SECTION 2: SAFETY IN SCAFFOLDING - Continued

2.8 Hazard identification and management

The scaffolding industry has long put its workers in hazardous situations to provide safe working areas for other trades and end users of scaffolding structures. The following list shows hazards that have been identified and the controls that need to be implemented in order to provide a safer working environment for scaffolders. This list is not intended to be comprehensive and new hazardous situations will arise that will require new initiatives and controls. This is therefore a reference guide only. Companies and individuals using this list should view it as a base from which to start their own hazard management programme. Appendixed in the final section of this document is a sample sheet that can be used to identify and control hazards - the Hazard identification and controls report.

When assessing hazards associated with scaffolding these can be categorised in one or more of the following areas:

1. Hazards associated with the design of the scaffolding.
2. Hazards associated with the construction of the scaffolding.
3. Hazards associated with the environment in which the scaffolding is situated.
4. Hazards associated with the use of the scaffolding.

2.8.1 Hazards associated with the design of the scaffold

A significant hazard associated with scaffolding is the collapse of the structure. This has the potential to cause multiple fatalities, both to people using the scaffolding and to others who may be in the area. Structure failure can be avoided firstly by identifying hazards and then implementing controls through the design of the scaffold.

2.8.1.1 Foundations

Hazard:

Substandard foundation collapses and causes failure of structure.

Control:

• All scaffolding must be erected from suitable foundations
• Bearing areas underneath standards must be:
  1. Level.
  2. Compacted.
  3. Capable of taking all imposed loads - dead, live and environmental.
• All foundations must be stable against subsidence.
• Suitable bearing material such as soleboards and baseplates must be used. Inadequate bearers such as concrete blocks, bricks, undersized timbers must not be used.
• In the case of a sloping foundation additional bracing at the base of the scaffolding may be required.
• In the case of hanging or cantilevered scaffolding the supporting structure must be capable of withstanding all imposed loads.
• Always, if in doubt, seek expert advice such as from a chartered engineer.

2.8.1.2 Standards and ledgers

Hazard:

Incorrect design and construction of standards and ledgers leads to failure of the structure.

Standards and ledgers are load bearing members connected by load bearing couplers. Couplers are tested and have a known load bearing capacity when used in a right angle configuration (unless especially designed, such as swivel couplers). Right angle (90°) couplers can fail if standards and ledgers are not square. Incorrect joining of standards and ledgers can also lead to failure of the structure. Incorrect construction of the standards, i.e. floating standards, can lead to uneven bearing on the foundations and can also cause failure of the structure. Standards and ledgers that are erected with over-sized spans can also lead to over-stressing of the structure and possible failure.

Control:

• All standards must be erected so as to be vertical; all ledgers must be erected so as to be horizontal. If in doubt these members can be checked by the use of a spirit level. Maximum tolerance normally specified is + or - 5 degrees.
• All joins in standards and ledgers must be in the correct position and must be made with the appropriate components.
• Internal joint pins are not rated for tension loads and must not be used in ledgers if possible.
• All standards must bear firmly against baseplates.
• All standards and ledgers must be constructed with the appropriate span for the duty loadings of the scaffolding.

2.8.1.3 Decking

Hazard:

Personal injury caused by inadequate decking.

Serious injuries from scaffolding have been caused by inadequate decking, including:

1. Too narrow working platform for men and materials.
2. The use of substandard equipment.
3. Incorrect spacing of transoms causing trap ends or poor bearing area on planks.
4. Unsecured decking.
5. Insufficient transoms or over length spans causing over-stressing of planks.

Control:

• All scaffolders erecting working platforms must be aware of the intended (or any other possible) use of the scaffolding. Consideration must be given to the number of personnel and any materials that will be stacked or stored on the platform (live load).
• All decking must be suitable for the intended purpose in terms of width, length and height.
• All transoms must be of the correct length (no transom is to have a joiner inserted in the span) and must be suitably spaced to provide adequate support for the end use of the platform. Also the planks must be supported correctly at the ends.

2.8.1.4 Access and egress

Hazard:

Personal injury due to inadequate access and egress.

Inadequate access to and from working platforms can lead to falls and serious harm. Conditions that can lead to this situation include the following:

1. Unsuitable foundation for the ladder.
2. Unsecured ladder.
3. Equipment in poor condition.
4. Incorrect placement of the ladder (inclined angle).
5. Wrong size ladder.
6. Incorrect use of the ladder.
7. Unprotected ladder openings.

Control:

• All ladders must be founded on a level base. All ladders must be secured.
• All ladders must be in good condition and must be free from defects. All ladders must be positioned at the correct angle and must be placed so as to be suitable for access to the required area.
• All ladders must extend a minimum of 1.0m above the working platform, unless adequate guardrails surround the ladder opening.
• All personnel climbing the ladder must face the ladder and use both hands. At no time should equipment be carried up the ladder.
• During busy periods personnel must wait until the ladder is clear before ascending or descending.

2.8.1.5 Edge protection

Hazard:

Personal injury due to inadequate edge protection.

A potentially dangerous situation exists when a person works at height without suitable edge protection. Hazards include the fall of personnel and/or material.

Control:

• All platforms must have suitable guardrails, kickboards and, if required, screening.
• Guardrailing must be positioned on the outside and ends of every working platform or any face of the scaffold that is more than 300mm from the area to be worked on.
• Suitable barriers must be provided to prevent accidental falls through ladder access, deck openings and building facade penetrations.
• All scaffolding must be fitted with guardrails to both ends of the platform.
• Where oversize planks are used on a platform, suitable barriers must be erected so as to prevent personnel standing on trap ends.

2.8.1.6 Stability against overturning

Hazard:

Personal injury due to unstable scaffolding falling.

If a scaffold is erected with too narrow a base there is a risk of the structure overturning. Similarly, if scaffolding is erected with insufficient or inadequate ties then it could collapse if exposed to too much force. Conditions that could cause this situation include:

1. Incorrect base to height ratio for free standing scaffolds.
2. Incorrect base to height ratio for tower scaffolding exposed to high wind loads.
3. Mobile scaffolding being used with unlocked wheels.
4. Insufficient ties for the imposed loads.
5. Inadequate ties.
6. Failure of the supporting structure.
7. Incorrect position of ladder accesses to free standing or mobile scaffolding.
8. Increased environmental loadings due to shade cloth.

Control:

• All free-standing scaffolds must be erected with the correct base to height ratio for the site conditions. This can be achieved through a variety of methods e.g. using raking tubes.^[2]
• Consideration should be given to all expected live loads and environmental loads. If in doubt seek the opinion of a chartered engineer. All mobile scaffolding must have the wheels locked prior to work commencing on the platform.
• All ties must be capable of sustaining all expected imposed loads - dead, live and environmental. All ties must be fixed to adequate supporting structures. All ladder access for free-standing or mobile scaffolding should be internal, unless specifically designed.
• Where structures incorporate reveal ties these must account for no more than 50% of ties used. The balance need to be physical ties i.e. lip, lock off, box, or rigid ties.

2.8.1.7 Rigidity

Hazard:

Personal injury caused by collapse of scaffolding due to inadequate bracing

If a scaffolding structure is too flexible this can lead to loosening of the couplers and overloading of the equipment. Similarly if the platform is unstable a collapse or fall could occur.

Control:

• All scaffolding must be adequately braced in both the longitudinal and transverse planes.
• Occasionally the use of plan bracing may be required such as at the base of a mobile scaffold or where too great a span exists between tie points.

2.8.2 Hazards associated with erecting and dismantling scaffolding

Numerous hazards exist that relate to the construction and dismantling of scaffolding.

2.8.2.1 Loading of vehicles with scaffolding equipment

Hazard:

Personal injury due to manual handling of equipment. This can include back, hand and foot injury.

Control:

• All personnel to use correct lifting procedures. Lift with back straight and legs bent. Lift with load in centre of body.
• Never lift anything too heavy.
• All personnel to be provided with and use PPE e.g. hard hats and safety footwear.

Hazard:

Personal injury due to being crushed by moving equipment.

Equipment such as forklifts have various hazards associated with their use such as:

1. Poor visibility.
2. Overturning of the machine due to overloading, poor ground conditions or incorrect travelling procedure.

Control:

• All personnel using forklifts or other machinery must be suitably qualified. All care must be taken to avoid travelling into blind spots.
• All drivers must be aware of other people in the area.
• All loads must be secure while travelling and travel as close as possible to the ground with the forks either level or tilted back.
• All loads must be correctly centred.

Hazard:

Personal injury due to fall of equipment from a truck.

Control:

• All equipment must be loaded and transported in the correct manner. Tube must be stacked against restraints.
• Couplers must be bagged or transported in cages.
• Planks must be loaded onto dunnage or laid flat in the case of hand loading.
• System scaffolding must be transported in stillages, pallets or cages, or the equipment must be suitably banded or strapped to prevent movement.
• All equipment must be secured with the appropriate straps or tie downs. All load-binding equipment must be in good working order.
• No trucks are to be overloaded in terms of height or weight.
• In the case of crane loading of equipment, all slinging must be carried out by suitably qualified personnel.
• All cranes must be operated by qualified personnel.
• Only one person to give directions to crane driver.
• All cranes to be set up by the correct method on adequate foundations. No crane should exceed lift limits or be used to drag equipment.

2.8.2.2 Erection and dismantling of the structure

Hazard:

Personal injury due to fall of equipment.

There are several factors that can cause this hazard such as:

1. Incorrect handling of equipment.
2. Incorrect stacking of equipment.
3. Inexperienced workers.
4. Personnel standing underneath equipment being lifted or lowered.
5. Failure to barricade the working area.
6. Unauthorised entry of other personnel into the working area.
7. Failure to use protective equipment.

Control:

• All equipment must be handled in the correct manner - not thrown or dropped.
• No personnel to attempt to lift any equipment that is too heavy.
• When used gin wheels and ropes must be in good condition and properly secured.
• Correct knots, bends or hitches must be used.
• When equipment is being "handballed", proper communication and good visibility must be maintained between members of the chain. Lift or lower equipment from stable, safe positions i.e. behind guardrails, never from an open space.
• No personnel are to stand directly under equipment that is being lifted or lowered. Once equipment is released personnel must move out of the area or seek cover.
• All equipment must be stacked properly and in a tidy manner.
• All equipment must be kept away from exposed areas.
• No area of the scaffolding should be overloaded with surplus equipment.
• All personnel will be supplied with and must use personal protection equipment suitable for the task.
• All areas below scaffolding operations must be suitably barricaded and if required signs must be erected.
• Only personnel involved with the work will be allowed into the area.
• No access will be given to any scaffolding under construction or in the process of being dismantled.

Hazard:

Personal injury due to fall of people from scaffolding.

Although this is very rare in the industry it has been known to happen and the consequences can be severe, even fatal. This hazard can be a double-edged sword. Not only can a person be hurt by falling; there is also the risk that they land on somebody else causing multiple injuries.

Several factors can contribute to this situation such as:

1. Poor communication between workers.
2. Incorrect erection or dismantling procedures.
3. Poor housekeeping during erection or dismantling.
4. Inadequate safety procedures such as poor fall arrest systems or safety harnesses not being used in high risk areas.

Control:

• All personnel must be aware of the activities of others involved e.g. if a portion of scaffolding has been removed and this is not known, danger may be hidden.
• All scaffolding must be checked before dismantling, to ensure it is safe to proceed.
• All personnel must maintain communication lines.
• All scaffolding must be erected and dismantled using the correct procedures. As a general rule work must be completed as the work progresses.
  • Decking and guardrailing must be in place.
  • Ladders must be installed.
  • Ties and bracing must be put in place.
• All equipment not being immediately used must be stacked safely and tidily.
• All personnel must use appropriate safety equipment if required.
• Fall arrest systems must be regularly checked for defects.
• Static lines must be installed by qualified personnel and must be capable of sustaining all loads likely to be imposed on them.
• Fall arrest systems must be used in all void situations such as the erection and dismantling of cantilever scaffolding, hanging scaffolding, etc.
• Safety harnesses must be worn by all scaffolders working on scaffolds above 5m.
• Correctly secure and wear safety harnesses when operating a swinging stage.

Hazard:

Personnel injury due to defective tools and equipment.

This can include injury to hands, eyes, feet and serious body harm caused by:

1. Faulty spanners (which can slip or break).
2. Faulty hammers (which can splinter or shatter).
3. Defective electrical equipment.
4. Substandard planks.
5. Corroded tube.
6. Defective fittings or couplers.
7. Defective ropes and other lifting equipment.
8. Faulty or under strength personal protective equipment.

Control:

• All equipment used in the scaffolding must be in good condition and fit for its intended purpose.
• All defective equipment must be isolated and not used.
• Bent tube must be cut down or discarded.
• Faulty planks must be cut down so as to be safe or discarded.
• Faulty couplers and fittings must be serviced, repaired or discarded.
• Faulty tools must not be used.
• Faulty ropes must be cut down so as to be safe or be discarded.
• Gin wheels must be of solid construction and have a suitable wheel diameter.
• Gin wheels must be free turning and have an appropriate sheave size.
• Gin wheels must be able to be secured according to manufacturer's specifications or accepted industry practice.
• Gin wheels must not be overloaded and must be attached to an appropriately designed and constructed support. Note that additional ties may be required in the scaffolding in order to sustain the imposed load.
• Shackles used to secure gin wheels must be moused and prevented from movement along the support.
• All electrical equipment must be in good condition and regularly checked for defects.
• Electrical equipment, including leads, must be used with isolating transformers, earth leakage circuit breakers or RCDs. These must also be in good condition and regularly checked for suitability.
• All electrical equipment, including leads, must be checked by a qualified person a minimum of every 3 months. Each item must be tagged safe with the date.
• All electrical equipment and electrical installations on construction sites must comply with AS/NZS 3012 Electrical Installations - Construction and Demolition Sites. This required in Regulation 46 Electricity Regulation Compilation 2003.
• Any defective electrical equipment must be repaired by a suitably qualified person.
• All personal PPE must be in good condition and suitable for its intended purpose. Faulty PPE can lead to a false sense of security and must be discarded.

Hazard:

Personal injury due to fall from scaffolding caused by slippery equipment.

This can lead to a variety of injuries from moderate to severe. This could be anything from a slip from the bottom rung of a ladder causing a sprained ankle to a fall from height causing serious injury or death. In addition a person handling equipment could slip and release the gear leading to a hazardous situation for people below.

Control:

No personnel are to carry out operations at height on wet or slippery equipment. Any minor works that can be carried out within the confines of a safe working platform would be permitted, however all due care must be taken.

Hazard:

Personal injury caused by falling debris.

On many occasions trades people using scaffolding are oblivious to the hazard they can create by leaving debris or rubbish on scaffolding platforms. Welders often leave rod ends, slag, used grinding disks, etc. Plasterers, blocklayers and bricklayers often leave dried mortar or block off cuts. Carpenters often leave timber off cuts, nails, screws, etc. This material can cause serious harm if dislodged or dumped from height onto people below.

Control:

• All rubbish must be removed from scaffolding decking as soon as practical, ideally by the trades that caused it. Poor housekeeping is a cause of many incidents.
• When the scaffold deck is being lifted or dismantled all care must be taken to prevent dust and debris falling on people below.
• The area below the scaffolding must be barricaded and people kept out of the area.
• All personnel must use PPE such as hard hats, safety glasses and safety footwear.
• All tubes must also be checked for hidden debris. Welding rods, screwdrivers and other small items can become missiles if released through a tube.

---

Footnotes

^[2] Raking tubes must be attached with load bearing couplers and be braced back to the scaffold. Swivels, while not recommended, can be used.

---