Working at height has been a leading cause of serious and fatal accidents for many years. It is essentially impossible to eliminate the need to work at height, so focus and emphasis needs to be placed on managing this risk.

Let’s clear up some common misconceptions first.

Working at height does not mean you have to be above the ground. The definition of what constitutes working at height was changed to include scenarios where someone is working at ground level but next to an excavation or a drop in level. So you can fall from the ground to a lower level, this is also considered to be working at height.

The notion that working at less than 1.8 meters (or 6 feet) is safe and does not require any special precautions is not correct. This was a historical detail that used to be enshrined in some former legislation. It was based on the idea that if a person fell less than 6 feet then the consequences were less likely to be fatal or serious. So even if statistically this is true, it begs the question of how many serious or fatal accidents are acceptable? The answer of course has to be “none”. I can recall investigating a fatal accident to an electrician who was working on a doorstep, so no more than 20 to 30 cm above ground level, he tripped and fell, struck his head and unfortunately passed away. The point of this case is not to say that I would have expected to see edge protection when working on a doorstep, it is rather to dispel the notion that there is such a thing as a safe height to work at. The truth is working at any height carries a risk and therefore detailed risk assessment is a critical part when planning to work at height.

There can be a further complicating factor in identifying risk and that is that the person may not appreciate that they are working at height. I can recall several investigations where people went to conduct a short task on a roof, they were not near the edge of the roof and did not perceive that they were in any danger. However, as we all know, there can be hidden dangers with fragile rooves. The classic case is the asbestos cement roof, very popular and common on industrial buildings. These roofs were often painted or coated especially as they got older and so it was not always possible to tell that they were asbestos cement. The biggest problem with these roofs is that the material becomes very brittle when exposed to sunlight and the constant cycle of weather. Unfortunately, many workers would step on the roof surface thinking it was strong and weight bearing and then fall through as the brittle material fractured. I also came across other cases where the workers were concerned about the roof but thought it would be okay as long as they walked along the bolt line (which usually had a structural beam underneath), but of course if someone stumbled or strayed off the line, again they would come crashing through.

“working at any height carries a risk and therefore detailed risk assessment is a critical part when planning to work at height”

Questions of Safety

Clearly there are many things to consider when planning to work at height; at what height will you be working; how long is the job likely to last (expected duration), will you need to handle materials while you are at height, will you need to use hand tools or power tools; how many people will work at height, just you or colleagues?

These questions form the basis of the information that you need to develop your risk assessment. There are a multitude of different solutions to working at height; ladder, step ladder, scaffold, tower scaffold, cherry picker, elevated mobile working platform, scissors lift, work basket (forklift or crane supported). Then of course there are scenarios where you don’t need a platform, but you might need PPE to keep you from falling; harnesses, lifelines, reel belts, running lines. In recent years, there has also been an increase in the use of abseiling to safely work at height. All of these solutions have merit, the key though is to select the most effective solution for the work at hand.

You may find that the decision has been made for you, as your first consideration must always be what does the local national and/or regional legislation demand that I do? Some countries have very prescriptive legislation that tells you exactly which solution you must use. But this is less and less common these days with most countries adopting a risk-based approach and it is this approach that we will now focus on.

Let’s go back to our questions and see how they influence our decision making. First we consider at what height are we going to be working, or looking at it the other way, how far might we fall? We will consider that the higher we are the greater the risk of serious injury, and therefore the increase in protection we may need.

Safety, illustrated

Let’s take a simple example to illustrate this, suppose we have to change one light bulb, we would be approximately 75cm above the ground. You might decide to use a stepladder or you could use a simple tower scaffold platform. Potentially it might be quicker and easier to use the stepladder, so what other factors might influence your decision? One might be duration, if you only need to replace one single bulb and the job is only going to take 1 or 2 minutes, then the stepladder is a perfectly satisfactory solution. However, if you have hundreds of bulbs to replace and some of the bulbs are fluorescent tubes then the stepladder probably would not be so good and then the small tower scaffold (work platform) would be much more effective.

If you had one bulb to replace but it was 5m above the ground, then a ladder solution would likely not work and at that height a work platform; be it a tower scaffold, cherry picker or MEWP would be much more effective.

So the height at which you are working and the duration of the job are key considerations, but you also need to consider what you are going to do when you get there. If the job details using a small hand tool like a screwdriver and it is a short duration job, and less than 2 metres above the ground, then a ladder solution may be considered satisfactory. There are no definitive rules about what types of hand tools can be safely used of a ladder, but suffice to say that the heavier the tools (hammer, saw, etc) then the more significant the risk and the likelihood that you would have to consider a platform solution instead. If you have to use both hands for the task that would negate the use of a ladder. So if you need a hammer and chisel or if you need to hold an item in one hand and saw it with the other that would be a task for a safe work platform and not a ladder. As soon as you start to use power tools, you should use a work platform and not a ladder.