Testing Results

silica dust generating activities in the area, the frequency of and method used to empty the
extractor, and the number and depth of the holes drilled.
• Overheard drilling results in the higher potential exposure to silica dust than other drilling
orientations, such as drilling downward or horizontal. Since these positions will result in
equal or lower TWA’s, the maximum number of holes stated below for an 8-hour shift are
representative.
• Details on how to properly implement the 48-03-3035/3135 as a part of a complete exposure
plan are outlined below*:
Maximum Number of Holes per Day**
Hole Diameter
3/16"
1/4"
3/8"
1/2"
5/8"
¾”
7/8”
Hole Depth
1”
1,200
675
300
169
108
75
55
1-1/2"
800
450
200
113
72
50
37
2"
600
338
150
84
54
38
28
2-1/2"
480
270
120
68
43
30
22
3"
400
225
100
56
39
25
18
3-1/2"
343
193
86
48
31
21
16
4"
300
169
75
42
27
19
14
4-1/2”
267
150
67
38
24
17
12
5”
240
135
60
34
22
15
11
5-1/2”
218
123
55
31
20
14
10
6”
200
113
50
28
18
13
9
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.
* These calculations are offered for reference and are calculated values based on previously recorded test data.
** The user must drill the same number or fewer holes 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.