Ordinance on Industrial Safety and Health
Ministry of Labour Ordinance No. 32 of September 30, 1972

Latest Amendments:
Ministry of Health, Labour and Welfare Ordinance No. 47 of March 30, 2007
In Japanese

Section 1 Prevention of Explosion, Fire, etc., Due to Molten High-temperature Substance, etc.

Article 248 (Structure of High-temperature Substance Handling Facilities)

• (1) The employer shall, as regards furnace and other facilities handling a large quantity of high-temperature substances, ensure that they have a structure necessary to prevent fires.

Article 249 (Molten High-temperature Substance Handling Pit)

• (1) The employer shall, in order to prevent steam explosions, as regards molten high-temperature minerals (hereinafter referred to as “molten high-temperature substance”) handling pit (excluding those processing high-temperature slag with water), take the following measures :
  • (i) To have the structure enabling to prevent underground water from penetrating. However, this shall not apply to when the pits are equipped with facilities enabling discharging stagnant underground water inside the pit.
  • (ii) To install partitions or other facilities enabling to prevent work-use water or rain water from penetrating around the pit.

Article 250 (Structure of Building)

• (1) The employer shall, in order to prevent steam explosions, as regards buildings, which have molten high-temperature substance handling facilities inside, take the following measures:
  • (i) To have a floor surface with structure, which prevent stagnant water.
  • (ii) To have a roof, a wall, a window, etc., with structure enabling to prevent rainwater from penetrating.

Article 251 (Work Handling Molten High-temperature Substance)

• (1) The employer shall, when carrying out the work handling molten high-temperature substance (excluding work processing high-temperature slag with water and work disposing the said slag), in order to prevent steam explosions, not carry out the said work unless otherwise having confirmed that the pit set forth in Article 249, the floor surface of building set forth in the preceding Article, and other molten high-temperature substance handling facilities are free of stagnant water, or are not wet.

Article 252 (Water Processing, etc., of High-temperature Slag)

• (1) The employer shall, as regards places where high-temperature slag are processed with water, or are disposed, in order to prevent steam explosions, take the following measures. However, this shall not apply to the case that water smash processing is carried out:
  • (i) The places where high-temperature slag are processed with water, or are disposed, are of well drained.
  • (ii) The places where high-temperature slag is disposed be indicated that matter.

Article 253

• (1) The employer shall, when carrying out the work processing high-temperature slag with water, or work disposing the said slag, in order to prevent steam explosions, not carry out the said work unless otherwise having confirmed that the places set forth in the preceding Article are free of stagnant water . However, this shall not apply to the case that water smash processing is carried out.

Article 254 (Work Putting Metal Scraps in Furnace)

• (1) The employer shall, when carrying out the work putting metal scraps in a furnace, in order to prevent steam explosions and other explosions, not carry out the said work unless otherwise having confirmed that the said metal scraps are not containing water, gunpowder, dangerous substances (meaning those listed in Appended Table 1 of the Order, the same shall apply hereinafter), airtight containers, etc.

Article 255 (Prevention of Burns, etc.)

• (1) The employer shall, as regards a blast furnace, a cupola, glass melting furnace and other places where work handling a large quantity of high-temperature substances is carried out, in order to prevent burns or other danger due to the scattering, outflow, etc., of the said high-temperature substances, take appropriate measures.
• (2) The employer shall provide the places set forth in the preceding paragraph with appropriate personal protective equipment in order to prevent burns and other dangers.
• (3) A worker shall, when carrying out the work set forth in paragraph (1), use the personal protective equipment set forth in the preceding paragraph.

Section 2 Handling of Dangerous Substances, etc.

Article 256 (Measures in the Case of Manufacture, etc. of Dangerous Substances)

• (1) The employer shall, when manufacturing or handling dangerous substances, in order to prevent explosions or fires, comply with the following provisions:
  • (i) As regards explosive substances (meaning those listed in item (1) of Appended Table 1 of the Order), not to bring them close to fire or others that is liable to become a fire source, or heat, rub them or give a shock to them without reason.
  • (ii) As regards combustible substances (meaning those listed in item (2) of Appended Table 1 of the Order), not to bring them close to fire or others that is liable to become a fire source, or make them to contact with substances that accelerate oxidation or with water, or heat them, or give a shock to them, corresponding to their types, without reason.
  • (iii) As regards oxidizing substances (meaning those listed in item (3) of Appended Table 1 of the Order, the same shall apply hereinafter), not to make them to contact with substances which is liable to accelerate decomposition, or heat, rub them, or give a shock to them without reason.
  • (iv) As regards inflammable substances (meaning those listed in item (4) of Appended Table 1 of the Order, the same shall apply hereinafter), not to bring them close to fire or others that is liable to become a fire source, or pour them, make them to evaporate, or heat them without reason.
  • (v) To always maintain the places installed facilities that dangerous goods are manufactured or handled with good housekeeping, and not to place flammable or oxidizing substances in the said places without reason.
• (2) A worker shall, in the case set forth in the preceding paragraph, comply with the provisions of each item of the same paragraph.

Article 257 (Operations Leader)

• (1) The employer shall, when carrying out the work manufacturing or handling dangerous substances (excluding the work listed in item (ii) or (viii) of Article 6 of the Order), designate a leader for the said work, and have the said leader direct the said work and carry out the following matters:
  • (i) To check as needed the dangerous substances manufacturing or handling facilities and their attached facilities, and when having found any abnormalities, immediately take necessary measures.
  • (ii) To check as needed the temperature, humidity, conditions of shading of light and ventilation, etc., in the place where the dangerous substances manufacturing or handling facilities and their attached facilities are installed, and when having found any abnormalities, immediately take necessary measures.
  • (iii) In addition to what is listed in the preceding each item, to check as needed the situation handling dangerous substances as needed, and when having found any abnormalities, immediately take necessary measures.
  • (iv) To keep records of the measures taken pursuant to the provision of each preceding item.

Article 258 (Work Pouring Inflammable Substances, etc., using a Hose)

• (1) The employer shall, when carrying out the work pouring inflammable substances or combustible gas (meaning those listed in item (5) of Appended Table 1 of the Order, the same shall apply hereinafter) which are in liquid form into a chemical facilities (excluding piping), a tank vehicle, a tank car, a drum, etc., using a hose, not carryout the work unless otherwise having confirmed that the jointing parts of the hose are firmly fastened, or coupled.
• (2) A worker shall, when engaged in the work set forth in the preceding paragraph, not carry out the work unless otherwise prescribed as the same paragraph.

Article 259 (Work Pouring Kerosene, etc., into Facilities with Residual Gasoline)

• (1) The employer shall, when carrying out the work pouring kerosene or light oil into a chemical facilities (limited to the facilities that store dangerous substances, excluding piping; the same shall apply in the next Article), a tank vehicle, a tank car, a drum, etc., in which residual gasoline exists, not carry out the said work unless otherwise having confirmed in advance, that the inside of the chemical facilities, etc., has been made safe by washing, replacing gasoline with inert gas, etc.
• (2) A worker shall, when engaged in the work set forth in the preceding paragraph, not carry out the said work unless otherwise prescribed as the same paragraph.

Article 260 (Work Handling Ethylene Oxide, etc.)

• (1) The employer shall, when carrying out the work pouring ethylene oxide, acetaldehyde or propylene oxide into a chemical facilities, a tank vehicle, a tank car, a drum, etc., not carry out the said work unless otherwise having replaced in advance gas or vapor other than inert gas in the chemical facilities, etc., by inert gas.
• (2) The employer shall, when storing ethylene oxide, acetaldehyde or propylene oxide in a chemical facilities, a tank vehicle, a tank car, a drum, etc., always replace gas or vapor other than inert gas in the chemical facilities, etc., by inert gas.

Article 261 (Prevention of Explosions or Fires by Means of Ventilation, etc.)

• (1) The employer shall, as regards places where it is liable to cause explosions or fires due to existing vapor of inflammable substances, flammable gas or flammable dust, in order to prevent the said explosions or fires, take measures such as ventilation, removal of dust.

Article 262 (Work of Gas Welding, etc., at a Place Where Ventilation, etc., Is Insufficient)

• (1) The employer shall, when carrying out the work welding, cutting or heating of metal using flammable gas and oxygen (hereinafter referred to as “gas, etc.” in this and next Articles) at places where ventilation is insufficient, in order to prevent explosions, fires or burns due to leakage or discharge of gas, etc., at the said places, take the following measures:
  • (i) As regards hoses and torches for gas, etc., to use those that is not likely to leakage of gas etc., due to their damages, wear, etc.
  • (ii) As regards connection of connecting portions between hoses and torches and between hoses of gas, etc., to fasten securely with hose bands, hose clips, etc.
  • (iii) When gas, etc., are supplied to hoses of gas, etc., mount on the hoses a torch that is set so as not to discharge gas, etc., or with a firm stop plug in advance.
  • (iv) To display an indication for preventing operational error of the supply of gas, etc., on the valve or cock of the supply inlet of gas, etc., of the hose in operation,by attaching a card showing the name of the operator who handles the hose connected with the said valve or cock, etc..
  • (v) When carrying out the work cutting, to provide sufficient ventilation to prevent burns due to the discharge of excessive oxygen from the torches.
  • (vi) When leaving the work place due to suspension or completion of the operation, to shut the valve or cock of the supply inlet of gas, etc., and dismantle the hose of gas, etc., from the supply inlet of gas etc., or remove the hose of gas etc., to a place where there is sufficient natural ventilation.
• (2) A worker shall, when engaged in the work set forth in the preceding paragraph, not carry out the said work unless otherwise prescribed as each item of the same paragraph.

Article 263 (Handling of Gas Cylinders, etc.)

• (1) The employer shall, as regards gas cylinders, etc., used for the work of gas welding, etc., (meaning the work listed in item (x) of Article 20 of the Order, the same shall apply hereinafter) comply with the following provisions:
  • (i) Not to install, use, store or leave in the following places:
    • (a) Places where there is insufficient ventilation.
    • (b) Places where fires are used and their vicinities.
    • (c) Places where gun powder, dangerous substances, or other explosive or combustible substances or a large quantity of flammable substances are manufactured or handled and their vicinities.
  • (ii) To keep the temperature of the gas cylinders, etc., at 40°C or lower.
  • (iii) To maintain the gas cylinders, etc., in such a way that they are not likely to fall.
  • (iv) Not to give a shock to the gas cylinders, etc.
  • (v) When transporting the gas cylinders, etc., to provide with caps.
  • (vi) When using the gas cylinder, etc., to remove oil, etc., and dust adhering to the mouthpiece of the cylinder.
  • (vii) To open and close the valve of the gas cylinders, etc., gently.
  • (viii) To place a cylinder of dissolved acetylene upright.
  • (ix) To separate distinctly cylinders before or in use from other cylinders.

Article 264 (Prevention of Ignition, etc., Due to Contact between Different Types of Substances)

• (1) The employer shall, when it is liable to cause ignition or explosion due to contact between different types of substances, not store them close to each other, or take on them by same carrying vehicles. However, this shall not apply to when measures are taken to prevent the said substances from contacting each other.

Article 265 (Places, etc., for Work that Is Liable to Cause a Fire)

• (1) The employer shall ensure that places, equipment, etc., where carried out work raising, rag opening, etc., or work handling a great quantity of cotton, wool, rags, excelsior, straw, wastepaper and other flammable substances, appropriate location or construction to prevent fires.

Article 266 (Prevention of Natural Ignition)

• (1) The employer shall, when piling up substances that are liable to cause danger of natural ignition, take measures to prevent the temperature of the said substances from rising to a dangerous level.

Article 267 (Disposal of Rags, etc., Soaked with Oil, etc.)

• (1) The employer shall, as regards rags, wastepaper, etc., soaked with oil or printing ink, take measures for prevention of fire such as putting them in a non-combustible covered container.

Section 3 Chemical Facilities, etc.

Article 268 (Buildings in Which Chemical Facilities Are Installed)

• (1) The employer shall, as regards a building in which chemical facilities (excluding piping) are installed, use non-combustible materials to construct the walls, pillars, floors, girders, roofs, stairs, etc. (limited to those portions adjacent to such chemical facilities).

Article 269 (Prevention of Corrosion)

• (1) The employer shall, as regards portions that contact dangerous substances or substances with a flash point of 65 oC or higher (hereinafter referred to as “dangerous substances, etc”) among chemical facilities (excluding valves or cocks), take measures such as constructing the said portions with corrosion-resistant materials and providing linings, corresponding to type, temperature or concentration, etc., of the said dangerous substances, etc., in order to prevent explosions or fires due to significant corrosion of the said portions by the said dangerous substances, etc.

Article 270 (Joining Portions of Cover Plates, etc.)

• (1) The employer shall, as regards the joining portions of a cover plate, a flange, a valve, a cock, etc., of chemical facilities, take measures such as using gaskets to make joint surfaces attach tightly in order to prevent explosions or fires due to leakage of dangerous substances, etc., from the said joining portions.

Article 271 (Indicating, etc., the Opening and Closing Direction of Valves, etc.)

• (1) The employer shall, as regards the valves or cocks of chemical facilities or switches, push buttons, etc., for operating the said valves or cocks, take the following measures in order to prevent explosions or fires due to an operational error of the said valves, cocks, etc.:
  • (i) To indicate the direction of opening and closing;
  • (ii) To make distinctions by color, shape, etc.
• (2) The measure in item (ii) of the preceding paragraph shall not be distinction by color only.

Article 272 (Materials of Valves, etc.)

• (1) The employer shall conform the valves or cocks of chemical facilities to the following provisions:
  • (i) To construct such valves or cocks with durable materials corresponding to the frequency of opening and closing of the said valves or cocks, or the type, temperature, concentration, etc., of the dangerous substances, etc., pertaining to producing or handling.
  • (ii) To equip valves or cocks doubly between the strainers, etc. that are opened or removed often during the use of chemical facilities, and the nearest chemical facilities (excluding piping; hereinafter the same shall apply in this item). However, this shall not apply to the case where devices enabling ensure the closing of valves or cocks are equipped between the said strainers, etc., and the said chemical facilities.

Article 273 (Indication of Types of Raw Materials Supplied)

• (1) The employer shall display at a readily visible location the type of raw materials, the facilities in which the raw materials are supplied and other necessary matters in order to prevent explosions or fires due to any error in supplying raw materials by workers who supply raw materials in chemical facilities (excluding piping).

Article 273-2 (Provision of Measuring Instruments)

• (1) The employer shall, as regards special chemical facilities, provide thermometers, flow meters, pressure gauges and other measuring instruments necessary to discover abnormal conditions in the said facilities at an early stage.

Article 273-3 (Installation, etc., of Automatic Warning Device)

• (1) The employer shall, as regards special chemical facilities (excluding those facilities which manufacture or handle dangerous substances, etc., in a quantity less than the standard provided by the Minister of Health, Labour and Welfare), install automatic warning device necessary to discover abnormal conditions inside the said facilities at an early stage.
• (2) The employer shall, when it is difficult to take the measures prescribed by the preceding paragraph, take measures such as placing a watcher and having the person watch the said special chemical facilities during operation.

Article 273-4 (Installation, etc., of Emergency Stop Device)

• (1) The employer shall, as regards special chemical facilities, in order to prevent explosions or fires due to abnormal condition, install device for cutting off feeding of raw materials or discharging products, etc., devices for feeding inert gas, cooling water, etc., or other devices to cope with the said abnormal condition.
• (2) Valves or cocks equipped in the devices set forth in the preceding paragraph shall conform to the following provisions:
  • (i) To have the function to reliably work.
  • (ii) To be maintained in a condition enabling smooth operation at all times.
  • (iii) To enable to safety and accurately operate.

Article 273-5 (Reserved Power Sources, etc.)

• (1) The employer shall conform power sources used for special chemical facilities, their piping or their attached facilities, to the following provisions:
  • (i) To provide reserved power sources for immediate use to prevent explosions or fires due to abnormalities of regular power sources.
  • (ii) To provide locking, color divisions, classification of configurations, etc., on valves, cocks, switches, etc., in order to prevent operational error.
• (2) The measure in item (ii) of the preceding paragraph shall not be distinction by color only.

Article 274 (Work Rules)

• (1) The employer shall, when carrying out the work using chemical facilities or attached facilities, establish the rules for the said facilities as regards the following matters to prevent explosions or fires, and have workers carry out work by the established rules:
  • (i) Operation of valves, cocks, etc. (limited to those used to supply raw materials to or to take products out from chemical facilities [excluding piping]).
  • (ii) Operation of cooling devices, heating devices, stirring devices and compressors.
  • (iii) Monitoring and adjustment of measuring instruments and a control device.
  • (iv) Adjustment of safety devices such as safety valves and emergency stop device and automatic warning device.
  • (v) Inspection for joining portions of covers plates, flanges, valves, cocks, etc., on leakage of dangerous substances, etc.
  • (vi) Sample collection
  • (vii) For specified chemical facilities, work methods during the suspension of operation and at the time of the resumption of operation in the case of operations are temporarily or partially suspended.
  • (viii) Emergency measures in an abnormal situation.
  • (ix) In addition to what is listed in the preceding each item, measures necessary to prevent explosions or fires.

Article 274-2 (Evacuation, etc.)

• (1) The employer shall, in the case that there is imminent danger of an industrial accident due to explosion, fire, etc., owing to a large quantity of leakage of dangerous substances, etc., from chemical facilities, suspend operation immediately and evacuate workers to a safe place.
• (2) The employer shall, in the case set forth in the preceding paragraph, prohibit persons other than those concerned from entering the said workshop, etc., and display a notice to that effect at a readily visible location, until having confirmed that it is unlikely to cause an industrial accident to workers due to dangerous substances, etc.

Article 275 (Modification, Repair, etc.)

• (1) The employer shall, in the case where modifying, repairing or cleaning the chemical facilities or their attached facilities, conform to the requirements prescribed below when disassembling the said facilities or conducting work inside such facilities:
  • (i) To decide in advance the method and procedure of the said work, and make them known to the workers concerned.
  • (ii) To designate a leader of the said work, and have the said leader direct the said work.
  • (iii) Installing double valves or cocks or applying baffles to the valves or cocks in order to prevent dangerous substances, etc. from leaking or high-temperature steam from being discharged inside the work place.
  • (iv) Locking the valves, cocks or baffles described in the preceding item and displaying a sign to the effect that opening such valves, cocks or baffles is prohibited, or placing a watchman.
  • (v) In the case that the baffle, etc., set forth in item (iii) is to be removed and when it is liable to cause leaking or discharging of dangerous substances, etc., or high-temperature steam, to take measures such as confirming in advance, existence of the said dangerous substances, etc., or high-temperature steam between the baffle and the nearest valve or cock.

Article 275-2

• (1) The employer shall, when carrying out the work set forth in the preceding Article, have the vapor of inflammable substances or the concentration of combustible gas at the work place and its surrounding measured as needed.

Article 276 (Periodical Self-inspections)

• (1) The employer shall, as regards a chemical facilities (excluding piping; hereinafter the same shall apply in this Article) and their attached facilities, carry out self-inspections for the following matters periodically once every period within two years. However, this shall not apply to the non-use period of a chemical facilities and their attached facilities, which is not used for a period exceeding two years:
  • (i) The substances inside such facilities that may cause explosions or fires.
  • (ii) Conspicuous damage, deformation and/or corrosion in internal and external surfaces of such facilities.
  • (iii) Condition of lid plates, flanges, valves, cocks, etc.
  • (iv) The functions of safety devices, such as safety valves and emergency stops, and automatic alarms.
  • (v) The functions of cooling devices, heating devices, stirring devices, compressors, measuring instruments and a control device.
  • (vi) The functions of reserve power sources.
  • (vii) In addition to what is listed in the preceding each item, matters especially necessary to prevent explosions or fires
• (2) The employer shall, as regards the chemical facilities and their attached facilities set forth in the proviso of the preceding paragraph, carry out self-inspection for the matters listed in each item of the same paragraph before resuming the use.
• (3) The employer shall, when having found any abnormalities in the said chemical facilities and their attached facilities as a result of the self-inspections set forth in the preceding two paragraphs, not use facilities unless otherwise having repaired them or taken other necessary measures.
• (4) The employer shall, when having carried out the self-inspections set forth in paragraph (1) and (2), record the following matters and preserve the records for three years:
  • (i) The date of the inspection
  • (ii) The method of the inspection
  • (iii) The parts of a machine inspected
  • (iv) The results of the inspection
  • (v) The name of the person who has carried out the inspection
  • (vi) When measures such as repair have been taken based on the result of the inspection, their contents.

Article 277 (Checkup before Commencing Use)

• (1) The employer shall, when using a chemical facilities (excluding piping; hereinafter the same shall apply in this Article) or their attached facilities for the first time, after having remodeled or repaired, or after one month or longer of a nonuse period, not use the said facilities unless otherwise having confirmed that there is no abnormality by check up the matters listed in each item of paragraph (1) of the preceding Article.
• (2) The employer shall, in addition to the case set forth in the preceding paragraph, when changing the use of chemical facilities or their attached facilities (including changes in type of raw materials used; hereinafter the same shall apply in this paragraph), not use the said facilities unless otherwise having confirmed that there is no abnormality by check up the said facilities as regards the matters listed in item (i), (iv) and (v) of paragraph (1) of the preceding Article and as to any abnormalities at the portion reconstructed for such changes in use.

Article 278 (Safety Device)

• (1) The employer shall, as regards vessels in which the pressure of gas is liable to exceed the atmospheric pressure due to an abnormal chemical reaction or other abnormal conditions, not use them unless those are provided with a safety valve or other alternative safety device. However, this shall not apply to those vessels having a volume of 0.1m3 or less.
• (2) The employer shall, as regards a safety valve or alternative safety device for the vessels set forth in the preceding paragraph, in order to prevent explosions or fires due to dangerous substances (In the case that the vessels set forth in the preceding paragraph are chemical facilities (excluding piping) that manufacture or handle substances having a flash point of 65 oC or higher at a temperature of the flash point or higher, the said substances; hereinafter the same shall apply in this paragraph) discharged by the operation of the said safety valve or alternative safety device, use the said safety valve or alternative safety device having an airtight structure, or the structure that enables discharged dangerous substances to be conveyed to a safe place or disposed safely by burning, absorbing, etc.

Section 4 Control of Fires, etc.

Article 279 (Prohibition of Use of Fire at Places Where Dangerous Substances, etc., Exist)

• (1) The employer shall not use machines, etc., or fires that produce sparks or arcs, or that reach a high temperature and are liable to become an ignition source, or use fire at places where it is liable to cause explosion or fire due to existence of combustible dust other than dangerous substances, gunpowder, a large quantity of easily flammable substances or dangerous substances.
• (2) A worker shall not use machines, etc., or fires that are liable to become an ignition source or fire set forth in the preceding paragraph at places set forth in the same paragraph.

Article 280 (Electric Machine and Appliance Used in Places with a Danger of Explosion)

• (1) The employer shall, when using electric apparatuses (meaning those other than wiring and movable electric cable among machines or instruments in which the electricity conducts such as a motor, transformer, cable connector, switch, distribution board or switch board and other equipment, the same shall apply hereinafter) at the place where it is liable that the concentration of the vapor of flammable substance or flammable gas becomes to explosion limit even if the measures set forth in Article 261 are taken, not use unless they are of explosion proof performance corresponding to the types of the said vapors or gases.
• (2) A worker shall not use electric machine and appliance other than explosion-proof types set forth in the preceding paragraph at places set forth in the same paragraph.

Article 281

• (1) The employer shall, as regards places set forth in Article 261, when using an electric machine and appliances at the place where flammable dust (excluding deflagration dust such as the dusts of magnesium and aluminum) is liable to reach the explosible concentration even after the measures set forth in the same Article have been taken, not use electric machine and appliance unless those are of an explosion-proof structure having an explosion-proof capacity for such dust.
• (2) A worker shall not use electric machine and appliance other than the explosion-proof types set forth in the preceding paragraph at places set forth in the same paragraph.

Article 282

• (1) The employer shall, when using electric machine and appliance at places where is liable to cause danger of an explosion due to existing deflagrative dust, not use electric machine and appliance unless those are of an explosion-proof structure having an explosion-proof capacity for such dust.
• (2) A worker shall not use electric machine and appliance other than the explosion-proof types set forth in the preceding paragraph at places set forth in the same paragraph.

Article 283 (Exemptions for Repairing Work, etc.)

• (1) The provisions of the preceding four Articles shall not apply to the case of carrying out the temporary work such as repairing or altering, and when taking measures, which is unlikely to cause dangers of an explosion or fire.

Article 284 (Checkup)

• (1) The employer shall, when using an explosion-proof type electric machine and appliance set forth in Article 280 to 282 (limited to movable or portable ones) pursuant to the provision of the said each Article, check the said explosion-proof type electric machine and appliance and a movable electric cable connected with the said machine, and the condition of the connecting portion of the said machine and appliance and the said conductor before starting the use for the day, and immediately repair it when having found any abnormalities.

Article 285 (Welding, etc., of Piping or a Vessel with Residual Oil, etc.)

• (1) The employer shall, as regards piping or a tank, a drum or other vessels in which inflammable oils or combustible dusts other than dangerous substances, or dangerous substances, are liable to exist, not allow a worker to carry out welding, cutting or other works using fire, or works that is liable to produce sparks unless otherwise measures have been taken in advance, to prevent explosions or fires, such as removing, etc., such inflammable oil or combustible dust other than dangerous substances, or dangerous substances.
• (2) A worker shall not carry out the work set forth in the preceding paragraph until otherwise having taken the measures set forth in the same paragraph.

Article 286 (Welding, etc., at Places Where Ventilation, etc., Is Insufficient)

• (1) The employer shall, when carrying out the work welding, cutting, heating of metal or other using fire, or dry grinding using grinding wheels, chipping using a chisel or other work that is liable to produce sparks, at a place where ventilation is insufficient, not use oxygen for the purpose of ventilation.
• (2) A worker shall not use oxygen for the purpose of ventilation in the case prescribed in the preceding paragraph.

Article 286-2 (Anti-Static Work Clothing, etc.)

• (1) The employer shall, when carrying out the work at the locations set forth in Article 280 and 281 and the places set forth in Article 282, take measures to eliminate static electricity from the bodies and work clothing, etc, of a worker, such as ensuring that the worker engaging in the said work wear anti-static work clothing and anti-static shoes.
• (2) A worker shall, when carrying out the work set forth in the preceding paragraph, not carry out the said work without conforming to the provisions prescribed in the same paragraph.
• (3) The provisions of the two preceding paragraphs shall not apply to the case of carrying out the temporary work such as repairing and altering, and when taking measures, which is unlikely to cause dangers of an explosion or fire.

Article 287 (Removal of Static Electricity)

• (1) The employer shall, in the case where using the following equipment, and when it is liable to cause an explosion or fire due to static electricity, use a grounding, neutralizer, increase humidity, use a neutralization apparatus , which is unlikely to cause an ignition source, and take other measures for eliminating static electricity:
  • (i) The equipment for pouring dangerous substances into a tank vehicle, a tank car, a drum, etc.
  • (ii) The equipment for storing dangerous substances, such as tank vehicles, tank cars, drums, etc.
  • (iii) The equipment for applying paints, adhesives, etc., containing inflammable substances.
  • (iv) Industrial dryers (drying rooms and dryers for heat-drying with a heat source substance other than gunpowder prescribed by paragraph (1) of Article 2 of the Explosive Control Act (Act No.149 of 1950); the same shall apply hereinafter) which heat-dries dangerous substances or materials to be dried that produce dangerous substances (hereinafter referred to as “industrial dryers for dangerous substances”), or their attached facilities.
  • (v) The equipment for spouting, sifting, etc., combustible powder-like substances.
  • (vi) In addition to the facilities listed in the preceding each item, chemical facilities (excluding piping) or their attached facilities.

Article 288 (Prohibition of Entry, etc.)

• (1) The employer shall provide an appropriate indication that use of fire is prohibited at places where there is the danger of fire or explosion, and shall prohibit persons other than those concerned from entering an especially dangerous place.

Article 289 (Fire Extinguishing Equipment)

• (1) The employer shall provide buildings, places where chemical facilities (excluding piping) or industrial dryers are installed, and places where dangerous substances, inflammable oils other than dangerous substances, or other substances that is liable to cause an explosion or fire are handled (hereinafter referred to as “buildings, etc.” in this Article) with fire extinguishing equipment at appropriate locations.
• (2) The fire extinguishing equipment set forth in the preceding paragraph shall have the capacity corresponding to the nature of explosions or fires expected from the scale or floor space of buildings, etc., type of substances handled in the buildings, etc., and other factors.

Article 290 (Fire Prevention Measures)

• (1) The employer shall provide a distance necessary for fire protection between a furnace, heating device, iron stack or other equipment that is liable to cause danger of a fire, and a building or other flammable objects, or shall protect the said flammable objects by insulating materials.

Article 291 (Fire Prevention at Places Where Fire is Used)

• (1) The employer shall provide smoking rooms and places where stoves or other things causing fire are used with equipment necessary to prevent fires.
• (2) A worker shall not perform such as smoke, warmat the fire, and dry without reason.
• (3) A person who uses a fire shall ensure that the fire has been completely extinguished after use.

Article 292 (Ash-Dumping Spot)

• (1) The employer shall install an ash-dumping spot at places where there is no possibility of fire spreading, or shall construct the said spot with incombustible materials.

Section 5 Industrial Dryer

Article 293 (Building with an Industrial Dryer for Dangerous Substances)

• (1) The employer shall make the portion of a building in which industrial dryer for dangerous substances (limited to a drying room; hereinafter the same shall apply in this Article) are installed a single-floor construction. However, this shall not apply to the case where there is no floor just above the floor where the said dryer is installed in the building, or the building is fire-proof or semi-fire-proof.

Article 294 (Structure, etc., of an Industrial Dryer)

• (1) The employer shall conform an industrial dryer to the following provisions. However, this shall not apply to those are unlikely to cause an explosion or fire due to the type of materials to be dried, the extent of heat-drying, the type of heat source, etc.:
  • (i) To construct the outer surface of the industrial dryers with incombustible materials.
  • (ii) To construct the inner surface of the industrial dryers (excluding one for heat-drying organic peroxide substances) and shelves, frames etc., in it with incombustible materials.
  • (iii) For the industrial dryer for dangerous substances, to let the sides and bottom of the said dryer be of a sound structure.
  • (iv) For the industrial dryer for dangerous substances, to construct the top of the said dryer with lightweight materials corresponding to surrounding conditions, or provide an effective explosion door, explosion hole, etc.
  • (v) For the industrial dryer for dangerous substances, to have a structure of the said dryer that enables discharging gas, vapor or dust produced during drying operations that is liable to cause dangers of an explosion or fire to a safe place.
  • (vi) For the industrial dryers using liquid fuel or flammable gas as fuel for heat sources, to have a structure of the said dryer that enables providing ventilation to the combustion chamber or other locations where ignition occurs in order to prevent an explosion or fire at the time of ignition.
  • (vii) To let the inside of the industrial dryers be of a structure that enables it to be cleaned easily.
  • (viii) To provide the openings of the industrial dryers, such as peep windows, manholes and exhaust holes at places where spreading of a fire may be prevented at its ignition, and let be of the structure that enables immediately shut tightly as necessary.
  • (ix) To equip the industrial dryers with a device for measuring the internal temperature of such a dryer as needed and a device for adjusting such temperature to a safe level, or a device for automatically controlling such temperature.
  • (x) Not to use naked fire as a heat source for the industrial dryer for dangerous substances.
  • (xi) When using a naked fire as a heat source for the industrial dryers other than those for industrial dryer for dangerous substances, to provide an effective cover or partition in order to prevent materials to be dried from being ignited by the flames or scattered sparks.

Article 295 (Electric Equipment Attached to an Industrial Dryer)

• (1) The employer shall, as regards a wiring and a switch connecting with an electric heater, a motor, an electric lamp, etc., attached to an industrial dryer, use those purpose-built for the said dryer.
• (2) The employer shall not provide an electric machine and appliance or wiring that are liable to become an ignition source for dangerous substances by producing electric sparks in the industrial dryer for dangerous substances.

Article 296 (Use of Industrial Dryer)

• (1) The employer shall, when carrying out the work using an industrial dryer, in order to prevent an explosion or fire, comply with the following provisions:
  • (i) When using the industrial dryer for dangerous substances, to clean or ventilate in advance the inside of the said dryer.
  • (ii) When using the industrial dryer for dangerous substances, to discharge gas, vapor or dusts produced by drying operations, which are liable to cause danger of an explosion or fire to a safe place.
  • (iii) To hold the materials to be heat-dried using the industrial dryer for dangerous substances in order to prevent such substances from coming off easily.
  • (iv) When using the industrial dryers set forth in item (vi) of Article 294, to make ignition after ventilated the combustion chamber or other places where ignition is to be made.
  • (v) To store flammable substances that have been heat-dried at a high temperature after the temperature of the said substances has been lowered to a level at which no ignition may occur.
  • (vi) Not to place flammable substances at places near the industrial dryers (excluding those outside surfaces do not rise to a very high temperature).

Article 297 (Appointment of an Operations Chief of Industrial Dryers)

• (1) The employer shall, as regards the work set forth in item (viii) of Article 6 of the Order, appoint an operations chief of industrial dryers from the persons who have completed the skill training course for operations chief of industrial dryers.

Article 298 (Duties of an Operations Chief of Industrial Dryers)

• (1) The employer shall have an operations chief of industrial dryers carry out the following matters:
  • (i) When using an industrial dryer for the first time, or when having changed the drying method or the type of materials to be dried, to make in advance the said work method known to the workers, and supervise the said work directly.
  • (ii) To take necessary measures when having found any defective parts in an industrial dryer and it’s attached facilities.
  • (iii) To check as needed the temperature, condition of ventilation and condition of materials to be dried in the industrial dryer, and immediately take necessary measures when having found any abnormalities.
  • (iv) To always maintain the place installed an industrial dryer with good housekeeping and not to place flammable substances in the said place without reason.

Article 299 (Periodical Self-inspections)

• (1) The employer shall, as regards an industrial dryer and its attached facilities, carry out self-inspections for the following matters periodically once every period within a year. However, this shall not apply to the non-use period of chemical facilities and an industrial dryer and its attached facilities, which is not used for a period exceeding one year:
  • (i) Damage, deformation and corrosion both inside and outside of the said facilities and shelves, frames, etc., in it.
  • (ii) For the industrial dryers for dangerous substances, abnormalities in the facilities for discharging gas, vapor or dust produced drying operation that is liable to cause dangers of an explosion or fire.
  • (iii) For the industrial dryers set forth in item (vi) of Article 294, abnormalities in the facilities for ventilation of the combustion chamber or other places where ignition is made.
  • (iv) Abnormalities in openings such as peep windows, manholes, and exhaust holes.
  • (v) Abnormalities in devices for measuring and adjusting the temperature of the inside.
  • (vi) Abnormalities in electric machine and appliance or wiring installed in the said facilities.
• (2) The employer shall, as regards the industrial dryer and its attached facilities set forth in the proviso of the preceding paragraph, carry out self-inspection for the matters listed in each item of the same paragraph before resuming the use.
• (3) The employer shall, when having carried out the self-inspections set forth in the preceding two paragraphs, record the following matters and preserve the records for three years:
  • (i) The date of the inspection
  • (ii) The method of the inspection
  • (iii) The parts of a machine inspected
  • (iv) The results of the inspection
  • (v) The name of the person who has carried out the inspection
  • (vi) When measures such as repair have been taken based on the result of the inspection, their contents.

Article 300 (Repair, etc.)

• (1) The employer shall, when having found any abnormalities in the said industrial dryer and its attached facilities as a result of the self-inspection set forth in paragraph (1) or (2) of the preceding Article, not use the said dryer unless having repaired or taken other necessary measures.

Section 6 Acetylene Welding Equipment and Gas Welding Equipment Using Manifold
Subsection 1 Acetylene Welding Equipmentt

Article 301 (Pressure Limit)

• (1) The employer shall, when carrying out the work welding, cutting or heating of metals using acetylene welding equipment (meaning the one listed in item (i) of Article 1 of the Order, the same shall apply hereinafter), not generate or use acetylene having a pressure exceeding a gauge pressure of 130 kPa.

Article 302 (Generator Room)

• (1) The employer shall, as regards a acetylene generator of acetylene welding equipment (hereinafter referred to as “generator”), install it in a purpose-built generator room (hereinafter referred to as “generator room”)
• (2) The employer shall, as regards a generator room, install it in a floor having no floor just above and at a place considerable distance from equipment using fire.
• (3) The employer shall, when installing a generator room out of doors, install it’s opening at a distance of 1.5 m or more from other buildings.

Article 303

• (1) The employer shall conform a generator room to the following provisions:
  • (i) To be constructed with an incombustible wall, and to have the following structure or a structure with the same strength as the following or more.
    • (a) To be made of ferroconcrete with the thickness of 4 cm or more.
    • (b) To be made of steel or lumber on which metal lath is lined and mortar is painted through 3 cm or more in thickness or of steel on which an iron plate with thickness of 1.5 mm or more are lined.
  • (ii) To use thin iron plate or lightweight incombustible materials for the roof and ceiling.
  • (iii) To project an exhaust pipe having a cross-section area of one-sixteenth of the floor area or more from the roof, and place the opening of the said pipe distance of 1.5 m or more from a window, an entrance and other opening.
  • (iv) To use an iron plate with the thickness of 1.5 mm or more or with structure having the same strength as the iron plate or more using incombustible materials for a door of the entrance.
  • (v) To keep the space between a wall and a generator that does not hinder adjusting of the generator, or the work feeding of carbide, etc.

Article 304 (Storeroom)

• (1) The employer shall, as regards movable acetylene welding equipment, notwithstanding the provisions of paragraph (1) of Article 302, store in an purpose-built storeroom when the said equipment is not used. However, this shall not apply to when storing the equipment after its gas bell is removed and the generator is washed.
• (2) The employer shall, as regards the storeroom set forth in the preceding paragraph, construct it by fire-proof materials such as iron plate-lined lumber and slate-lined lumber.

Article 305 (Construction Codes of Acetylene Welding Equipment)

• (1) The employer shall conform acetylene welding equipment (excluding generators and safety equipment) that generate or use acetylene of a gauge pressure (hereinafter referred to as “pressure” in this Article) of 7 kPa or more to the following provisions.
  • (i) To conform the gas holder to the following provisions.
    • (a) To construct the principal portion of the gas holder with steel plates or steel pipes having a thickness listed in the right column of the following table or more corresponding to the inner diameter listed in the left column of the same table.

      Inner diameter (cm)	Thickness of steel plate or pipe (mm)
      Less than 60	2
      60 or more but less than 120	2.5
      120 or more but less than 200	3.5
      200 or more	5

    • (b) The method of jointing steel plates or steel pipes of the principal portion to be welding, rivet joints or bolt joints.
    • (c) To be equipped with a gas escape valve or a cock to discharge a mixture of acetylene and air.
  • (ii) For the gas holder for acetylene that is compressed by a compressor after fed from the generator, in addition to compliance with the provisions of the preceding item, to be equipped with a safety valve and a pressure gauge as prescribed in the following:
    • (a) Safety valve
      • i.) Those operate before the pressure in the gas holder reaches 140 kPa, and shut while the pressure lowers to a level lower than the normal pressure by 10 kPa.
      • ii.) In the case that the generator generates a maximum quantity of acetylene, those have the capability of keeping the pressure in the gas holder at less than 150 kPa.
    • (b) Pressure gauge
      • i.) The diameter of the dial plate to be 75 mm or more for one mounted on a stationary gas holder, and 50 mm or more for one mounted on a movable gas holder.
      • ii.) The maximum scale of the dial plate to indicate pressures which are 1.5 times the normal pressure or more and500 kPa or less.
      • iii.) For the dial plate, to have an readily visible indication of the normal pressure.
  • (iii) The portions of the gas holder, purifiers, acetylene distributing lines, etc., which contact acetylene not to be constructed with copper or an alloy containing 70% or more copper.
• (2) The employer shall not use copper for the portions of the purifiers, acetylene distributing lines etc., of acetylene welding equipment other than those set forth in the preceding paragraph that is liable to contact acetylene.

Article 306 (Installation of Safety Equipment)

• (1) The employer shall, as regards acetylene welding equipment, provide safety equipment for each torch. However, this shall not apply to when the said safety equipment is provided to the main pipe and each of the branch pipes most close to the torches.
• (2) The employer shall, as regards acetylene welding equipment in which the gas holder and the generator are separated, provide safety equipment between the generator and the gas holder.

Article 307 (Sludge Pit of Carbide)

• (1) The employer shall install a sludge pit at a safe place and conform its construction to following provisions. However, this shall not apply to a mobile acetylene welding equipment used during business trip:
  • (i) Bricks or concrete shall be used.
  • (ii) The capacity of the sludge pit shall be three times that of the carbide charging device or more.

Section 6 Acetylene Welding Equipment and Gas Welding Equipment Using Manifold
Subsection 2 Gas Welding Equipment Using Manifold

Article 308 (Installation of Gas Manifold)

• (1) The employer shall, as regards a gas manifold set forth in item (ii) of Article 1 of the Order (hereinafter referred to as “gas manifold”), install it in a place at a distance of 5 m or more from equipment using fire.
• (2) The employer shall, as regards a gas manifold other than movable one, install it in a purpose-built room (hereinafter referred to as “gas manifold room”).
• (3) The employer shall, as regards the space between the wall of the gas manifold room and a gas manifold, keep sufficient space for handling of the said device, exchanging of a gas cylinder, etc.

Article 309 (Structure of the Gas Manifold Room)

• (1) The employer shall conform a gas manifold room to the following provisions:
  • (i) To not stagnate the gas when leaking gas.
  • (ii) To be constructed with a roof and a ceiling made of lightweight and incombustible materials.
  • (iii) To be constructed with a wall made of incombustible materials.

Article 310 (Piping of Gas Welding Equipment using Manifold)

• (1) The employer shall conform the piping of the gas welding equipment using manifold listed in item (ii) of Article 1 of the Order (hereinafter referred to as “the gas welding equipment using manifold”) to the following provisions:
  • (i) For a joining portion of a flange, a valve, a cock, etc., to take measures of contacting at their joining surface tightly using a gaskets, etc.
  • (ii) To install a safety equipment for the main pipe and branch pipe. In this case, install two or more safety equipment for each torch.

Article 311 (Restriction on the Use of Copper)

• (1) The employer shall not use copper or an alloy containing 70% or more copper for the piping of the gas welding equipment using manifold for dissolved acetylene and its accessories.

Section 6 Acetylene Welding Equipment and Gas Welding Equipment Using Manifold
Subsection 3 Management

Article 312 (Management, etc., of Acetylene Welding Equipment)

• (1) The employer shall, when carrying out the work welding, cutting or heating of metals using acetylene welding equipment, comply with the following provisions:
  • (i) To post the type, model, manufacturer's name, calculated quantity of hourly average gas generation, and the quantity of carbide fed in one lot at a readily visible location in the generator rooms (excluding the gas generators of portable acetylene welding equipment).
  • (ii) To prohibit persons other than those in charge from entering the generator room without reason and display a notice to that effect in an appropriate manner.
  • (iii) To prohibit smoking, use of fire or acts that are liable to produce sparks at places within 5 m from the generators and within 3 m from the generator room, and display a notice to that effect in an appropriate manner.
  • (iv) To take measures to distinguish supply lines for oxygen from those for acetylene.
  • (v) To provide appropriate fire extinguishing equipment at s place where acetylene welding equipment is installed.
  • (vi) Not to install the generators of portable acetylene welding equipment at places where the temperature is high, ventilation is insufficient, there is much vibration, etc.
  • (vii) To have the person engaging in the said work wear eye protector and protective gloves.

Article 313 (Management, etc., of the Gas Welding Equipment using Manifold)

• (1) The employer shall, when carrying out welding, cutting or heating of metal using the gas welding equipment using manifold, comply with the following provisions:
  • (i) To display the name of the gas used and the maximum quantity of gas stored at a readily visible location in the gas manifold room.
  • (ii) When a gas cylinder is exchanged, to have the operations chief of gas welding attend.
  • (iii) To prohibit persons other than those in charge from entering the gas manifold rooms without precautions, and post a notice to that effect at a readily visible location.
  • (iv) To prohibit Smoking, uses of fire or acts that may produce sparks at places within 5 m from the gas manifolds, and post a notice to that effect at a readily visible location.
  • (v) To displaythe guideline of operation and inspection of a valve, a cock, etc., at an easily visible location in the gas manifold room.
  • (vi) To take measures to distinguish supply lines for oxygen from those for gas.
  • (vii) To install appropriate fire extinguishing equipment at the place where a gas manifold are installed.
  • (viii) To have a person engaging in the said work wear eye protector and protective gloves.

Article 314 (Appointment of an Operations Chief of Gas Welding)

• (1) The employer shall, as regards the work set forth in item (ii) of Article 6 of the Order, appoint an operations chief of gas welding from persons who have the license operations chief of gas welding

Article 315 (Duties of an Operation Chief of Gas Welding)

• (1) The employer shall, when carrying out welding, cutting or heating of metal using an acetylene welding equipment, have an operations chief of gas welding carry out the following matters:
  • (i) To decide a work method, and direct the work.
  • (ii) To have the worker engaging in handling acetylene welding equipment carry out the following matters:
    • (a) Not to use a tool which is liable to produce sparks for, or give shocks to, the generator during use.
    • (b) When checking gas leakage from acetylene welding equipment, to use a safe method such as using of soap water.
    • (c) Not to put things on the gas bell of the generator without reason.
    • (d) Not to leave the door of the entrance to the generator room open.
    • (e) When recharging carbide to the generator of portable acetylene welding equipment, to do such operations at a safe place out of doors.
    • (f) When opening a carbide can, not to perform acts that are liable to produce sparks, such as giving shocks.
  • (iii) When starting the said work, to check up acetylene welding equipment, and when a mixture of air and acetylene exists in the generator, remove such a mixture.
  • (iv) To place the safety equipment at a place where its water-level can easily be checked during operations, and check the said safety device once or more a day.
  • (v) When keeping warm or heating the acetylene welding equipment to prevent water in the equipment from freezing, to apply a safe method, such as using warm water or steam.
  • (vi) When suspending the use of the generator, to keep its water level in such a condition that water and residual carbide may not contact each other.
  • (vii) When repairing, processing, transporting or storing the generator, or suspending its use continuously, to remove acetylene and carbide from it completely.
  • (viii) To dispose carbide sludge in a safe manner such as keeping it in a sludge pit until the danger due to gas is removed.
  • (ix) To monitor the use of eye protector and protective gloves by workers engaged in the said work.
  • (x) To carry the license of an operations chief of gas welding.

Article 316

• (1) The employer shall, when carrying out welding, cutting or heating of metal using the gas welding equipment using manifold, have the operations chief of gas welding carry out the following matters:
  • (i) To decide a work method and supervise the work directly.
  • (ii) To have the worker engaging in the handling of the gas manifolds carry out the following matters:
    • (a) To remove oil, etc., and dust, etc., adhering to the mouthpiece of the gas cylinder and the mounting opening of the piping.
    • (b) When having exchanged gas cylinders, to check the mouthpiece of the gas cylinder and the mounting opening of the piping for leakage of gas, and remove the mixture of the gas and air in the piping.
    • (c) When checking leakage of gas, to apply safe method such as using soap water.
    • (d) To Open and close the valve or cock gently.
  • (iii) To be present when the gas cylinders are exchanged.
  • (iv) When starting the said work, to check the hose, torch, hose band, etc. , and when having found that there is a danger of leakage of gas or oxygen due to damage, wear, etc., to repair or exchange the parts damaged, worn, etc.
  • (v) To place the safety equipment at a place where its functions can easily be observed, and check the said safety device once or more a day.
  • (vi) To monitor the use of eye protector and protective gloves by workers engaged in the said work.
  • (vii) To carry the license of an operations chief of gas welding.

Article 317 (Periodical Self-inspections)

• (1) The employer shall, as regards an acetylene welding equipment or a gas welding equipment using manifold (excluding the portions of the piping of those devices installed underground; hereinafter the same shall apply in this Article), carry out self-inspections for the existence of damage, deformation, corrosion, etc., and the functions of the said equipment periodically once every period within a year. However, this shall not apply to the non-use period of an acetylene welding equipment or a gas welding equipment using manifold, which is not used for a period exceeding one year.
• (2) The employer shall, as regards the acetylene welding equipment or a gas welding equipment using manifold set forth in the proviso of the preceding paragraph, carry out self-inspection for the matters prescribed by the same paragraph before resuming the operation.
• (3) The employer shall, when any abnormality is found in the said acetylene welding equipment as a result of the self-inspections set forth in the preceding two paragraphs, not use the said equipment unless repair or other necessary measures have been taken.
• (4) The employer shall, when having carried out the self-inspections set forth in paragraph (1) and (2), record the following matters and preserve the records for three years:
  • (i) The date of the inspection
  • (ii) The method of the inspection
  • (iii) The parts of a machine inspected
  • (iv) The results of the inspection
  • (v) The name of the person who has carried out the inspection
  • (vi) When measures such as repair have been taken based on the result of the inspection, their contents.

Section 7 Blasting Work

Article 318 (Standards of Blasting Work)

• (1) The employer shall have the worker engaging the work set forth in item (i) of Article 20 of the Order (hereinafter referred to as “blasting work”) carry out the following matters:
  • (i) Not to defreeze frozen dynamite by a dangerous method, such as bringing it in proximity to fire or in direct contact with a steam pipe or other high-temperature object.
  • (ii) When charging gunpowder or explosives, not to use naked fire or smoke nearby.
  • (iii) To use a safe charging tool, which are unlikely to cause an explosion due to friction, shock, static electricity, etc.
  • (iv) To use a safe stemming, which are unlikely to cause an ignition or an inflammation, such as clay or sand.
  • (v) When the charged gunpowder does not explode after ignition, or when it is difficult to confirm that the charged gunpowder has exploded, to comply with the following provisions:
    • (a) When using an electric detonator, to remove the blasting leading wire from the igniter and make the end of the said leading wire short-circuit, and take measures to prevent re-ignition; and not to approach the place where the gunpowder is charged within five minutes after the above measures are taken.
    • (b) When using device other than an electric detonator, not to approach the place where the gunpowder is charged within 15 minutes after ignition.
• (2) The worker engaging in the work set forth in the preceding paragraph shall carry out the matters listed in each item of the same paragraph.

Article 319 (Leader for Fuse Blasting Work)

• (1) The employer shall, when carrying out fuse blasting work, appoint a leader from those eligible to the said work, and have the said leader carry out the following matters:
  • (i) To instruct workers other than those engaging in igniting work to evacuate the work site before ignition.
  • (ii) To instruct workers engaging in the igniting work on the place for evacuation and the route to the place.
  • (iii) When a worker takes charge of five or more ignitions at a time, have each worker use device notifying the time of evacuation such as a blasting watch and waste fuses.
  • (iv) To instruct workers on the procedures and specification of the igniting work.
  • (v) To give a signal of ignition.
  • (vi) To give a signal of evacuation to workers engaging in the igniting work.
  • (vii) To check misfires or for residual gunpowder.
• (2) The leader for fuse blasting work shall carry out the matters listed in each item of the preceding paragraph.
• (3) The worker engaging in the fuse blasting work shall follow the instructions and signals given by the leader pursuant to the provision of the preceding paragraph.

Article 320 (Leader for Electric Blasting Work)

• (1) The employer shall, when carrying out electric blasting work, appoint a leader from those eligible to the said work and have the said leader carry out the matters set forth in items (v) and (vii) of paragraph (1) of the preceding Article and the following matters:
  • (i) To instruct the workers engaging in the said work on the place for evacuation and the route to the place.
  • (ii) To confirm that workers have been evacuated the dangerous area before ignition.
  • (iii) To appoint a person in charge of ignition.
  • (iv) To give instructions on the place of ignition.
• (2) The leader of the electric blasting work shall carry out the matters listed in each item of the preceding paragraph.
• (3)The worker engaging in the electric blasting work shall follow the instructions and signals given by the leader pursuant to the provision of the preceding paragraph.

Article 321 (Evacuation)

• (1) The employer shall, in the case of a blasting work, and when it is impossible for workers to evacuate to a safe distance from the work site, provide an evacuation shelter with a solidly protected front and top.

Section 7-2 Concrete Breaking Work

Article 321-2 (Standards for Concrete Breaking Work)

• (1) The employer shall, when carrying out the breaking work using a concrete breaker, comply with the following provisions:
  • (i) When charging a concrete breaker, to prohibit the use of naked fire or smoking nearby.
  • (ii) To use a safe charging tool, which is unlikely to cause ignition of the concrete breaker due to friction, shock, static electricity, etc.
  • (iii) To use a safe stemming, which is unlikely to cause ignition or inflammation, such as cement mortar or sand.
  • (iv) To take measures to prevent broke substances, etc., from scattering.
  • (v) When the charged concrete breaker does not ignite after ignition, or when it is difficult to confirm that the charged concrete breaker has ignited, to remove the lead wire of the said blaster from the igniter and make the end of the said lead wire a short-circuit, and to take measures to prevent re-ignition; and not to allow the worker engaging in the concrete breaking work to approach the place where the said concrete breaker is charged within five minutes after the above measures had been taken.

Article 321-3 (Appointment of an Operations Chief of Concrete Breaking)

• (1) The employer shall, as regards the work set forth in item (viii)-2 of Article 6 of the Order, appoint an operations chief of concrete breaking from the persons who have completed the skill training course for operations chief of concrete breaking.

Article 321-4 (Duties of an Operations Chief of Concrete Breaking)

• (1) The employer shall have an operations chief of concrete breaking carry out the following matters:
  • (i) To decide a work method and supervise the work directly.
  • (ii) To instruct workers engaging in the said work on the place for evacuation and the route to the place.
  • (iii) To confirm that workers have been evacuated the dangerous area before ignition.
  • (iv) To appoint a worker in charge of ignition.
  • (v) To give a signal of ignition.
  • (vi) To check misfires or residual gunpowder.

Section 8 Miscellaneous Provisions

Article 322 (Underground Workshop, etc.)

• (1) The employer shall, when carrying out the work at underground workshop where is liable to generated flammable gas, (excluding the case of carrying out construction works of tunnels etc., prescribed by Article 382) or when carrying out an open-cut excavation work(meaning the excavation work of natural ground or transportation, etc., of earth and rocks associated with the excavation [limited to those work which are carried out at places where excavating work of natural ground are carried out and in the vicinity of the said places]; the same shall apply hereinafter) at places where is liable to discharged gas from gas supply lines, take the following measures in order to prevent an explosion or fire:
  • (i) To appoint a person in charge of measuring the concentration of these gas, and have the said person measure the concentration of these gas every day before commencing the work and whenever having found any abnormality related to these gas at places where is liable to generated or stagnant these gas.
  • (ii) When having found the concentration of these gas to reach 30 % or more of the value of the explosion lower limit, have workers evacuate to a safe place immediately, suspend use of fire or any other things that is liable to become an ignition source, and provide drafting, ventilation, etc.

Articles 323 and 324 (Deleted)

Article 325 (Place Where Strong Light Is Emitted)

• (1) The employer shall enclose places where is liable to cause dangers due to strong lightsuch as welding ark is emitted. However, this shall not apply to when it is inevitable due to the nature of the operation.
• (2) The employer shall, as regards places set forth in the preceding paragraph, provide appropriate personal protective equipment.

Article 326 (Pressurized Feeding Facilities of Corrosive Liquid)

• (1) The employer shall, when carrying out the work of pressure feeding with power and through hoses those liquids which is liable to cause danger of a corrosive effect on the skin, such as sulfuric acid, nitric acid, hydrochloric acid, acetic acid, chlorosulfonic acid, caustic soda solution and cresol (hereinafter referred to as “corrosive liquids”), take the following measures for the facilities used in the said work:
  • (i) To provide a pressure gauge at a readily visible location for the person who operates the said facilities used for pressure feeding(hereinafter referred to as the “operator” in this Article), and a power cutting-off device at a place where the operator can easily operate it, respectively.
  • (ii) To use the hoses and their connecting tools that have anti-corrosiveness, heat-proofing and cold-proofing to the corrosive liquids fed.
  • (iii) For hoses, to set the pressure for their safe use by conducting hydraulic tests, etc., and indicate the set pressure on hoses, and not to feed using a pressure exceeding the pressure.
  • (iv) When it is liable to an abnormal pressure acting on the inside of hoses, to provide the facilities used for pressure feeding with preventive device for excessive pressurizing such as unloaders and return valves.
  • (v) To connect securely the connecting parts of hoses and pipes other than hoses, and between hoses using connecting tools.
  • (vi) When carrying out pressure feeding at a gauge pressure exceeding 200 kPa, as regards the connecting tool set forth in the preceding item, to use those which structure is unlikely to cause disconnection due to the said pressure such as of the screwed-connection type, three-hook connection type, etc., those having three or more bottoms at the part mounted hoses, etc.
  • (vii) To appoint an operator and have the said operator watch the operation of the facilities used for pressure feeding and the pressure gauge.
  • (viii) To check hoses and their connecting tools before commencing the use of the day, and to exchange them when it is liable to cause scattering or leakage of corrosive liquids due to defect such as damage and corrosion.

Article 327 (Personal Protective Equipment)

• (1) The employer shall have the worker engaging in pressure feeding work of corrosive liquids wear personal protective equipment necessary to prevent the body from the danger of corrosion due to scattered, leaked or overflowing corrosive liquid.
• (2) The worker engaging in the work set forth in the preceding paragraph shall, when having been instructed to wear the personal protective equipment set forth in the same paragraph, wear it.

Article 328 (Restriction on the Use of Gas Other Than Air)

• (1) The employer shall, when carrying out the pressure feeding work of corrosive liquid using the pressure of compressed gas as power source, not use gas other than air for the said compressed gas. However, in the case of having completed the said work, and when removing the said gas immediately, or when taking measures of indicating the existence of the said gas, etc., which are unlikely to cause danger of suffocation due to workers entering the facilities used for the said pressure feeding, nitrogen or carbon dioxide gas may be used.

Article 328-2 (Work Standards for Filling Tires with Air)

• (1) The employer shall, in the case of assembling a tire for an automobile (excluding two-wheeled vehicle) (hereinafter referred to as “tires” in this Article) and filling a tire with air using an air compressor, in order to prevent danger due to a burst tire, etc., have the worker engaging in said work adjust air pressure appropriately corresponding to the type of tire and use appliances such as safety enclosures etc., in order to prevent pieces of burst tires, etc., from flying.
• (2) The worker engaging in the work set forth the preceding paragraph shall adjust air pressure appropriately corresponding to the type of tire and use the appliances set forth in the same paragraph.

Article 328-3 (Ship Refitting, etc.)

• (1) The employer shall, in the case of carrying out ship refitting, repairs and cleaning, etc., and when carrying out the work using machine, etc., that generates sparks or arcs or reaches high temperatures, becoming a potential source of ignition, or work using fire in areas inside the said ship such as the hold or adjoining areas, measure the concentrations of vapor of inflammable substances and flammable gas in the work place and surrounding areas before commencing the said work and as needed during said work.

Article 328-4 (Refitting, etc., of Equipment for the Manufacture of Liquid Oxygen)

• (1) The employer shall, in the case of carrying out refitting, repairing and cleaning, etc., of the facilities for the manufacture of liquid oxygen, and when carrying out the said work inside the said facilities, comply with the following provisions:
  • (i) To decide the method and procedure of the said work, and make them known to the workers concerned in advance.
  • (ii) To designate a leader for the said work and have the said leader directs the said work.
  • (iii) To close valves or cocks doubly or apply baffle in addition to closing valves or cocks in order to prevent the work place from leakage of oxygen.
  • (iv) To lock the valves, cocks and baffle set forth in the preceding item, indicate an instruction that they shall not be opened or place a watcher.

Article 328-5 (Manufacturing, etc., of Hydroxylamine etc.)

• (1) The employer shall, when manufacturing and handling hydroxylamine or its salt (hereinafter referred to as “hydroxylamine etc.” in this Article), in order to prevent explosion, comply with the following provisions:
  • (i) To take measures to prevent the abnormal reaction between hydroxylamine, etc., and ferrous ion, etc., such as prevention of interfusion of ferrous ion etc., to hydroxylamine etc.
  • (ii) When carrying out the heating work of hydroxylamine, etc., to adjust temperature.

• Part II Safety Standards
• << INDEX
• Chapter I
• Chapter I-2
• Chapter II
• Chapter III
• Chapter IV
• Chapter V
• Chapter VI
• Chapter VII
• Chapter VIII
• Chapter VIII-2
• Chapter VIII-3
• Chapter VIII-4
• Chapter VIII-5
• Chapter VIII-6
• Chapter IX
• Chapter X
• Chapter XI
• Chapter XII

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