Falls from height kill and injure more people in construction than anything else.

In the 1999/2000 year, 14 of the 17 deaths in construction were from falls from height, making our death rate amongst the highest in the western world!

The Importance of Planning Ahead

Planning is vital before you begin working at height. One planning tool is to use a Task Analysis with your employees. Simply:

1. EXAMINE PROJECT ACTIVITIES
2. IDENTIFY TASKS FOR EACH ACTIVITY
3. DEVELOP SPECIFIC CONTROLS FOR EACH HAZARD
4. IMPLEMENT SPECIFIC CONTROLS
5. MONITOR CONTROLS FOR EFFECTIVENESS

The Control Hierarchy

When you have to work at height, there is a simple process that needs to be followed to decide what is the safest way to carry out the work.

Use the Control Hierarchy to firstly try to eliminate the hazard. If this is not possible you must then isolate the hazard. If this step is not possible, then only as a last resort you must minimise the hazard.

Eliminate

Section 8 - HSE Act: Significant hazards to employees to be eliminated if practicable.

Ask yourself: How can I remove the hazard from the work altogether?

Elimination must always be your first step, and if there is a practicable step to do this it must be done.

This may mean changing the work process or method to remove exposure to the height hazard, which could mean carrying out much of the work at ground level.

In the photo, the roof was constructed on the ground and is being craned into place. While this doesn't remove every hazard, it has removed a major fall hazard by removing a lot of the need to work at height.

Roof being craned into position

Isolate

Section 9 - HSE Act: Significant hazards to employees to be isolated where elimination impracticable.

Ask yourself: How can I separate the hazard from myself and any other worker?

This is not the first option. First you must always try to eliminate the hazard. Only when elimination is not possible should the employer take all practicable steps to isolate the hazard from employees.
The important words are 'isolate it from employees'. This means preventing the employee coming into contact with the height hazard.

This could be done by erecting a scaffold around the exterior of the structure to an adequate height to act as full perimeter edge protection, or using a roof edge guardrail system as shown in the photo.

Roof edge guardrail system

Minimise - the last resort

Section l0- HSE Act: Significant hazards to employees to be minimised and employees to be protected, where elimination and isolation impracticable.

Ask yourself: What can I do to minimise the possible consequences should an incident occur?

Minimisation is the last resort. Only when you cannot either eliminate or isolate the hazard should the employer take all practicable steps to minimise it.

Minimisation is like the ambulance at the bottom of the cliff. We tend to consider it first as it is often the simplest option. But employers need to be able to demonstrate the process they have gone through to first try to eliminate or isolate the hazard.

Minimising the height hazard might involve the employer providing personal protective equipment (a safety harness for example) to protect an employee should a fall happen.

Remember to monitor your employee's exposure to the hazard.

Minimising a hazard by using a fall arrest or travel restraint system should always be your last resort. These systems require a high level of training to both set-up and use. Only use them if you have been fully trained and emergency rescue procedures are in place.

Fall Arrest and Travel Restraint Systems

The use of fall arrest harness or travel restraint systems is not a preferred method to protect workers when working at height.

OSH, ACC and Site Safe strongly advise that these systems should only be used as a last resort when working at height as they have severe limitations.

Some of these limitations include:

• Both systems require high levels of training and supervision to ensure their safe set up and use
  
• It is difficult to find or design anchor points that will have adequate strength - in many cases anchor points aren't even available
  
• Where anchor points are available, written evidence (a specification from the manufacturer, or a statement from an engineer) needs to be supplied stating that individual anchorage points will withstand the required load
  
• The ideal location for anchor points is directly above head height - this is not possible when working in many situations
  
• Ropes and lanyards can easily become tangled or snagged on obstructions on structures
  
• Systems require substantial clearance between the working level and the ground to ensure the user still doesn't hit the ground in the event of a fall
  
• Also in the event of a fall, rescue must be immediate as blood circulation problems can lead to brain damage or death in minutes (if less than two workers are located on site, these systems should simply never be used).

Wherever feasible an enclosed work environment, where it is impossible for workers to fall through or off a structure, should be provided.

More Information

For more information on working safely at height, contact:

• www.osh.dol.govt.nz
• or phone your local OSH office
• www.acc.co.nz/injury-prevention
• or phone 0800THINKSAFE (0800 844 657)
• www.sitesafe.org.nz
• or phone (04) 381 3885