Ordinance on Safety and Health of Work under High Pressure

Chapter III.  Management of Work

Section 1.  Operations Chiefs, etc.

(Operations Chief)

Article 10. In terms of the work in compressed air in compliance with item 1 of Article 6 of the Cabinet Order, the employer shall appoint one operations chief responsible for each work chamber, out of those who are licensed as operations chiefs of work in compressed air.

2.  The employer shall make the said operations chief carry out the matters given below:

(1)  Make a decision on how to carry out the work, and supervise directly the compressed air workers.

(2)  Check the devices used to measure the concentrations of carbon dioxide and harmful gases (which correspond to carbon monoxide, methane, hydrogen sulfide, and other gases other than carbon monoxide, which may induce explosion, fire, other dangerous situations, or damage to health, similarly as in the following).

(3)  Check the number of compressed air workers, when the workers are made to enter or leave the work chamber room for the said work.

(4)  Maintain the pressure within the work chamber in a proper state by contacting those who engage in the work there to operate valves or cocks by which to regulate the volumes of the air fed to the said work chamber.

(5)  Assume appropriate measures thereby to apply compression or decompression to the compressed air workers, in compliance with the provisions of Article 14 or Article 18 by contacting those who are engaged in the work thereby to operate valves or cocks to regulate the air fed to or exhausted from the man-lock.

(6)  To assume necessary measures in case the compressed air workers should become health impairment in the work chamber or the man-lock.

(Special Education)

Article 11. When the employer has workers engage in the work as described below, the employer shall give the said workers special education concerning the said work:

(1)  Operating the air compressor by which air is fed to a work chamber or to a man-lock.

(2)  Operating the valves or cocks by which to regulate the air supplied to the work chamber.

(3)  Operating the valves or cocks by which to regulate the air fed to or exhausted from the man-lock.

(4)  Operating the valves or cocks which regulate the air fed to the diving workers.

(5)  Operating the recompressing lock.

(6)  Work in compressed air.

2.  The education as said above shall be carried out in terms of the items given in the right columns of the Table below, depending upon the type of work as shown in the left column of the said Table.

3.  In addition to these items, as provided for in Articles 37 and 38 of the Ordinance on Industrial Safety and Health (Ministry of Labour Ordinance No. 32 of 1972, and hereinafter called "Safety and Health Ordinance"), as well as the ones as described in the preceding two paragraphs, the Minister of Health, Labour and Welfare will establish items necessary for the execution of the special education prescribed in the same paragraph.

(Diving Workers)

Article 12. The employer shall not have any person engage in diving operations unless he has been licensed as a diving worker.

Section 2.  Management of Work in Compressed Air

(Prohibition of Entrance into Work Areas)

Article 13. The employer shall prohibit those other than persons directly concerned from entering the man-lock and work chamber, and shall put up a notice which can easily be identified outside the caissons, diving bells, compressed shields, etc., stating the prohibition.

(Rate of Compression)

Article 14. When the employer applies compression to the compressed air workers in a man-lock, the employer shall increase the pressure at a rate not higher than 0.08 MPa/min.

(Time Spent under High Pressure)

Article 15. When the employer has workers engage in work in compressed air, (restricted only to those types carried out under barometric pressures of 0.1 MPa or more, same as in this Article), the employer shall not make the compressed air workers engage in the said work in compressed air in violation of the standards on time given below for which the said workers are allowed to engage in the said work.

(1)  The time, starting off from commencing the compression on the compressed air workers till commencing the decompression on them, (hereinafter called the "time spent under high pressure") shall be limited as set forth in the following (a) or (b).

a  In case the numbers of shifts of work in which the employer has the compressed air workers engage in the said work in compressed air does not exceed twice per day and in addition the pressure imposed on the said workers does not exceed 0.4 MPa, the times given below are allowable:

(a)  In terms of the first shift of work in compressed air (inclusive of the case in which the work in compressed air is carried out once per day); the longest time of those listed in the "Time under high pressure" column of Attached Table 1 depending upon the division of the "Pressure" column of the said Table, on the basis of the pressures used for the said work in compressed air.

(b) In terms of the second shift of work in compressed air; the time as listed in the "Time under high pressure for the second shift" column of Attached Table 1 depending upon the direction of the "Pressure" column of the said Table and the "Time under high pressure" column of the said Table in accordance with the time under high pressure used for the first shift, on the basis of the pressure used for the said work in compressed air (which corresponds to the one used for the first shift, if the pressure used for the first shift is higher than that for the second shift).

b  In case the number of shifts of work in compressed air conducted by compressed air worker exceeds two per day or the pressure used for the work in compressed air exceeds 0.4 MPa , the times allowable are given below:

(a)  In the terms of the first shift of work in compressed air (inclusive of the case in which the work in compressed air is carried out once per day); the longest time of those listed in the "Time under high pressure" column depending the classification of the "Pressure" column of Attached Table 2 on the basis of the pressures used for the said work in compressed air. 

(b) In terms of the second or following shift of work in compressed air; the time which is subtracted from the time which is obtained from Attached Table 3 (hereinafter called "corrected time for compressed air workers") from the longest time of those listed in the "Time under high pressure" column of Attached Table 2 depending upon the division of the "Pressure" column of the said Table on the basis of the pressure used for the said shift of work in compressed air (maximum pressure, in the case in which the pressure used for the work in compressed air already done by the said workers in the day is higher than that used for the said work in compressed air) (when a total of time, during work in compressed air is longer than the time set forth in the "Time under high pressure per day" column in accordance with the classification of the pressures as listed in the "Pressure" column of Attached Table 2 on the basis of the maximum pressure used for work in compressed air, and imposed on the said workers, the time is available by further subtraction of the differences between the said total of the time and those set forth in the "Time under high pressure" column from the said longest of time of those described in the "Time under high pressure" column). 

(2)  When the employer has compressed air workers who have already engaged in work in compressed air further engage in the said work within a day, the employer shall provide the compressed air workers with a time, upon the completion of last decreasing gas pressures, which is longer than those set forth in the following (a) or (b), as the time for which to make decrease in the gas coefficients in the body of the compressed air workers (hereinafter called "time for decompression for the compressed air workers), and shall not make the compressed air workers further engage in heavy work for the said time.

a) When there occurs a case which corresponds to that set forth in (a) of the preceding item; the time as listed in the "Time for decreasing gas pressure between shifts of work in compressed air" column of Attached Table 1 in accordance with the classification set forth in the "Pressure" column and also in the "Time under high pressure" column of the said Table on the basis of the pressure and the time under high pressure used for the first shift of work in compressed air.

b) When there occurs a case as set forth in (b) of the preceding item; the time as listed in the "Time for decreasing gas pressure between shifts of work in compressed air" column of Attached Table 2 in accordance with the classification set forth in the "Pressures" column and also in the "Time under high pressure", column of the said Table on the basis of the pressure and the time under high pressure used for the final shift of work in compressed air.

(3)  When the employer shall provide compressed air workers who have completed the work in compressed air for that day with the time, upon the completion of last decompression, which are longer than those set forth in the following a or b, as the time for decreasing gas pressures for the compressed air workers, and shall not make the compressed air workers further engage in heavy work.

a) When there occurs a case which corresponds to those set forth in (a) of item 1; the time as listed in "Time for decreasing gas pressure after completion of work" column of Attached Table 1 in accordance with the classification set forth in the "Pressures" column and also in the "Time under high pressures" of the said Table on the basis of the pressure and the time under high pressure used for the final shift of work in compressed air.

b) When there occurs a case set forth in (b) of item 1; the time as listed in the "Time for decreasing gas pressures after completion of work" column of Attached Table 2 in accordance with the classification set forth in the "Pressure" column and also in the "Time under high pressures" column of the said Table on the basis of the pressure and the time under high pressure used for the final shift of work in compressed air.

(4)  In a case in which the employer gives the time for decreasing gas pressure of compressed air workers following the second time to the workers who work two shifts or more in compressed air per day, the times under high pressure of work in compressed air set forth in (a) of item 2 and (a) and (b) of the preceding item shall be those which are available by the addition of the time under high pressure used for the said shift of the compressed air workers concerned and the corrected time for compressed air workers.

(Control of Carbon Dioxide)

Article 16. The employer shall make ventilation and assume other required measures to ensure that the partial pressure of carbon dioxide is not more than 0.5 kPa in the work chamber or man-lock in order to prevent the hazards due to carbon dioxide.

(Control of Harmful Gases)

Article 17. The employer shall make ventilation, measure harmful gases and assume other required measures thereby to prevent danger and health impairment to workers due to harmful gases in the work chamber.

(Rate of Decompression)

Article 18. When the employer reduces the pressure imposed on the compressed air workers in the man-lock, he shall comply with the items given below:

(1)  The rate of decompression shall be 0.08 Mpa/min or less.

(2)  When there occurs a case as described in (a) of item 1 of Article 15, the employer shall stop the decompression for the time set forth in the "Decompression" column or more, when the said pressure reaches that as described in the "Decompression" column in accordance with the classification as made in the "Pressure" column and the "Time under high pressures" column of Attached Table 1 on the basis of the pressures and the time under high pressure during the said work in compressed air.

(3)  When there occurs a case as described in (b) of item 1 of Article 15, the employer shall stop the decompression for the period of time set forth in the "Decompression" column or more, when the said pressure reaches that set forth in the "Decompression" column in accordance with the classification as made in the "Pressure" column and "Time under high pressure" column of Attached Table 2 on the basis of the pressures and time under high pressure during the said work in compressed air.

2.  The provision of item 4 of Article 15 shall apply correspondingly in respect to the time under high pressures set forth in items 2 or 3 of the preceding Article, in the case of applying decompression for the second or subsequent time to a compressed air worker who is working more than two shifts of work in compressed air per day.

(Exceptions to Provisions on Decompression)

Article 19. When the employer has a compressed air worker evacuate in an accident or rescues a compressed air worker who has become impaired in health, the employer is allowed to increase the rate of decompression as provided for by the preceding Article or to reduce the time for stopping decompression as also provided for by the same Article within the limits of minimum necessity.

2.  When the employer increases the rates of decompression or reduces the time for stopping the decompression in compliance with the provisions of the preceding paragraph, the employer shall quickly make the said worker enter into a recompression lock or man-lock after he has made the said worker evacuate or be rescued, and shall increase the pressure imposed on the said worker up to that which corresponds to the pressure used for the said shift of work in compressed air.

3. The provision of Article 14 shall apply correspondingly in respect to the rate at which to increase the pressures when applying compression to the worker according to the provisions of the preceding paragraph.

(Measures Assumed when Applying Decompression)

Article 20. When the employer carries out decompression on a compressed air worker in a man-lock, he shall assume each of the measures given below:

(1)  The illuminance at the surface of the floor shall not be less than 20 lux.

(2)  In case the temperature in the man-lock is 10ºC or less, the employer shall have the compressed air worker use blankets or other proper warming devices.

(3)  In the case the time required for decompression is longer than an hour, the employer shall have the compressed air worker use a chair or other reposing article.

2.  When applying decompression to a compressed air worker in a man-lock, the employer shall inform in advance the said compressed air worker of the time necessary for decompression concerned.

(Recording, etc., for Decompression Status)

Article 20-2. When the employer shall have compressed air workers engage in work in compressed air under a barometric pressure of 0.1 MPa or more, the employer shall provide the man-lock with a self-recording pressure gauge, and shall prepare documents in which to record the status concerning each decompression and also documents in which to fill in names of the said compressed air workers and dates of decompression, for every time when applying decompression to a compressed air worker in the man-lock. And he shall keep these documents in custody for the period of five years.

(Communication)

Article 21. When the employer has compressed air workers engage in work in compressed air, he shall always station a liaison for contacting with the compressed air workers or with those who operate the air compressor, and also those responsible for other required measures (hereinafter called "liaison" in this Article).

2.  The employer shall provide for communicating devices by which the said liaison can communicate with the compressed air workers and those who operate the air compressor.

3.  The employer shall establish methods by which communication can be effected, even if the said devices break down, as provided for by the preceding Article, and shall put up a notice which indicates the methods at a conspicuous place from which the written methods can easily be seen by the compressed air workers, air compressor operators, and the said liaison.

(Inspection and Repairing of Equipment)

Article 22. When the employer has a compressed air worker engage in work in compressed air, he shall make an inspection of the equipment, given in the following items, at least once at every period as described in the respective items, and shall make repairs and also assume other required measures when he finds probable hazards or health impairments to the compressed air worker:

(1)  Air pipelines as described in Article 4, air exhaust pipelines set forth in Article 6 and the communicating devices as described in paragraph 2 of the preceding Article: one day.

(2)  Valves or cocks regulating the feeding of air to the work chamber or the man-lock: one day.

(3)  Valves or cocks regulating the exhausting of air from the work chamber or the man-lock: one day.

(4)  Cooling devices attached to the air compressor for feeding of air to the work chamber or to the man-lock: one day.

(5)  The devices described in Article 7-4: one day.

(6)  Automatic warning devices described in Article 7-2: one week.

(7)  The air compressor for feeding air to the work chamber or to the man-lock: one week.

(8)  Pressure gauges described in Article 7 and Article 26: one month.

(9)  Equipment for cleaning the air as set forth in the Article 5: one month.

(10) Electrical circuits installed in the caissons, diving bells, compressed shields, etc.: one month.

2.  When the employer makes an inspection of the devices, etc., in compliance with the provisions set forth in the preceding paragraph, provides for the repairing of them, and assumes other required measures, the employer shall record the results concerning the inspection, repairing and the other measures, as soon as they have been completed, and shall keep a short description of the record in custody for the period of three years.

(Inspection when the Air-Feeding Equipment Is Started)

Article 22-2. When the employer first uses air feeding equipment, when the employer disassembles and improves or repairs the said equipment or when the employer reuses the said air feeding equipment which has not been used for more than one month, he shall make an inspection of the performance of the said air feeding equipment and confirm that there is no abnormality in its performance before resuming its use.

(Measures to Be Taken in the Case of Accident)

Article 23. When there is a possibility that hazards or health impairment to compressed air workers may have occurred due to a breakdown of the air feeding equipment, a flood, etc., the employer shall have the compressed air workers evacuate the caissons, diving bells, compressed shields, etc. 

2.  In a case set forth in the preceding paragraph, the employer shall make inspection of the presence or absence of abnormalities in the air-feeding equipment, the presence or absence of abnormal sinking of the diving bell, etc., the slanted status of the said devices and other items, and shall confirm that there is no possibility that hazard or health impairment may occur to the compressed air workers. He shall not have workers other than those who are specifically designated by the employer enter into the said caissons, diving bells, compressed shields, etc., until the said inspection and confirmation have been carried out by him.

(Measures Assumed for Submerging Exhausted Caissons)

Article 24. When the employer submerges the said caissons by exhausting the air from the work chamber, he shall make the compressed air workers leave the caissons.

2.  In a case as described in the preceding paragraph, the employer shall make inspection of the presence or absence of flooding or generation of harmful gases, and also of the other items, and shall confirm that there is no possibility that there may occura hazard or health impairment to the compressed air workers. And the employer stall not have workers other than those who are specifically designated by him enter into the caissons until he has confirmed there is no possibility concerning the said hazard or health impairment.

(Measures Assumed in a Case in which Blasting is Carried Out)

Article 25. When the employer carry out blasting in the work chamber, he shall not make the compressed air workers enter into the work chamber till the air has returned to its original condition before the blasting.

(Prevention of Burns, etc.)

Article 25-2. When the employer has a compressed air worker carry out work in compressed air, he shall inform the compressed air worker of the danger of combustion of substances combustible under pressures higher than atmospheric pressure, and shall furthermore assume the measures given below in terms of the caissons, diving bells, compressed shields, etc., in order to prevent burns and other danger from affecting the compressed air worker:

(1)  The employer shall use lighting devices (lamps) with guards and other lamps in which there is no possibility that ignition will be made to combustible substances resulting from breakdown of the said lamps.

(2)  In terms of switching devices used in electrical circuits, the employer shall use those from which no sparks or arc can occur.

(3)  In terms of heating devices, the employer shall use those which have no possibility that they may serve as an ignition source for combustible substances when temperatures become high.

2.  When the employer has a compressed air worker engage in work in compressed air, he shall not have the said worker carry out work such as welding, cutting, and other work using either fire or arc (hereinafter called "work of welding, etc.") inside the caissons, diving bells, compressed shields, etc., provided that this does not apply in respect to the cases which are hardly avoidable owing to the nature of the work, and in which the work such as welding, etc., is carried out under pressures of less than 0.1 MPa .

3. When the employer has a compressed air worker carry out work in compressed air, he shall prohibit the said worker from taking with him fire, matches, lighters, or other goods which give cause to fear that ignition or combustion may occur to enter into the caissons, diving bells, compressed shields, etc., and shall also put up a notice which describes the said prohibition as stated above at a conspicuous place outside of the man-lock, provided that this does not apply in respect to cases which are hardly avoidable owing to the nature of work and in which he is allowed to make the compressed air worker take with him fire, matches, lighter, or other possible ignitable or combustible goods which are necessary for carrying out the said work of welding, etc., which are carried out under pressures of less than 0.1 MPa, to enter into the inside of the said caisson, diving bell, compressed shield, etc.

(Limits concerning Digging Down below the Edge)

Article 25-3. The employer shall not have a compressed air worker dig down the portion below the edge of a caisson in depths or 50 cm or more in order to prevent hazard to the compressed air worker resulting from the sudden submerging of the caisson.

(Devices which Are Carried by Operations Chief of Work in Compressed Air)

Article 26. The employer shall have the operations chief of work in compressed air take with him a portable pressure gauge, flashlight, gas measuring apparatus to measure the concentrations of carbon dioxide and other harmful gases, and also signaling devices for an emergency.

Section 3.  Management of Diving Operations

(Time Spent under Water)

Article 27. When the employer has workers engage in diving operations (restricted only to those done at a depth of 10 m or more, same as in this Article), he shall not have the diving workers engage in such a operations in violation of the periods as provided by the provisions given below:

(1)  The time spent from when the diving workers start descending until they commence ascending (hereinafter called "time spent under water") shall be limited to the values given below:

a  In terms of the first shift of diving operations (inclusive of that carried out once per day); the longest time among the times listed in the "Time spend under water" column of Attached Table 2 in accordance with the classification as made in the "Diving depth" column of the said Table on the basis of the depth in which the said shift of diving operation is carried out.

b  In terms of the second or subsequent shift of diving operation; the times which are available to the reduction of numeric values as noted in the "Gas pressure coefficient in body" column of Attached Table 2 depending upon the classification as made in the "Diving depth" column and the "Time spent under water" column of the said Table on the bases of the diving depth and the time spent under water as used for the previous diving operation, time therefore to decrease gas pressure in the said diving workers as described in item 3 to 5, and the time, as obtainable from Attached Table 3, (hereinafter called "corrected time for diving workers") from the longest of the times listed in the "Time spent under water" column of Attached Table 2 depending upon the classification as made in the "Diving depth" column of the said Table on the basis of the said diving depth, in which the said diving operation is carried out, (corresponding to the one which is deepest, if the diving depth in which the said diving workers operated on the previous shift of diving operations within a day is deeper than that in which the said second or subsequent diving operation has been carried out on the day.) (When the total time for which the said diving workers engaged in diving operations within a day are longer than the time as noted in the "Time spent under water for one day" column of Attached Table 2, depending upon the classification as made in the "Diving depth" column of the said Table on the basis of the deepest depth in which the said diving workers engaged in diving operation on the day, the time is available by further reduction of the difference between the total times and the said times as described in the "Time spent under water for one day" column from the said longest time of those described in the "Time spent under water" column).

(2)  When the employer has the diving workers engage in diving operations in more than three shifts per day, and when he makes them engage in the third or subsequent shift of diving operation within a day, the time spent under water for the previous shift in compliance with the provisions of b of the preceding item shall be that which is available by the addition of the time spent under water for the said shift of diving operations and the corrected time for diving workers as mentioned before.

(3)  When the employer has diving workers who have already engaged in diving operations on a day, further engage in diving operations on that day, he shall give the said diving workers times which are longer than those listed in the "Time for decreasing gas pressure between shifts" column of Attached Table 2, depending upon the classification as made in the "Diving depth" column and the "Time spent under water" column of the said Table on the basis of the diving depth and time spent under water used for the immediately previous shift of diving operations carried out within a day in the form of the rest periods of time (hereinafter called "time for decreasing gas pressure of diving workers") in order to decrease the gas pressure coefficient in the bodies of the said diving workers after the said diving workers have gone through the said immediately previous shift of diving operations, and for the rest time, the employer shall not make the said diving workers engage in heavy work.

(4)  The employer shall give diving workers who have gone through all shifts of the diving operations within a day times which are longer than those described in the "Time for decreasing gas pressure after completion of operation" column of Attached Table 2, depending upon the classification as made in the "Diving depth" column and the "Time spent under water" column of the said Table on the basis of the diving depth and time spent under water used for the final shift of diving operations carried out within a day in the form of time for decreasing gas pressure of the said diving workers after the said diving workers have gone through the final ascension, and shall not make the said diving workers engage in other heavy work.

(5)  The provisions of item 2 will apply correspondingly in respect to the time spent under water used for the diving operations as provided for by the preceding two items when the employer gives the said diving workers the second or subsequent shift of time for decreasing gas pressure for diving workers who engage in two shifts or more of diving operations within a day.

(Amounts of Air Feeding and Air Feeding Pressure)

Article 28. When the employer feeds air to the diving workers using air compressors or manual air pumps, the quantities of fed air to each of the diving workers shall be 60 liters or more per minute under the pressure as measured at the diving depth of the said diving operation.

  2. Notwithstanding the preceding articles, when the employer has the diving workers use the pressure regulator, he shall make the said diving workers use air compressors which the quantities of fed air to each diving workers shall be 40 liters or more per minute, and air feeding pressure shall be the value added 0.7 MPa to the pressure of diving depth or more.

(Diving Operations Carried Out with Air Supplied from Air Cylinders)

Article 29. When the employer has diving workers supplied with air from air cylinders, which the said diving workers take with them, (exclusive of the ones for an emergency, same as in Articles 34, 36, and 37), he shall assume the measures given below:

(1)  Inform the said diving workers of the existing air-supplying capacity of the air cylinder used for the said diving operation just before the said diving workers start descending.

(2)  Station one who observes whether there any mishaps occur with the said diving workers.

(Pressure Regulator)

Article 30. When the employer has the said diving workers receive air from an air cylinder which contains air under a pressure of 1 MPa or more, he shall make the said diving workers use a pressure regulator using a two-step or more decompression system.

(Rates of Ascending, etc.)

Article 31. When the employer has the said diving workers ascend, he shall comply with the provisions given below:

(1)  The rates of ascending shall be 10 m/min or less.

(2)  When the diving depth reaches that as noted in the "Ascending" column of Attached Table 2, depending upon the classification as made in the "Diving depth" column and the "Time spent under water" column of the said Table on the basis of the diving depth and diving periods of time in or for which the diving operation is carried out at the depth of 10 m or more, he shall stop ascending for a time longer than those described in the said "Ascending" column.

2.  When the employer has the said diving workers engage in diving operations of two shifts or more per day, at the depth of 10 m or more to make the said workers ascend from the locations at which the second or subsequent shift of diving operations within a day was carried out, the provision of item 2 of Article 27 will apply correspondingly in respect to the time spent under water as provided for by item 2 of the preceding paragraph.

(Specific Case of Ascending)

Article 32. When the employer has the said diving workers ascend due to accidents, he is allowed to increase the ascending rates, as provided for by the preceding Article within permitted limits or to reduce the time of stopping ascending, as provided for by the same Article.

2. When the employer increases the rate of ascending, or reduces the time of stopping ascending in compliance with the provisions of the preceding paragraph, he shall make the said diving workers enter into a recompressing lock just after they ascend to the water's surface, and shall apply compression to the diving workers, up to a pressure equal to that at the deepest depth of the location at which the said shift of diving operation was carried out, or make the said workers descend again down to the deepest location at which the said shift of diving operation was carried out.

3. In case the employer has the said diving workers enter into the recompressing lock in compliance with the provisions set forth in the preceding paragraph, the provisions of Article 14 will apply correspondingly in respect to the rates of compression applied to the said diving workers.

(Life Line)

Article 33. When the employer has the said diving workers engage in diving operations, he shall provide a life line and make the said diving workers use it in descending and ascending.

2.  The employer shall provide a life line, as described in the preceding paragraph, with a wooden tag or a piece of cloth which indicates the depth at intervals for the depths as described in the "Ascending" column in Attached Table 2.

(Inspection and Repairing of Equipment)

Article 34. When the employer has the said diving workers engage in diving operations, he shall inspect their equipment, as listed in the respective items given below, in accordance with the diving operations set forth in the said respective items before he makes the said diving workers engage in the said diving operation, and shall make repair of the equipment and also necessary measures when he finds a case in which there may occur danger or health impairment to the said diving workers:

(1)  In terms of the diving operations using an air compressor or manual air pump for air feeding; diving apparatus, air-feeding pipe, signal ropes, life line and also pressure regulator.

(2)  In terms of diving work with an air cylinder (exclusive of an air cylinder which the said diving workers take with them) there from to supply air to the said diving workers; diving apparatus, air feeding pipe, signal ropes, life line or pressure regulator as provided by the Article 30.

(3)  In terms of diving operations with air cylinders which supply air to the said diving workers; diving apparatus and pressure regulator as provided by Article 30.

2.  When the employer has the said diving workers engage in diving operations, he shall make inspection of the equipment as listed in the respective items given below in accordance with the types of diving operations as described in the said respective items at least once at every period given in the said respective items, and shall make repair of the said equipment if defective, and shall assume necessary measures when there may be the possibility of hazards or health impairment to the diving workers may occur:

(1)  In terms of diving operations therein to supply air to the said diving workers, using an air compressor or manual air pump.

a) Air compressor or manual air pump: one week.

b) Air cleaning equipment as provided for by Article 9: one month.

c) Hydro-barometer as provided by Article 37: one month.

d) Hydro-watch as provided by Article 37: three months.

e) Flow-meters as provided by Article 9: six months.

(2)  In terms of diving operations therein to receive air supplied from an air cylinder.

a) Hydro-barometer as provided byArticle 37: one month.

b) Hydro-watch as provided by Article 37: three months.

c) Air cylinder: six months.

3. When the employer makes an inspection of the said equipment or repair of the said equipment or assumes necessary measures in compliance with the preceding two paragraphs, he shall record the results of the inspection or repair when the inspection or repair is carried out, and shall keep a summary record in custody for the period of three years.

(Restrictions on Use of Pure Oxygen)

Article 35. When the employer has diving workers engage in diving operations, he shall not make the said workers inhale pure oxygen.

(Liaison)

Article 36. When the employer has diving workers engage in diving operations with an air compressor or manual air pump thereby to supply air to the said diving workers, or with air cylinders (exclusive of an air cylinder which diving workers might take with them), the employer shall station one liaison (called "liaison" in the following Article) per two diving workers or less to make contact between the said liaison and the diving workers concerned, and shall make the liaison execute the duties given below:

(1) Make contact with the said diving workers to make sure the said divers' descending and ascending are done properly.

(2) Make proper contact with the ones who operate valves or cocks thereby to regulate the air feeding to the said diving workers to supply necessary air to the said diving workers.

(3) Make quick contact with the diving workers when there is a possibility that danger or health impairment of the said diving workers has resulted from accidents involving the damage of air feeding facilities or other accidents.

(4) In terms of diving carried out using the helmet-type diving apparatus, to confirm a sure connection between the said helmets and the pedestal just before a diving worker starts descending.

(Devices to Be Carried by Diving Workers)

Article 37. When the employer has the diving workers engage in diving operations using air compressors or manual air pumps thereby to feed air to the said diving workers, or using air cylinders (exclusive of the ones which the said diving workers take with them) from which the said diving workers receive air to carry out the work, he shall make the said diving workers take with them signal ropes, hydro-watches, hydro-barometers, and sharp-edged knives, provided that the employer is allowed to make the said diving workers refrain from taking with them the said signal ropes, hydro-watches and hydro-barometers when the contact between the said diving workers and liaison can be made through speech communication devices.

2.  When the employer has the diving workers engage in diving operations using air cylinders carried by the said diving workers from which the said diving workers receive the supply of air, he shall make the said diving workers carry with them hydro-watches, hydro-barometers, and sharp-edged knives, and shall make the said diving workers wear a life jacket.