30 CFR Appendix to Part 62

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗

dBA	T (hours)
80	32
85	16
86	13.9
87	12.1
88	10.6
89	9.2
90	8
91	7
92	6.1
93	5.3
94	4.6
95	4
96	3.5
97	3
98	2.6
99	2.3
100	2
101	1.7
102	1.5
103	1.3
104	1.1
105	1
106	0.87
107	0.76
108	0.66
109	0.57
110	0.5
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.

Dose	TWA8(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.

Age (years)	kHz
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
Age (years)	kHz
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

[64 FR 49630, Sept. 13, 1999, as amended at 65 FR 66929, Nov. 8, 2000]