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JICOSH Home > Laws > Ordinance on Safety and Health of Work under High Pressure

Ordinance on Safety and Health of Work under High Pressure

(Revised in terms of the Title March 19, 1977 by Ministry of Labour Ordinance No. 2)
Ministry of Labour Ordinance No. 40, September 30, 1972
Latest Amendments:
Ministry of Labour Ordinance No. 41 of October 31, 2000

In Japanese

Attached Table 2

Pressure(MPa) Diving depth (m) Duration of work under High pressure
(or in compressed air)		 Pressure reducing 
(or decompression) rate (min.)		 Body (internal) gas pressure coefficient Pressure reducing (or decompression) time (min.) between works Pressure reducing (or decompression) time (min.) after work Duration(min.)
of work under
high pressure
(or in compressed air
per day)
0.24 0.21 0.18 0.15 0.12 0.09 0.06 0.03
MPa MPa MPa MPa MPa MPa MPa MPa
Duration of diving Surfacing (min.) Duration
(min.) of
diving per
day  
24m 21m 18m 15m 12m 9m 6m 3m
0.10 or more and not more than 0.12  10 or more and not more than 12 Not more than 10 minutes







1.1 30 30 480
10 min. or more and not more than 30 min.







1.2 30 30
30 min. or more and not more than 60 min.







1.4 30 30
60 min. or more and not more than 90 min.







1.5 30 30
90 min. or more and not more than 120 min.







1.6 30 30
120 min. or more and not more than 180 min.






3 1.8 60 30
180 min. or more and not more than 240 min.






5 1.9 60 30
240 min. or more and not more than 360 min.






7 2.1 150 60
0.12 or more and not more than 0.14 12 or more and not more than 14 Not more than 10 minutes







1.1 30 30 420
10 min. or more and not more than 30 min.







1.3 30 30
30 min. or more and not more than 60 min.







1.5 30 30
60 min. or more and not more than 90 min.







1.6 30 30
90 min. or more and not more than 120 min.






4 1.7 60 30
120 min. or more and not more than 150 min.






6 1.8 60 30
150 min. or more and not more than 180 min.






7 1.9 60 30
180 min. or more and not more than 210 min.






9 2.0 60 30
210 min. or more and not more than 240 min.






10 2.0 150 60
240 min. or more and not more than 300 min.






12 2.1 150 60
0.14 or more and not more than 0.16 14 or more and not more than 16 Not more than 10 minutes







1.1 30 30 360
10 min. or more and not more than 30 min.







1.3 30 30
30 min. or more and not more than 50 min.







1.4 30 30
50 min. or more and not more than 70 min.







1.6 30 30
70 min. or more and not more than 90 min.






3 1.7 60 30
90 min. or more and not more than 120 min.






6 1.8 60 30
120 min. or more and not more than 150 min.






9 1.9 60 30
150 min. or more and not more than 180 min.






12 2.0 60 30
180 min. or more and not more than 210 min.






13 2.1 150 60
210 min. or more and not more than 270 min.






17 2.2 150 60
0.16 or more and not more than 0.18 16 or more and not more than 18 Not more than 10 minutes







1.1 30 30 300
10 min. or more and not more than 25 min.







1.3 30 30
25 min. or more and not more than 40 min.







1.4 30 30
40 min. or more and not more than 55 min.







1.5 30 30
55 min. or more and not more than 75 min.






2 1.7 60 30
75 min. or more and not more than 105 min.






11 1.8 60 30
105 min. or more and not more than 135 min.






16 1.9 60 30
135 min. or more and not more than 150 min.





4 16 2.0 60 30
150 min. or more and not more than 180 min.





7 16 2.1 150 60
180 min. or more and not more than 240 min.





9 21 2.2 150 60
0.18 or more and not more than 0.20 18 or more and not more than 20 Not more than 10 minutes







1.2 30 30 270
10 min. or more and not more than 25 min.







1.3 30 30
25 min. or more and not more than 35 min.







1.4 30 30
35 min. or more and not more than 50 min.







1.5 30 30
50 min. or more and not more than 65 min.






9 1.6 30 30
65 min. or more and not more than 95 min.






16 1.8 60 30
95 min. or more and not more than 115 min.





7 16 1.9 60 30
115 min. or more and not more than 135 min.





10 16 2.0 60 30
135 min. or more and not more than 165 min.





15 27 2.1 150 60
165 min. or more and not more than 225 min.





18 34 2.2 150 60
0.20 or more and not more than 0.22 20 or more and not more than 22 Not more than 15 minutes







1.2 30 30 240
15 min. or more and not more than 30 min.







1.4 30 30
30 min. or more and not more than 42 min.







1.5 30 30
42 min. or more and not more than 60 min.






7 1.7 60 30
60 min. or more and not more than 75 min.






16 1.8 60 30
75 min. or more and not more than 85 min.





5 16 1.8 60 30
85 min. or more and not more than 100 min.





12 16 1.9 60 30
100 min. or more and not more than 120 min.





17 22 2.0 60 30
120 min. or more and not more than 150 min.





21 29 2.1 150 60
150 min. or more and not more than 210 min.





25 39 2.2 150 60
0.22 or more and not more than 0.24 22 or more and not more than 24 Not more than 10 minutes







1.2 30 30 216
10 min. or more and not more than 25 min.







1.4 30 30
25 min. or more and not more than 37 min.







1.5 30 30
37 min. or more and not more than 50 min.






6 1.6 30 30
50 min. or more and not more than 58 min.






14 1.7 60 30
58 min. or more and not more than 75 min.





16 14 1.8 60 30
75 min. or more and not more than 90 min.





18 16 1.9 60 30
90 min. or more and not more than 108 min.





21 22 2.0 90 30
108 min. or more and not more than 145 min.





27 32 2.1 150 60
145 min. or more and not more than 180 min.





29 41 2.2 150 60
0.24 or more and not more than 0.25 24 or more and not more than 26 Not more than 10 minutes







1.2 30 30 200
10 min. or more and not more than 20 min.







1.3 30 30
20 min. or more and not more than 32 min.







1.5 30 30
32 min. or more and not more than 45 min.






7 1.6 30 30
45 min. or more and not more than 55 min.






16 1.7 60 30
55 min. or more and not more than 65 min.




8 16 1.8 60 30
65 min. or more and not more than 80 min.





18 16 1.9 60 30
80 min. or more and not more than 100 min.





26 22 2.0 90 30
100 min. or more and not more than 110 min.





27 25 2.0 150 60
110 min. or more and not more than 160 min.





29 41 2.2 150 60
0.25 or more and not more than 0.27 26 or more and not more than 28 Not more than 10 minutes







1.2 30 30 180
10 min. or more and not more than 20 min.







1.4 30 30
20 min. or more and not more than 28 min.







1.5 30 30
28 min. or more and not more than 40 min.






6 1.6 30 30
40 min. or more and not more than 44 min.






11 1.6 30 30
44 min. or more and not more than 49 min.






16 1.7 60 30
49 min. or more and not more than 60 min.





11 16 1.8 60 30
60 min. or more and not more than 70 min.





18 22 1.9 60 30
70 min. or more and not more than 90 min.





27 22 2.0 90 30
90 min. or more and not more than 110 min.




8 27 29 2.1 150 60
110 min. or more and not more than 140 min.




13 29 41 2.2 150 60
0.27 or more and not more than 0.29 28 or more and not more than 30 Not more than 10 minutes







1.2 30 30 170
10 min. or more and not more than 20 min.







1.4 30 30
20 min. or more and not more than 25 min.







1.5 30 30
25 min. or more and not more than 35 min.






4 1.6 30 30
35 min. or more and not more than 39 min.






10 1.6 30 30
39 min. or more and not more than 44 min.






16 1.7 60 30
44 min. or more and not more than 50 min.





8 16 1.8 60 30
50 min. or more and not more than 60 min.





16 16 1.8 60 30
60 min. or more and not more than 78 min.





27 22 1.9 60 30
78 min. or more and not more than 85 min.




5 27 22 2.0 90 30
85 min. or more and not more than 105 min.




12 27 32 2.1 150 60
105 min. or more and not more than 130 min.




17 29 48 2.2 150 60
0.29 or more and not more than 0.31 30 or more and not more than 32 Not more than 10 minutes







1.2 30 30 158
10 min. or more and not more than 22 min.







1.4 30 30
22 min. or more and not more than 30 min.






8 1.5 30 30
30 min. or more and not more than 35 min.






14 1.6 30 30
35 min. or more and not more than 40 min.






22 1.6 30 30
40 min. or more and not more than 46 min.





9 22 1.7 60 45
46 min. or more and not more than 53 min.





16 22 1.8 60 45
53 min. or more and not more than 68 min.





27 22 2.0 90 45
68 min. or more and not more than 79 min.




7 27 33 2.0 90 45
79 min. or more and not more than 100 min.




17 27 48 2.1 150 60
100 min. or more and not more than 120 min.




21 27 55 2.1 150 60
0.31 or more and not more than 0.33 32 or more and not more than 34 Not more than 10 minutes







1.2 60 30 146
10 min. or more and not more than 19 min.







1.4 60 30
19 min. or more and not more than 27 min.






7 1.5 60 30
27 min. or more and not more than 31 min.






22 1.6 60 30
31 min. or more and not more than 36 min.






22 1.7 90 45
36 min. or more and not more than 41 min.





8 22 1.7 90 54
41 min. or more and not more than 48 min.





16 22 1.8 90 45
48 min. or more and not more than 60 min.





27 22 1.9 90 45
60 min. or more and not more than 73 min.




10 27 37 2.0 120 45
73 min. or more and not more than 95 min.




19 27 63 2.0 150 60
95 min. or more and not more than 115 min.



5 22 32 74 2.0 150 60
0.33 or more and not more than 0.35 34 or more and not more than 36 Not more than 5 minutes







1.2 60 30 134
5 min. or more and not more than 17 min.







1.4 60 30
17 min. or more and not more than 25 min.






8 1.5 60 30
25 min. or more and not more than 29 min.






14 1.6 60 30
29 min. or more and not more than 33 min.






22 1.6 60 30
33 min. or more and not more than 38 min.





9 22 1.7 90 45
38 min. or more and not more than 43 min.





16 22 1.8 90 45
43 min. or more and not more than 55 min.





27 22 1.9 90 45
55 min. or more and not more than 67 min.




10 27 34 2.0 120 45
67 min. or more and not more than 90 min.




22 27 63 2.0 150 60
90 min. or more and not more than 110 min.



9 22 34 80 2.0 150 60
0.35 or more and not more than 0.37 36 or more and not more than 38 Not more than 5 minutes







1.2 30 60 124
5 min. or more and not more than 15 min.







1.4 30 60
15 min. or more and not more than 22 min.






5 1.5 30 60
22 min. or more and not more than 26 min.






14 1.6 30 60
26 min. or more and not more than 30 min.






22 1.6 30 60
30 min. or more and not more than 34 min.





9 22 1.7 45 90
34 min. or more and not more than 40 min.





17 22 1.8 45 90
40 min. or more and not more than 50 min.





27 22 1.9 45 90
50 min. or more and not more than 62 min.




12 27 34 2.0 45 120
62 min. or more and not more than 85 min.



4 22 27 67 2.0 60 150
85 min. or more and not more than 105 min.



12 22 36 83 2.0 60 150
0.37 or more and not more than 0.39 38 or more and not more than 40 Not more than 5 minutes







1.2 60 30 116
5 min. or more and not more than 15 min.







1.4 60 30
15 min. or more and not more than 20 min.






3 1.5 60 30
20 min. or more and not more than 24 min.






14 1.6 60 30
24 min. or more and not more than 28 min.






22 1.6 60 30
28 min. or more and not more than 32 min.





9 22 1.7 90 45
32 min. or more and not more than 37 min.





18 22 1.8 90 45
37 min. or more and not more than 46 min.





27 22 1.9 90 45
46 min. or more and not more than 58 min.




14 27 28 2.0 120 45
58 min. or more and not more than 80 min.



6 22 27 68 2.0 150 60
80 min. or more and not more than 100 min.



16 22 36 82 2.0 150 60
0.39 or more and not more than 0.41 40 or more and not more than 42 Not more than 13 minutes






2 1.4 60 30 110
13 min. or more and not more than 16 min.






4 1.4 60 30
16 min. or more and not more than 21 min.






11 1.5 60 30
21 min. or more and not more than 26 min.






22 1.6 60 30
26 min. or more and not more than 29 min.





9 22 1.7 90 45
29 min. or more and not more than 35 min.





14 22 1.8 90 45
35 min. or more and not more than 42 min.





27 28 1.8 90 45
42 min. or more and not more than 55 min.




15 27 34 2.0 120 45
55 min. or more and not more than 75 min.



8 22 27 65 1.9 150 60
75 min. or more and not more than 95 min.



16 22 36 80 2.0 150 60
0.41 or more and not more than 044 42 or more and not more than 45 Not more than 10 minutes






2 1.4 60 30 100
10 min. or more and not more than 14 min.






8 1.4 60 30
14 min. or more and not more than 20 min.






14 1.6 60 30
20 min. or more and not more than 24 min.






22 1.6 60 30
24 min. or more and not more than 30 min.





15 28 1.6 60 30
30 min. or more and not more than 37 min.





27 28 1.8 60 45
37 min. or more and not more than 50 min.




16 27 34 2.0 120 45
50 min. or more and not more than 70 min.



11 22 27 68 2.0 150 60
70 min. or more and not more than 90 min.


4 19 22 30 107 2.0 150 60
0.44 or more and not more than 0.49 42 or more and not more than 45 Not more than 8 minutes






2 1.3 60 30 86
8 min. or more and not more than 12 min.






8 1.4 60 30
12 min. or more and not more than 16 min.






16 1.5 60 30
16 min. or more and not more than 20 min.






28 1.6 60 30
20 min. or more and not more than 26 min.





16 28 1.7 90 45
26 min. or more and not more than 33 min.





27 28 1.8 90 45
33 min. or more and not more than 43 min.




18 27 31 2.0 120 45
43 min. or more and not more than 60 min.



13 23 27 68 2.0 150 60
60 min. or more and not more than 80 min.


9 19 22 45 85 2.0 150 60
0.49 or more and not more than 0.54 50 or more and not more than 55 Not more than 6 minutes






2 1.3 60 30 75
6 min. or more and not more than 10 min.






7 1.4 60 30
10 min. or more and not more than 12 min.






17 1.5 60 30
12 min. or more and not more than 14 min.






27 1.5 60 30
14 min. or more and not more than 17 min.






36 1.6 60 30
17 min. or more and not more than 21 min.





14 36 1.7 90 45
21 min. or more and not more than 27 min.





27 36 1.8 90 45
27 min. or more and not more than 37 min.




18 27 44 1.9 90 45
37 min. or more and not more than 55 min.

6 20 24 28 65 65 1.9 150 60
55 min. or more and not more than 75 min.55 min. or more and not more than 75 min.  
8 18 20 24 49 90 73 1.9 150 60
0.54 or more and not more than 0.59 55 or more and not more than 60 Not more than 5 minutes






2 1.3 60 30 70
5 min. or more and not more than 10 min.






16 1.5 60 30
10 min. or more and not more than 15 min.






36 1.5 60 30
15 min. or more and not more than 24 min.





23 36 1.8 90 45
24 min. or more and not more than 33 min.




16 27 42 1.9 90 45
33 min. or more and not more than 50 min.

9 20 24 27 65 70 1.9 150 60
50 min. or more and not more than 70 min.
14 18 20 24 50 100 73 1.9 150 60
0.59 or more and not more than 0.64 60 or more and not more than 65 Not more than 5 minutes






5 1.3 60 30 65
5 min. or more and not more than 12 min.






32 1.5 60 30
12 min. or more and not more than 21 min.





23 36 1.8 90 45
21 min. or more and not more than 30 min.


2 24 28 35 45 1.9 90 45
30 min. or more and not more than 45 min.

6 20 24 28 56 73 1.9 150 60
45 min. or more and not more than 65 min. 4 16 18 20 26 53 92 73 1.9 150 60
0.64 or more and not more than 0.69 65 or more and not more than 70 Not more than 5 minutes






10 1.4 60 30 60
5 min. or more and not more than 11 min.






34 1.5 60 30
11 min. or more and not more than 18 min.





25 36 1.7 90 45
18 min. or more and not more than 27 min.


4 24 28 35 45 1.9 90 45
27 min. or more and not more than 40 min.

12 20 24 28 65 95 1.8 150 60
40 min. or more and not more than 60 min. 8 16 17 20 27 52 95 105 1.8 150 60
0.69 or more and not more than 0.78 70 or more and not more than 80 Not more than 5 minutes






1 6 1.5 60 30 50
5 min. or more and not more than 10 min.





8 35 1.6 60 30
10 min. or more and not more than 15 min.





28 35 1.7 90 45
15 min. or more and not more than 22 min.


7 24 28 37 51 1.8 90 45
22 min. or more and not more than 35 min.

18 20 24 30 65 100 1.8 150 60
35 min. or more and not more than 50 min. 12 16 18 20 28 52 95 105 1.8 150 60
0.78 or more and not more than 0.88 80 or more and not more than 90 Not more than 5 minutes






30 1.5 60 30 40
5 min. or more and not more than 10 min.





20 35 1.7 90 45
10 min. or more and not more than 15 min.




14 28 35 1.8 90 45
15 min. or more and not more than 20 min.


13 24 28 44 51 1.9 90 45
20 min. or more and not more than 30 min.
6 18 20 24 29 65 100 1.8 150 60
30 min. or more and not more than 40 min. 12 16 18 20 24 49 90 100 1.8 150 60

INDEX
I / II / III / IV / V / VI
Table1 / Table2 / Table3
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