
45
54
49
67
1"
58
33
40
36
50
1.25"
46
27
32
29
40
Maximum Number of Feet cut per Hour **
Cutting Width
Cutting Depth
Cutting Width
Cutting Depth
9” Blade
7” Blade
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