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 4 Steel Pipe Scaffolding
Article 570 (Steel Pipe Scaffolding)
- (1) The employer shall, as regards steel pipe scaffoldings, not use unless they conform to the following provisions:
- (i) For the leg of scaffolding (excluding movable scaffoldings with casters), to take measures such as providing bridge batten of foot posts with base fittings, and plankings, square timbers, etc., in order to prevent the scaffolding from sliding or settling;
- (ii) For movable scaffolding with casters, to take measures such as securely fixing the casters with a brake, or other brakes, pawl, etc. or fastening a part of the scaffolding to a sound building, in order to prevent scaffoldings from moving unexpectedly, ;
- (iii) To joint or fasten the jointing portions or crossing portions of steel pipes securely with suitable fittings.
- (iv) To reinforce the scaffolding with bracings.
- (v) For single row scaffolding, double row scaffolding or cantilever scaffolding, to provide ties to wall or stays prescribed as follows:
- (a) The interval to be the value listed in the right column of the following table or less corresponding to the type of steel pipe scaffolding listed in the left column of the same table.
Type of steel pipe scaffolding Interval (m) Vertical direction Horizontal direction Tube and coupler scaffolding 5 5.5 Prefabricated scaffolding (excluding those having height of less than 5 m) 9 8 - (b) To make the scaffolding strong with materials such as steel pipes and logs.
- (c) When the scaffoldings are composed of tension members and compression members, the interval between these members to be within 1 m.
- (a) The interval to be the value listed in the right column of the following table or less corresponding to the type of steel pipe scaffolding listed in the left column of the same table.
- (vi) When a scaffolding is installed near an overhead power line, to take measure to prevent contact with the said overhead power line such as moving the said overhead power line or installing protecting equipment for insulating.
- (2) The provision of paragraph (3) of the preceding Article shall apply mutatis mutandis to the application of the provision of item (v) of the preceding paragraph. In this case, the term “item(vi) of paragraph (1)” in paragraph (3) of the preceding Article shall be deemed to be replace with “item (v) of paragraph (1) of Article 570”.
Article 571 (Steel Pipe Scaffolding Conforming to the Steel Pipe Standards)
- (1) The employer shall, as regard the steel pipe scaffoldings composed of steel pipes conforming to the steel pipe standards, in addition to the provisions of paragraph (1) of the preceding Article, not use unless they conform to following item (i) to (iv) for single pipe scaffoldings and item (v) to (vii) for prefabricated scaffoldings:
- (i) The intervals of the standards to be of 1.85 m or less in the direction of the crossbeam and 1.5 m or less in the direction of the beam;
- (ii) To provide the first ledger above the ground at the height of 2 m or less ;
- (iii) The standards exceeding 31 m measured from the highest point of the standards to consist of the combination of two steel pipes;
- (iv) To limit the loading capacity between the standards to 400 kg.
- (v) To provide the horizontal members at the top level and at every fifth level or less.
- (vi) To take measures to prevent the beam frames and bracket frames from moving laterally with horizontal bracings.
- (vii) When the scaffolding having a height exceeding 20 m, and when the work involves carrying heavy material are carried out, the main frame to be with the height of 2 m or less, and the intervals of 1.85 m or less.
- (2) The provisions of item (i) or item (iv) of the preceding paragraph shall not apply to the case that it is difficult to comply with the said provisions due to necessity of works and when the employer takes the measures prescribed by the next Article as to the value of the maximum bending moment obtained by the calculation supposing that members between each fulcrum are those of simple beams.
- (3) The provision of item (ii) of paragraph (1) shall not apply to the case that it is difficult to comply with the said provisions due to necessity of works and when the said portions are reinforced with two steel pipes combined, etc.
Article 572 (Steel Pipe Scaffolding Constructed by Steel Pipes Other Than Those Conforming to the Steel Pipe Standards)
- (1) The employer shall, as regards steel pipe scaffoldings composed of steel pipes other than those conforming to the steel pipe standard, in addition to conform to the provisions of paragraph (1) of Article 570, not use them unless the value of the maximum bending moment between fulcrums calculated by assuming as simple beam structure does not exceed the value obtained by multiplying the section modulus of steel pipe with 1/1.5 of yield point of material of steel pipe (for the yield point is not known, 1/2 of the tensile strength) and coefficients listed in the right column of the following table (in the case that the yield point is unkown, joints are used, 3/4 of the value of the factor) corresponding to the ratio of thickness to outer diameters listed in the left column of the same table.
Ratio of thickness to outer diameter of steel pipe Coefficient Thickness, 1/14 or more of outer diameter. 1 Thickness, 1/20 or more and less than 1/14 of outer diameter. 0.9 Thickness, 1/31 or more and less than 1/20 of outer diameter. 0.8
Article 573 (Distinction of Strength of Steel Pipes)
- (1) The employer shall, when using steel pipes of the same or similar outer diameter and thickness which differ in strength in the same workplace, in order to prevent dangers to workers due to confused use of such steel pipes, take measures to distinguish the strength by colouring on pipe surface, affixing symbols, etc.
- (2) The measure in the preceding paragraph shall not be the distinction by color only.
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