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Scaffolding in New Zealand - Best Practice Guideline for

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SECTION 2: SAFETY IN SCAFFOLDING - Continued

2.8 Hazard identification and management: Continued

2.8.3 Hazards from the environment in which the scaffold is situated

Often the scaffolding site and its environs create as many hazards as the work itself.

2.8.3.1 General construction work
Hazard:

Personal injury caused by fall of equipment. Possible conditions leading to this situation include:

  1. Working in the vicinity of cranes or loads being lifted by cranes.
  2. Working underneath, adjacent to, or above building openings.
  3. Working underneath or above other trades people.
Control:
Hazard:

Personal injury caused by contact with compressed air.

Many sites make extensive use of compressed air e.g. to power concrete breaking equipment. If used incorrectly compressed air can cause serious injury or death. Conditions that can lead to this situation include:

  1. Debris or splinters blown into eyes or skin.
  2. Contact with compressed air on bare skin can lead to air embolisms, i.e. a bubble of air entering the bloodstream - often causing death.
  3. Incorrect or faulty fittings on air hoses which can fail under pressure. This can lead to air hoses moving wildly and coming into contact with workers.
Control:
Hazard:

Personal injury caused by contact with live electrical conductors or equipment.

Many sites use temporary power supplies which, if used incorrectly, can be dangerous. Electric shock or arcing can lead to severe injuries or even electrocution (death).

Control:
Hazard:

Personal injury caused by person falling.

Construction sites are inherently dangerous places to work and due to the unfinished nature of the area have many trip or fall hazards. These may include:

  1. Obstructed walkways.
  2. Trip hazards obscured by poor lighting.
  3. Floor openings left with no covers or guardrails in place.
  4. Poor access to upper or lower floors.
  5. Wet or slippery walkways.
Control:
Hazard:

Personal injury caused by crushing from moving machinery.

Construction sites often make use of excavation machinery, hoists, cranes and other mobile plant. This type of equipment can be hazardous if used incorrectly and if safety procedures are not followed.

Control:
Hazard:

Personal injury due to inhalation of fumes or asphyxiation.

Sometimes on construction sites, personnel are required to operate in confined spaces. These areas are normally subject to poor ventilation and can become filled with fumes from machinery or processes being carried out on site.

Control:
Hazard:

Personal injury caused by fire.

Fire is always a potential hazard on construction sites. Make every effort to avoid it.

Control:
Hazard:

Personal injury due to collapse of falsework, propping or formwork systems.

Construction sites often make considerable use of falsework, propping and formwork systems. A collapse of one of these systems can lead to serious injury or death.

Conditions that can lead to this situation include:

  1. Unsuitable foundations.
  2. Overloading of equipment.
  3. Inadequate bracing or ties.
  4. Poor design.
  5. Unskilled operators.
  6. Unauthorised tampering or interference with equipment.
  7. Equipment in poor condition.
Control:
Hazard:

Personal injury due to exposure to welding, grinding or gas cutting, operations.

This type of work produces heat, sparks and possibly infra-red rays (the cause of "arc eyes"), hazards associated with fumes and the possibility of falling equipment.

Control:
Hazard:

Personal injury due to being struck with projectile from powder powered tools or a nail gun.

These tools make use of either explosive cartridges or compressed air to drive a nail or pin into concrete, steel or timber. Consequently the projectile can have the same effect as a bullet fired from a gun. Any body part struck by the nail or pin will suffer at least a puncture wound and possibly other serious injuries.

Control:
2.8.3.2 Demolition work

Demolition work could be viewed as the direct opposite of construction work. However, when the two industries are examined they have similar hazards. For example, both have hazards due to possible exposure to:

  1. Falling equipment or material.
  2. Compressed air.
  3. Gas cutting and or welding and/or grinding.
  4. People falling.
  5. Moving machinery.
  6. Fire.
  7. Live electrical conductors or equipment.
  8. Failure of temporary propping systems.
Hazard:

Injury to feet and hands due to contact with timber with exposed nails.

Demolition work can lead to large amounts of timber being removed from buildings often with nails or screws exposed. This can lead to puncture wounds in hands or feet when dealing with such material.

Control:

All personnel working in the vicinity of timber with protruding nails should wear safety boots and gloves and take all steps to avoid coming into contact with the nails. In the case of an abrasion or puncture wound being sustained, the injury shall be treated immediately with the use of antiseptic and a suitable bandage. The injury must be reported to the supervisor and if necessary further medical treatment must be sought.

Note: There is always a possibility of contacting tetanus or having the wound turn septic if not treated properly. If in doubt seek medical advice.

Hazard:

Personal injury due to scaffolding collapse caused by scaffolding support structure being demolished and suitable alternative ties not being put in place.

In the normal course of events scaffolding will be erected on a construction site as the building progresses or when the building superstructure is complete. This process ensures that the scaffolding can be safely tied as it is erected. In the case of demolition work it is the opposite. Often a scaffolding structure that is being used to assist with the demolition of a building will be completely erected around the structure and then as the building is demolished the scaffolding is progressively dismantled. There have been occasions where scaffolding has collapsed on demolition work due to being left exposed too high above the last tie off points. This can lead to major damage and serious injury.

Control:
Hazard:

Personal injury caused by crushing due to building collapse.

There are several methods used for the demolition of a building. Some are relatively passive such as brick by brick demolition used with some buildings with historical significance. Some are volatile such as the use of explosives or progressive deliberate collapse (felling) of the structure. In the case of the latter there is a real danger that the collapse of the building could become uncontrolled or happen prematurely, possibly trapping workers inside and causing serious injury.

Control:
2.8.3.3 Work near asbestos
Hazard:

Personal injury due to exposure to asbestos.

Although the risk of exposure to asbestos has been greatly reduced over the last decade, occasionally workers involved in the construction industry will be on a site where asbestos products have been located e.g. refurbishment projects. Most responsible building owners have taken steps to reduce or eliminate these products or alternatively have covered or sealed them so as to reduce the possibility of the release of the fine dust or fibres that can cause asbestosis or other related injuries.

In the demolition industry, workers are more likely to be exposed to the problem of asbestos removal and containment and as such special precautions are required. In some older buildings, asbestos was used for insulation and/or fire proofing as well as a building material for roofing and wall cladding.

The greatest hazard from cladding type products comes when the material is in a dry or cracked condition or is being cut for the purpose of removal. Similarly, hazards exist when insulation or fireproofing material is being scraped off surfaces. The concern is the release of asbestos particles which can lead to medical problems if inhaled.

Control:
2.8.3.4 Work on ships, offshore installations and bridges

When scaffolding work is required in these areas most of the hazards already covered will need to be managed for example:

  1. Hazards associated with the use of cranes and other lifting equipment and moving machinery.
  2. Hazards associated with work in confined spaces.
  3. Possible hazards associated with the risk of fire.

In addition to these (and many others) there are the unique hazards associated with work over water.

Hazard:

Personal injury due to fall from height into water.

Workers erecting or dismantling scaffolding over the side of a ship, rig or bridge have the added difficulty of trying to carry out their task in a void situation whereby they cannot work from a readily accessible platform.

Control:
2.8.3.5 Work in chemical plants, factories, storage areas and processing facilities

Maintenance work carried out in these areas can be particularly dangerous due to the processes carried out and also because of the goods produced or stored in them.

Hazard:

Personal injury due to exposure to heat.

Many plants of the type described above have processes that can produce large amounts of heat. Examples include steel mills, smelters and petrochemical plants with reformers.

The two main hazards associated with work adjacent to heat are:

  1. The possibility of burn injuries; and
  2. The possibility of dehydration and heat sickness.
Control:
Hazard:

Personal injury due to exposure to cold.

Some processing and storage plants make use of refrigeration areas. The degree of cold is dependent on the product being manufactured or stored; however all areas with more than mild refrigeration should be treated as hazardous and precautions must be taken to prevent hypothermia or other cold related injuries.

Control:
Hazard:

Personal injury due to exposure to excessive noise levels.

Many plants make use of machinery or equipment that produces noise in excess of recognised safe exposure thresholds. Prolonged exposure to excessive noise can lead to hearing loss and stress related problems. In general terms a 'high noise area is any area where you cannot communicate to another person 600mm away from you without raising your voice.

Control:
Hazard:

Personal injury due to explosion/s in a work area.

Many plants and storage facilities produce or handle volatile materials that in particular circumstances can become explosive. For instance petrochemical plants produce highly flammable liquids and gases and chemical plants can produce similar substances. Other plants can manufacture products that at first can appear to be relatively harmless but in the wrong condition or atmosphere (or when mixed with other material) may also become unstable or potentially explosive. Examples of products that are highly flammable are methanol, petroleum, CNG, LPG etc.

Dust explosions can also be problematic. A dust explosion will normally occur in a confined space such as a silo or vessel and is actually two explosions that occur simultaneously. The first can be a minor one caused by a spark or exposure to a heat source. This will ignite a small quantity of material and cause a shock wave. This shock wave will hit the wall of the vessel causing the release of more dust into the already heated atmosphere. A second explosion will now occur due to the larger fuel source, oxygen rich atmosphere and heat source. Examples of products that are known to be involved in particle or dust explosions are coal, sawdust, flour, wheat, coffee and aluminium. As mentioned above on the surface these items appear to be unable to cause much harm, but when these products are stored or being transported there is likely to be dust build up.

Control:
Hazard:

Personal injury due to exposure to toxic chemicals, gases or caustic products.

Some plants and storage areas produce or handle substances that can be hazardous either by themselves or when mixed with others or when the composition is changed, for example in the case of a fire in the area. The degree of harm caused by chemicals and gases will depend on the toxicity of the substance, the exposure to it and sometimes the method in which it enters the person.

While gases are inhaled, chemicals can be dangerous in a variety of ways. Some chemicals produce fumes that may be inhaled. Some can be swallowed (ingested) e.g. if a person was working with chemicals without gloves and then failed to wash their hands before eating a small quantity may be passed from the hands to the food to the person. Some chemicals can enter through the skin, either through absorption or by entering a puncture wound or open exposed cut. Organo-phosphates are an example of a chemical that can be relatively harmless if exposed to the skin or alternatively there are some types whereby even a small amount on the skin can be deadly.

Chemical fumes and toxic gases can present similar hazards to explosive gases in that they can accumulate in confined spaces. Some are heavier than air and can build up in pits or ducts or other underground areas. Some are lighter than air and similarly can build up in ceilings or roof cavities.

Control:
Hazard:

Personal injury due to exposure to radiation

Some plants make use of radiation producing equipment as part of their processing. The amount of potential exposure with will depend on the type and intensity of radiation produced. An example of a hazard to personnel posed by radiation may be staff working around X-ray equipment e.g. in the medical and non-destructive testing industries. Prolonged exposure to this type of equipment can lead to medical problems.

Control:
2.8.3.6 Work on roof areas
Hazard:

Personal injury due to a fall from or through a roof area of staff or materials. There are many times when working on a roof could be hazardous, for example:

  1. A slip on a roof could lead to sliding off an unprotected edge and falling.
  2. A slip could lead to the release of equipment, leading to it falling and posing a danger for personnel below.
  3. A person working or walking on a brittle roof may stand on a weak area and fall through posing a danger to themselves and other people below. Similarly equipment dropped onto a weak section could also penetrate the area.
Control:
2.8.3.7 Work near power lines
Hazard:

Personal injury due to electric shock from contact with power lines.

For instance this can occur when:

  1. Homes that require painting need scaffolding to be erected in order to gain access to high areas. Workers involved in the erection and dismantling of scaffolding to these areas (and any others with exposed power lines) risk electric shock or death by electrocution caused by contact with wires.
  2. Excavation work uncovers underground power lines causing unexpected contact.
  3. Personnel using mobile scaffolding, cranes, Hiab trucks and other mechanical plant are unaware of overhead power lines and move parts of the equipment so as to cause contact with the lines.
Control:
2.8.3.8 Work outdoors
Hazard:

Personal injury due to over exposure to ultra violet radiation.

In recent years over exposure to the sun has been associated with a variety of medical problems from temporary pain caused by sunburn to skin cancers like melanomas. Many of the serious disorders may not be apparent for a number of years and then can cause major problems and in some cases death.

Control:
Hazard:

Personal injury due to exposure to high wind conditions.

Work should only be carried out in high winds if it is safe to do so. A hazard analysis should be completed to determine this. For example high wind conditions can lead to:

  1. Personnel working aloft losing their balance and falling.
  2. Personnel working aloft, losing control of equipment.
  3. Dust and debris blowing around and possibly entering the eyes.
  4. Loss of control of crane lifted material.
Control:
2.8.3.9 Work near roads and heavy traffic areas

Occasionally scaffolding will be required in high risk areas such as motorways, (for bridge repairs or construction) or adjacent to other places with heavy traffic flows, such as on footpath areas next to roadways. Any vehicle movement can be the source of many hazards and personnel involved in work around these areas must take all precautions to ensure their own safety and that of others in the area. Refer to Transit New Zealand Code of Practice and/or any local authority requirements

Hazard:

Personal injury due to vehicle colliding with scaffolding.

"The main cause of accidents at road works is inadequate signposting and lighting and drivers failing to notice road workers" (DOL Guidelines for the provision of facilities and general safety in the construction industry). This can apply equally to scaffolders carrying out operations on or near roadways. If a vehicle were to collide with a scaffolding structure the consequences could be severe.

Control:
Hazard:

Personal injury due to vehicle colliding with personnel or pedestrians.

When scaffolding work is being carried out above pedestrian areas adjacent to traffic flows, the scaffolding crew is responsible not only for ensuring their own safety but also the protection of other people in the area. In order to prevent possible harm to others that could be caused by falling objects, personnel will normally erect some form of barrier to prevent pedestrians from entering the area below the operations. In areas limited by space, this may necessitate diverting them onto roadways. This situation can be very dangerous and could lead to people being run over or knocked down.

Control:
Hazard:

Personal injury due to drivers becoming distracted and colliding with other vehicles.

A major hazard involved with work near roadways is that drivers can become distracted by operations being carried out on the side of the road and lose concentration. This can lead to drivers losing control of the vehicle or colliding with other vehicles.

Control:
2.8.3.10 Work near others under the influence of drugs or alcohol or acting irrationally
Hazard:

Personnel under the influence of drugs or alcohol can be operating with impaired judgement. This can lead to a loss of concentration, which in certain areas can be dangerous or even fatal.

Similarly, people carrying out practical jokes or acting irrationally on a work site can sometimes under estimate the effect of their actions and cause severe harm to other personnel and themselves.

Control:
2.8.3.11 Work in dirty areas
Hazard:

Personnel exposed to dirty work conditions can develop infections in existing or new wounds if care is not taken. Similarly, diseases such as hepatitis can be spread through failure to ensure personal hygiene.

Control:

2.8.4 Hazards associated with the use of scaffolding

Most accidents that occur from use of scaffolding platforms can be attributed to one or more of the following factors:

  1. Impatience of the user.
  2. Unqualified personnel altering the scaffolding.
  3. Poor design or construction of scaffolding.
  4. Overloading of the structure.
  5. Removal of built in safeguards.
Hazard:

Personal injury due to unqualified personnel altering the scaffolding.

Often on a work site a scaffold will need altering. If an unqualified or inexperienced worker carries out alterations to a structure there is a risk that they will lose control of the equipment or remove or loosen a vital part of the structure and not replace it. Both of these situations are dangerous and can lead to serious injury.

Control:
Hazard:

Personal injury due to collapse of structure due to poor design or construction or overloading of the scaffolding structure.

Poorly designed or constructed scaffold structures could be subject to collapse if exposed to adverse conditions. Similarly structures that are overloaded by stacked materials, large numbers of personnel using them, or environmental conditions, could collapse.

Control:
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