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
掲載日：2008.03.28
Part II Safety Standards
Chapter X Passage, Scaffolding, etc.
Section 2 Scaffolding
Sub-section 1 Materials, etc.
Article 559 (Materials, etc.)
- (1) The employer shall, as regards the materials of scaffolding, not use those having marked damage, deformation or corrosion.
- (2) The employer shall, as regards the lumbers used for scaffolding, not use unless they are free from cracks, worm-eaten spots, knars, slant fibers or other defects affecting the strength of the lumber greatly, and of which the bark is removed.
Article 560 (Steel Pipe, etc., for Steel Pipe Scaffolding)
- (1) The employer shall, as regards the steel pipes used for steel pipe scaffolding, not use unless they conform to the standards of steel pipes of the Japanese Industrial Standard A 895l, (Steel Pipe Scaffoldings) (hereinafter referred to as the “steel pipe standards”), or conform to the following provisions:
- (i) The material is to be of tensile strength of 370 N/mm2 or more and elongation of the value listed in the right column of the following table corresponding to the value of tensile strength listed in the left column of the same table.
Tensile strength (N/mm2) Elongation (%) 370 or more but less than 390 25 or more 390 or more but less than 500 20 or more 500 or more 10 or more - (ii) The thickness to be one-thirty first or more of the outer diameter.
- (i) The material is to be of tensile strength of 370 N/mm2 or more and elongation of the value listed in the right column of the following table corresponding to the value of tensile strength listed in the left column of the same table.
- (2) The employer shall, as regards the fittings used for steel pipe scaffoldings, not use unless they conform to the standards of fittings of the Japanese Industrial Standard A 8951 (Steel Pipe Scaffoldings) or conform to the following provisions:
- (i) Materials (excluding those of parts used in portions that may not be subject to shock) to be rolled steels, forged steels or cast steels.
- (ii) As regards couplings, in the case that they are used to couple steel pipes at the center of fulcrums (meaning fulcrums having the maximum distance between them during work) and the maximum load during work is applied to them as concentrated load, the strain of the said couplings to be 1.5 times or less of that of steel pipes of the same type without such coupling under the same condition.
- (iii) As regards clamps, in the case that they are used to fasten steel pipes at a right angle and a load two times of the maximum operational load is applied onto the fastened portion, the slip to be 10 mm or less.
Article 561 (Structure)
- (1) The employer shall, as regards scaffoldings, not use unless they are of sound structure.
Article 562 (Maximum Loading Capacity)
- (1) The employer shall determine the maximum loading capacity of a working floor of scaffolding corresponding its structure and materials, and shall not take on exceeding that.
- (2) The maximum loading capacity of the working floor set forth in the preceding paragraph shall, as regards hanging scaffoldings(excluding hanging scaffoldings of gondolas; hereinafter the same shall apply in this Section), be so determined as to ensure the safety coefficient of 10 or more for hanging wire ropes and hanging steel wires, the safety coefficient of 5 or more for hanging chains and hanging hooks, and the safety coefficient of hanging steel bands and of fulcrums at the bottom and top of the hanging scaffoldings of 2.5 for steels and 5 or more for logs.
- (3) The employer shall make the maximum loading capacity set forth in paragraph (1) known to workers.
Article 563 (Working Floor)
- (1) The employer shall provide a work place on scaffolding (excluding single-row scaffolding) having a height of 2 m or more with a working floor as prescribed in the followings:
- (i) The floor materials to be with bending stress calculated corresponding to the distance between fulcrums and the load applied during work not exceeding the value of allowable bending stress listed in the right column of the following table corresponding to the type of lumber listed in the left column of the same table.
Type of lumber Allowable bending stress (N/cm2) Japanese red pine, Japanese black pine, Japanese larch, hiba, hinoki, Japanese hemlock, Oregon pine, or Port Oxford cedar 1,320 Japanese cedar, fir, silver fir, abies, red cedar, or Western hemlock 1,030 Oak 1,910 Japanese chestnut, Japanese oak, Japanese beech or Keyaki 1,470 Plywood manufactured by gluing apitong or kapur with phenol resin 1,620 - (ii) The width to be of 40 cm or more and the clearance between floor boards to be of 3 cm or less, excluding hanging scaffoldings.
- (iii) To provide places where is liable to cause dangers to workers due to fall with handrails, etc., prescribed as follows. However this shall not apply to the case that it is extremely difficult to provide the said handrails, etc., due to the nature of the work, or in the case the said handrails, etc., are temporarily removed according to the needs of the work and a protective net is set, safety belts are provided to workers or other measures are taken to prevent the dangers to workers due to a fall this shall not apply.
- (a) To be of sound structure;
- (b) To be made of materials without marked damage, corrosion, etc.;
- (c) To have the height of 75 cm or more.
- (iv) To use brackets, ledgers, girders, trestle or other supporting materials for the working floor having strength sufficient to bear the load applied.
- (v) To fix the floor boards to two supports or more to prevent displacement or coming off, excluding hanging scaffoldings.
- (i) The floor materials to be with bending stress calculated corresponding to the distance between fulcrums and the load applied during work not exceeding the value of allowable bending stress listed in the right column of the following table corresponding to the type of lumber listed in the left column of the same table.
- (2) The provisions set forth in item (v) of the preceding paragraph shall not apply when they fall under any of the following each item:
- (i) When boards having a width of 20 cm or more, a thickness of 3.5 cm or more and a length of 3.6 m or more are used for the floor materials and the said boards are to be moved according to the work, and when the following measures are taken:
- (a) Scaffolding boards to be supported by three or more supports.
- (b) The length of projection of scaffolding boards from the fulcrums to be of 10 cm or more, and is one-eighteenth of the length of the said scaffolding boards or less, excluding when there is no possibility that workers will step on the said projections.
- (c) When scaffolding boards to be lapped longitudinally, they are lapped on their fulcrum, and the length of such lapped portion to be of 20 cm or more.
- (ii) When boards having a width of 30 cm or more, a thickness of 6 cm or more and a length of 4 m or more are used, and the measures provided in (b) and (c) of the preceding item are taken.
- (i) When boards having a width of 20 cm or more, a thickness of 3.5 cm or more and a length of 3.6 m or more are used for the floor materials and the said boards are to be moved according to the work, and when the following measures are taken:
- (3) A worker shall, in the case of the proviso of item (iii) of paragraph (1), when having been instructed to use safety belts, etc., use them.
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