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Subchapter 3. Compressed Air Safety Orders (Governing Work in Compressed Air)
Article 12. Suggestions for the Guidance of Compressed Air Workers

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Appendix B

The information contained in the following pages is adapted from the U. S. Navy Diving Tables and is to be used when an employee will enter a compressed air environment more than once within a 12-hour period.

The Division may accept alternate methods of decompression for repetitive exposures provided the licensed physician submits his proposed procedures to the Division for its review and approval.

The Department of the Navy is in no way liable for the use or misuse of Tables 3, 4, and 5.

Pressure
(psig)

Repetitive Groups
A B C D E F G H I J K L M N O Z
4 60 120 210 300                        
7 34 70 110 160 225 350                    
9 25 50 75 100 135 180 240 325                
11 20 35 55 75 100 125 160 195 245 315            
13 15 30 45 60 75 95 120 145 170 205 250 310        
16 5 15 25 40 50 60 80 100 120 140 160 190 220 270 310  
18 5 15 25 30 40 50 70 80 100 110 130 150 170 230 270 300
22 -- 10 15 25 30 40 50 60 70 80 90 110 140 150 200 240
27 -- 10 15 20 25 30 40 50 55 60 70 80 100 120 140 200
31 -- 5 10 15 20 30 35 40 45 50 60 70 80 100 130 170
36 -- 5 10 15 20 25 30 25 40 -- 50 60 70 90 110 150
40 -- 5 10 12 15 20 25 30 -- 40 -- 50 60 80 90 130
45 -- 5 7 10 15 20 22 25 30 -- 40 50 -- 60 80 120
49 -- -- 5 10 13 15 20 25 -- 30 -- 40 50 60 70 100
TABLE 3 INSTRUCTIONS FOR USE

The tabulated compressed air exposure times are in minutes. The times at the various pressures in each vertical column are the maximum exposures during which a compressed air worker will remain within the group listed at the head of the column.

To find the repetitive group designation enter the table on the exact or next greater working pressure than that to which exposed and select the listed exposure time exact or next greater than the actual exposure time. The repetitive group designation is indicated by the letter at the head of the vertical column where the selected exposure time is listed.

For example: An exposure in compressed air was for 45 minutes at 26 psig. To determine the repetitive group enter the table at 27 psig (the next greater tabulated exposure time, as 45 minutes is not listed), then move vertically to the top of the column where "H" is shown as the repetitive group.

OPEN AIR INTERVAL CREDIT TABLE

REPETITIVE GROUP AT END OF OPEN AIR INTERVAL
                Z           O N M L K J I H G F E D C B A
Z 0:10
0:22		 0:34 0:48 1:02 1:18 1:35 1:55 2:17 2:42 310 345 429 527 656 1005 1200*
O 0:10
0:23		 0:36 0:51 1:07 1:24 1:43 2:04 2:29 2:59 3:33 4:17 5:16 6:44 9:54 12:00*
N 0:10
0:24		 0:39 0:54 1:11 1:30 1:53 2:18 2:47 3:22 4:04 5:03 6:32 9:43 12:00*
M 0:10
0:25		 0:42 0:59 1:18 1:39 2:05 2:34 3:08 3:52 4:49 6:18 9:28 12:00*
REPETITIVE GROUP AT BEGINNING OF OPEN AIR INTERVAL (FROM TABLE 3) L 0:10
0:26		 0:45 1:04 1:25 1:49 2:19 2:53 3:35 4:35 6:02 9:12 12:00*
K 0:10
0:28		 0:49 1:11 1:35 2:03 2:38 3:21 4:19 5:48 8:58 12:00*
J 0:10
0:31		 0:54 1:19 1:47 2:30 3:04 4:02 5:40 8:40 12:00*
I 0:10
0:33		 0:59 1:29 2:02 2:44 3:43 5:12 8:21 12:00*
H 0:10
0:36		 1:06 1:41 2:23 3:20 4:49 7:59 12:00*
G 0:10
0:40		 1:15 1:59 2:58 4:25 7:35 12:00*
F 0:10
0:45		 1:29 2:28 3:57 7:05 12:00*
E 0:10
0:54		 1:57 3:22 6:32 12:00*
D 0:10
1:09		 2:38 5:48 12:00*
C 0:10
0:54		 2:49 12:00*
B 0:10
2:10		 12:00*
A 0:10
12:00*

TABLE 4

Repet.
Group

REPETITIVE EXPOSURE PRESSURE (psig)
18 22 27 31 36 40 45 49
A 7 6 5 4 4 3 3 3
B 17 13 11 9 8 7 7 6
C 25 21 17 15 13 11 10 10
D 37 29 24 20 18 16 14 13
E 49 38 30 26 23 20 18 16
F 61 47 36 31 28 24 22 20
G 73 56 44 37 32 29 26 24
H 87 66 52 43 28 33 30 27
I 101 76 61 50 43 38 34 31
J 116 87 70 57 48 43 38 34
K 138 99 79 64 54 47 43 38
L 161 111 88 72 61 53 48 42
M 187 124 97 80 68 58 52 47
N 213 142 107 87 73 64 57 51
O 241 150 117 96 80 70 62 55
Z 257 169 122 100 84 73 64 57

TABLE 5- INSTRUCTIONS FOR USE

The compressed air exposure times listed in this table are called "residual nitrogen times" and are the times a compressed air worker is to consider already spent in compressed air when starting a repetitive exposure to a specific pressure. They are in minutes.

Enter the table horizontally with the repetitive group designation from the Open Air Interval Credit Table (table 4). The time in each vertical column is the number of minutes that would be required (at the pressure listed at the head of the column) to saturate to the particular group.

For example: The final group designation from the Open Air Interval Credit Table (table 4) on the basis of a previous exposure and open air interval is "H." It is planned to re-enter compressed air at a pressure of 42 psig. What time must be added to the actual time spent in compressed air? Enter table 5 on row H. Since 42 psig is greater than 40 psig but less than 45 psig, use the longer time of 33 minutes. This means that the compressed air worker enters the compressed air environment as though the worker had already been at 42 psig for 33 minutes.

The exposure time listed in table 5 is added to the actual time spent in compressed air. Decompression is carried out based on the sum of the actual exposure time and the time from table 5 for the pressure encountered.

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.

HISTORY

1. Amendment of Appendix B filed 8-7-85; effective thirtieth day thereafter (Register 85, No. 32).

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