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MSHA -  Title 30 CFR
Appendix to Part 62

                     Table 62-1--Reference Duration
------------------------------------------------------------------------
                            dBA                               T (hours)
------------------------------------------------------------------------
80........................................................         32.0
85........................................................         16.0
86........................................................         13.9
87........................................................         12.1
88........................................................         10.6
89........................................................          9.2
90........................................................          8.0
91........................................................          7.0
92........................................................          6.1
93........................................................          5.3
94........................................................          4.6
95........................................................          4.0
96........................................................          3.5
97........................................................          3.0
98........................................................          2.6
99........................................................          2.3
100.......................................................          2.0
101.......................................................          1.7
102.......................................................          1.5
103.......................................................          1.3
104.......................................................          1.1
105.......................................................          1.0
106.......................................................          0.87
107.......................................................          0.76
108.......................................................          0.66
109.......................................................          0.57
110.......................................................          0.50
111.......................................................          0.44
112.......................................................          0.38
113.......................................................          0.33
114.......................................................          0.29
115.......................................................          0.25
------------------------------------------------------------------------
At no time shall any excursion exceed 115 dBA. For any value, the
  reference duration (T) in hours is computed by: T = 8/2(L-90)/5 where
  L is the measured A-weighted, slow-response sound pressure level.


                  Table 62-2--``Dose''TWA 8 Equivalent
------------------------------------------------------------------------
                                                                 TWA\8\
                             Dose                              (percent)
------------------------------------------------------------------------
25...........................................................        80
29...........................................................        81
33...........................................................        82
38...........................................................        83
44...........................................................        84
50...........................................................        85
57...........................................................        86
66...........................................................        87
76...........................................................        88
87...........................................................        89
100..........................................................        90
115..........................................................        91
132..........................................................        92
152..........................................................        93
174..........................................................        94
200..........................................................        95
230..........................................................        96
264..........................................................        97
303..........................................................        98
350..........................................................        99
400..........................................................       100
460..........................................................       101
530..........................................................       102
610..........................................................       103
700..........................................................       104
800..........................................................       105
920..........................................................       106
1056.........................................................       107
1213.........................................................       108
1393.........................................................       109
1600.........................................................       110
1838.........................................................       111
2111.........................................................       112
2425.........................................................       113
2786.........................................................       114
3200.........................................................       115
------------------------------------------------------------------------
Interpolate between the values found in this Table, or extend the Table,
  by using the formula: TWA8 = 16.61 log10 (D/100) + 90.


    Table 62-3--Age Correction Value in Decibels for Males (Selected
                              Frequencies)
------------------------------------------------------------------------
                                                            kHz
                   Age (years)                   -----------------------
                                                     2       3       4
------------------------------------------------------------------------
20 or less......................................       3       4       5
21..............................................       3       4       5
22..............................................       3       4       5
23..............................................       3       4       6
24..............................................       3       5       6
25..............................................       3       5       7
26..............................................       4       5       7
27..............................................       4       6       7
28..............................................       4       6       8
29..............................................       4       6       8
30..............................................       4       6       9
31..............................................       4       7       9
32..............................................       5       7      10
33..............................................       5       7      10
34..............................................       5       8      11
35..............................................       5       8      11
36..............................................       5       9      12
37..............................................       6       9      12
38..............................................       6       9      13
39..............................................       6      10      14
40..............................................       6      10      14
41..............................................       6      10      14
42..............................................       7      11      16
43..............................................       7      12      16
44..............................................       7      12      17
45..............................................       7      13      18
46..............................................       8      13      19
47..............................................       8      14      19
48..............................................       8      14      20
49..............................................       9      15      21
50..............................................       9      16      22
51..............................................       9      16      23
52..............................................      10      17      24
53..............................................      10      18      25
54..............................................      10      18      26
55..............................................      11      19      27
56..............................................      11      20      28
57..............................................      11      21      29
58..............................................      12      22      31
59..............................................      12      22      32
60 or more......................................      13      23      33
------------------------------------------------------------------------


   Table 62-4--Age Correction Value in Decibels for Females (Selected
                              Frequencies)
------------------------------------------------------------------------
                                                            kHz
                   Age (years)                   -----------------------
                                                     2       3       4
------------------------------------------------------------------------
20 or less......................................       4       3       3
21..............................................       4       4       3
22..............................................       4       4       4
23..............................................       5       4       4
24..............................................       5       4       4
25..............................................       5       4       4
26..............................................       5       5       4
27..............................................       5       5       5
28..............................................       5       5       5
29..............................................       5       5       5
30..............................................       6       5       5
31..............................................       6       6       5
32..............................................       6       6       6
33..............................................       6       6       6
34..............................................       6       6       6
35..............................................       6       7       7
36..............................................       7       7       7
37..............................................       7       7       7
38..............................................       7       7       7
39..............................................       7       8       8
40..............................................       7       8       8
41..............................................       8       8       8
42..............................................       8       9       9
43..............................................       8       9       9
44..............................................       8       9       9
45..............................................       8      10      10
46..............................................       9      10      10
47..............................................       9      10      11
48..............................................       9      11      11
49..............................................       9      11      11
50..............................................      10      11      12
51..............................................      10      11      12
52..............................................      10      12      13
53..............................................      10      13      13
54..............................................      11      13      14
55..............................................      11      14      14
56..............................................      11      14      15
57..............................................      11      15      15
58..............................................      12      15      16
59..............................................      12      16      16
60 or more......................................      12      16      17
------------------------------------------------------------------------