The Safety Standards of Scaffolding

1.      PURPOSE

     This procedure provides guidelines for the safe erection, inspection, use, and dismantling of scaffolding at Air Products Facilities worldwide.
   
2.      SCOPE

     This procedure applies to all personnel who erect, inspect, use, or dismantle scaffolding. Air Products plant personnel must ensure that all contractors engaged in any scaffolding activities shall comply with the provisions in this procedure.
   
3.      SUMMARY

3.1      Scaffold design and specification shall as a minimum follows the nationally recognized and approved standards of the country in which the scaffold is erected. Where the requirements of this standard are different to the nationally recognized and approved standards, the most stringent standard will apply.
   
3.2      Scaffolds shall be inspected by competent qualified and certified personnel prior to use, after inclement weather and any occurrence where the structure has been modified. Any individual that erects or disassembles a scaffold must be certified, and all users of scaffolding must receive the appropriate training. Contract personnel must present proof of the appropriate training and qualifications prior to working on any Air Products site.
   
3.3      Scaffolds shall only be erected and disassembled by competent approved and qualified personnel. Proper provisions must be made for the safe lifting of scaffold      fittings, poles and boards. Lifting equipment must be designed to prevent the possibility of scaffold falling to grade in the event that the load snags or knots slip. Throwing and droppin
documented翻译
g equipment is strictly prohibited.


3.4      Erected scaffolds exceeding 38m (125' feet) in height (or the national limits in the country of use) shall be designed by a registered professional engineer, or the local authority where applicable, and shall be constructed and loaded in accordance with such design.
   

3.5      The person(s) in charge of the activity, e.g., plant maintenance, construction, etc., shall ensure that any individual that has the authority and responsibility for the erection, inspection, and disassembly of scaffolding is competent to do so. The individual will be deemed competent after receiving suitable training by an approved scaffold training company or in-house expert and shall be documented.
   


3.6      Scaffolds shall have guardrails, mid-rails, and toe boards installed on all open sides and ends of platforms.
   

3.6.1      Guardrails shall be installed no less than 970 mm (38" inches) or not more than 1,140 mm (45" inches) high with a mid-rail, or as required by the National Standard. There must not be a gap between guardrails, or between toe boards and guardrails, greater than 470 mm (18" inches).
   

3.6.2      Toe boards shall be a minimum of 102 mm (4" inches) in height and must be secured to prevent movement. Toe boards are to be of wood construction, aluminum, or steel preformed to match the scaffold.
   


3.6.3      In windy conditions and certain situations, netting must be placed between the toe board and mid-rails (and top rails in some cases) to prevent materials, i.e. paper, rags, small tools; various materials from being blown off the scaffold decking and falling onto the ground exposing people below to fall hazards.


3.7      Scaffolds must be erected on sound surfaces and base plates must be used at all times. Footing or anchorage for scaffolds shall be rigid, and capable of carrying the maximum intended load without settling or displacement. Unstable objects such as barrels, boxes, loose brick or concrete blocks shall not be used to support scaffolds.
   
3.8      All poles, legs, or uprights of scaffolds shall be plumb and rigidly braced to prevent swaying and displacement. Sufficient ties or raking shores shall be provided to ensure that the scaffold cannot fall away from the object being scaffolded.
   

3.9      Scaffold surfaces shall be kept clean and free from sharp edges, burrs, or other safety hazards.
   

3.10      Scaffolds shall not be loaded in excess of the working load for which they are intended. Scaffolds and their components shall be capable of supporting at least four (4) times the maximum intended load. Scaffolds should have their safe working loads posted or visible to those working who will be performing work on the scaffold.
   
3.11      Scaffold work platforms shall be fully planked with wood, aluminum, or steel scaffold planks or 51 mm X 254 mm (2" x 10" inches) lumber that meets Planking Requirements and is rated to support the intended load.
   
3.12      Scaffolds shall be maintained in a safe condition, and shall only be altered by competent approved and qualified personnel. Scaffolds undergoing modification shall be withdrawn from use until the modification work has been completed, and the scaffold inspected and approved for use by a competent approved and qualified person.

3.13      Scaffolds (including mobile access towers) shall not be moved while they are in use or occupied.
   
3.14      Scaffolds damaged or part weakened from any cause shall immediately be replaced and shall not be used until repairs have been completed and the scaffold re-inspected.
   
3.15      The preferred method of access and egress to a work platform is from a ladder which shall be fitted with an access gate panel. Chain gates can only be used where access gate panels are not safely accessible. Access ladders should not exceed 9m (30' fe
et) in length, and shall extend a min. of 1.1m (3.5' feet) past the working platform.
   
3.16      Access ladder(s) shall be provided with each scaffold built. Access ladders must be of an approved construction, fixed on a suitable foundation, and unpainted. The ladders should be fixed at the top, bottom, and sufficient intermediate points to prevent undue sagging or movement. The recommended gradient is to be 1:4 (i.e.,      about 1 unit out for every 4 units in height). A chain gate shall be used on ladder frames when access gate panels are not safely accessible.
   
3.17      Access or working platforms shall be no more than 9m (30' feet) apart vertically. When a scaffold height exceeds 9 m (30' feet) all additional platforms shall be on the inside of the scaffolding. If the working platforms are spaced more than 6.1m (20' feet)) apart, the ladders shall then be equipped either self- retracting lifelines or an OSHA or equivalent National approved cage. The lifeline shall be installed to an acceptable anchorage point capable to withstand 2300Kgs or (5000 Lbs) per individual attached for fall protection. Any l
adder over 7.3m (24' feet) or 9.1m (30' feet) must have an intermediate platform as a means for resting on the way up.
   
3.18      Use of pulleys, hoist arms, or other devices to hoist material is prohibited, unless the scaffold is guyed or braced to a permanent structure to prevent tipping or has been designed to accommodate these lifting devices.
 
3.19      Use of ladders or makeshift devices on top of scaffold to increase its height or to provide access from above is prohibited.
   
4.      PROCEDURE

4.1      Safety Considerations
   
4.1.1      Depending on the nature and the area of work, appropriate personal protective eq
uipment must be worn by personnel. A competent person must determine the feasibility and safety, or where National Standards may dictate, of providing fall protection during the erection and dismantling of scaffolding.
   
     Note: Fall protection must be worn by workers erecting and dismantling scaffolds when exposed to falls greater than 6 feet.
   
4.1.2      Personnel working on a scaffold platform with full handrail, mid rail, toe boards and gated access are not required to tie off when working inside the platform area. Safety harness shall be used during scaffold erection. Tie off is required above 2m (6' feet).
   
4.1.3      Personal protective equipment must be used which has been identified through the Workplace Risk Assessment/Job Safety Analysis.
   
4.1.4      Scaffolds shall be built or dismantled in a manner to prevent passage from under t
he scaffold. Caution tape should be used to mark a safe zone around the scaffolds. Personnel access through mid rails and cross bracing is not recommended.
   
4.1.5      If a scaffold erection interferes with the permanent access ladder or permanent fall protection device, alternative fall protection and ladder access must be provided.
   
4.1.6      Special precautions shall be taken to protect scaffold structure including any wire or fiber ropes when using a heat producing process.
   
4.1.7      Falling objects protection must be installed to provide protection from falling hand tools, debris, and other small objects. This can be accomplished by using toe boards, screens or brick guards; guard rails systems, nets, catch platforms, or canopy structure methods. These systems must be capable of containing or deflecting falling objects. Overhead protection shall be provided for individuals working on a scaffold exposed to overhead hazards.
   
4.1.8      Individuals shall not work on scaffolds during a storm or high winds. Every effort should be made to exit the scaffold prior to electrical storms. Scaffolds should only be sheeted in where the scaffold structure (including ties and/or raking shores) has been specifically designed to accommodate the additional wind loads that this imposes.

4.1.9      Individuals shall not work on scaffolding, which is covered with ice or snow, unless all ice or snow is removed and planking is covered with antiskid material to prevent slipping. This is because the deadweight of ice and snow can lead to significant overloading of the scaffold structure.
     
4.1.10      Tools, materials, and debris shall not be allowed to accumulate in quantities to cause a hazard.
     
4.1.11      Partly erected/dismantled scaffold must have suitable warning signs posted in pr
ominent locations, be barricaded off, or policed to prevent unauthorized entry. The use of Scaffold tags is strongly recommended.
     
4.1.12      When scaffold material is stored on-site, it is advisable to store the material under dry conditions.
     
4.1.13      Scaffolds are not to be placed closer than 9m (30' feet) to live power lines, or no closer than the minimum clearance specified by the National Electrical Safety guidelines in the country of jurisdiction. In some countries grounding of the scaffold structure is required.
     
4.1.14      Scaffold accessories shall be used and installed in accordance with manufacturer's recommended procedures. Accessories shall not be altered in the field.
     
4.1.15      Personnel who perform work on scaffolding systems must be trained according to the requirements outlined by Air Products or according to national or local regulations. R
etraining is required in at least in the following situations:
     
4.1.15.1      Where changes at the worksite present a hazard about which any employee has not been previously trained.
     
4.1.15.2      Where changes in the types of scaffolds, fall protection, falling object protection, or other equipment present a hazard about which an employee has not been previously trained.
     
4.1.15.3      Where inadequacies in an affected employee's work involving scaffolding indicates that the employee has not retained the requisite proficiency.
     
4.1.15.4      Where changes to the procedure have taken place, which an employee has not been previously trained.
     
   Note:  The Following Environmental Considerations:
     Metal scaffold platforms should be used during Lead Abatement Activities whenever possible, to eliminate contamination and cleanup of wood walk boards.
     
4.2      Scaffold Inspection
     
4.2.1      Scaffolding shall be inspected by a competent, qualified and certified scaffold inspector prior to use, after any modification, or after any occurrence which could affect the integrity of the scaffold structure. This shall either be the contractor responsible for the provision of the scaffold or an Air Products employee trained in the proper erection, inspection and use of scaffolding. The results and periodic frequency of such inspections shall be recorded and Scaffold Tags posted in a prominent location at each access point to show the inspection status of the scaffold and next inspection period.
     
     The periodic frequency shall depend on factors such as the type of scaffold, site and we
ather conditions, intensity of use, age of the equipment, and how often sections or components are added, removed or changed, but should never exceed 1 week (7 days). These kinds of factors will determine how quickly or how slowly safety related faults, loose connections, degradation and other defects could be expected to develop, and consequently indicate whether inspections should be conducted more frequently than every 7 days.
     
4.2.1.1      For routine maintenance activities, all scaffolding shall be inspected daily or before each work shift.
   
4.2.1.2      For Construction and Turnaround Activities, all scaffolding shall be inspected at least once before each work shift or more periodic as determined by the scaffold inspector.
   
     Note: "Periodic" means frequently enough so that, in light of these factors and the amount of time expected for detrimental effects to occur, there is a good likelihood that pro
blems will be found before they pose a hazard to working individuals.
   
4.3.2      Upon completion of a scaffold, the scaffold inspector shall inspect the scaffold. When a scaffold is approved by the inspector a green 'SCAFFOLD COMPLETED' - 'READY FOR USE' or a yellow 'No Access' tag will be inserted into the danger tag holder. If it is not approved, the inspector will attach a red tag into the danger tag holder indicating that the scaffold is not suitable for use. The red tag must remain in place until the scaffold is repaired and inspected by a competent person
   
4.3.2.1      The Inspector will date and sign the "GREEN" tag when there are no defects in scaffold construction noting total working load on tag.
   
4.3.2.2      The Inspector will date and sign the "YELLOW" caution tag and fill in any restrictions or cautions associated with the scaffold noting the total working load on tag.
   
4.3.2.3      The Inspector will date and sign a "RED" tag indicating that the scaffold is not to be used because it is being modified or is not suitable for people to be working on it.
   
4.3.3      No unauthorized modifications will be made to any scaffold. Only approved scaffold builders are permitted to modify a scaffold.
   
4.3.4      Scaffolding that is required to support a load must visibly display the maximum load permitted and all persons using the scaffold must be informed of the restrictions of use for the particular arrangement (load capacity, general access, inspection only, etc.). The sign should be legible and written in the native language to ensure full understanding. In some cases, dual language signs may be necessary.
   
4.3.5      Scaffolds shall be rated for total working load at time of inspection. To determine total working load, multiply length times width to find the square feet of the working area. Multiply working area by allowable load per square foot.
   
     Example: 1.5m (5' feet) wide by 2.1m (7 feet) long, 1.5m X 2.1m = 3.15 square meters (5'x7' = 35 square feet). Multiply this number 3.15 (35) times the working load per square meters (square foot) from the load chart found in OSHA's 1926 Subpart "L " or equivalent to find the total working load.
   
     Note: The Lumber basis for this is "Douglas Fir".
 
     Example: Full thickness undressed lumber
     Working load 22.7 Kg-per square meter (50 lb-per square foot)
Permissible span 2.4m (8' feet).
3.15 meter squared X 22.7 Kg per squared meter = 71.5 Kg -Total working load  (35 square feet x 50 p.s.f. = 1,750 pounds Total working load).
   
     Example: Nominal thickness lumber (dressed)
     Working load 11.1Kgs per square meter (25Lbs per square foot)
3.15 meters squared X 11.1 kgs per squared meter = 35 Kgs -Total working load (35 square feet x 25 p.s.f. = 875 pounds - Total Working Load)
   
     NOTE: FOR PERMISSIBLE SPAN - USE THE NEXT HIGHER NUMBER FOR
     LENGTH OF SPAN.
   
4.3.6      The minimum permitted widths for scaffold are as follows (unless specified by national regulations):
     

General
For men and materials
For supporting another platform
For the side of a sloping roof


4.3.7      Scaffold boards are to be supported as follows (unless national regulations are more stringent):
     
Thickness of board
      Maximum Spacing

51 mm      (2 in)      2590 mm      (8 ft)

4.3.8      Scaffold planking shall be scaffold grade as recognized by grading rules for the species of wood and stamped on the plank.
     
4.3.9      When a scaffold is built around a line or object, the following guidelines are to be followed:     

4.3.9.1      Toe-board shall be installed around the object.
     
4.3.9.2      Planking shall be covered with plywood 15.87 mm (5/8" inches) or greater and capable of supporting the intended load.
     
4.3.9.3      Scaffolds shall be planked end-to-end on each side of the object. The planking needs to be supported around the object to ensure the decking or planking will sufficiently hold the intended weight of people and tools and materials.
     
4.3.10      All brackets shall be seated correctly with side brackets parallel to frames and end brackets 90° to the frame. Brackets shall not be bent or twisted from normal positions.
     
4.3.11      Scaffolds shall be visually checked by the user prior to use to ensure that no unauthorized changes have been made and that the status tag is still valid. If the tag is not valid, the scaffold shall be removed from service by removing the scaffold tag until repairs a
re made and the scaffold has been re-inspected. A red tag should be fixed to the scaffolding indicating no one is to use it.
     
4.3.12      Where gin wheels/pulleys (including ropes) or other accessories are fitted to the scaffold, these are to be included into the scope of all inspections mentioned in this procedure.
     

4.3.13      When it is proposed to use a lightweight mobile scaffold platforms for light duty work, the scaffold shall be subject to the following:
     
4.3.13.1      The scaffold is used with all bracing and outriggers in position and wheels locked.
     
4.3.13.2      All scaffold is used on level firm ground only.
     
4.3.13.3      All points of the scaffold are fully supported by the ground.
     
4.3.13.4      The individuals erecting the scaffold have been properly trained in its use.
     
4.3.13.5      The height of the scaffold shall not exceed the smallest base dimension by a factor greater than 3:1, subject to the manufacturer confirming that the scaffold is suitable for this and that the manufacturer instruction and information are available. If no information exists, assume 2:1 as the maximum ratio. Additionally, the smallest base dimension shall not be less than 1200 mm (4' feet).
     
4.3.13.6      Ladders must not be used to extend the height of the scaffold.
     

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