There is a lot of misconception that a fall from low height is usually low risk. Below is an extract of my explanation of why low height of fall does not automatically lead to low expected severity. This was in the context of a fall from mobile crane.
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“is it so risky that we have to sacrifice all these matters?”
Very good question. This can be a philosophical question! This is at the heart of risk management and the phrase “reasonably practicable”. Wish I can touch on this more, but I hope the following suffice.
Based on the study by Beale et al. (2000) it seems that mortality rate for fall from 10m is significantly higher than those that fell from less than 10m. However, Yusuf et al. (2004) indicates that, “Although there is considerable variability in the injuries produced by falls, a reasonable standard profile of injuries may be constructed from based on the height, contact surface, and body orientation at impact.” Yusuf et al. (2004) went on to state that, “The common belief that falls from a height of less than 10 ft cannot injure is false and can have dangerous consequences since a fall from almost any height can cause serious injury or death.” In addition a trauma surgeon I met in Singapore once said that based on his experience there seems to be no strong correlation between height of fall and severity of the fall.
Like what Yusuf et al. (2004) said, there is considerable variability of the severity of a fall, but the key point is we cannot judge the expected severity of a fall based on height alone. Coming back to our context of mobile cranes. I would say that it is not reasonable to assume that the contact surface for falls from a mobile crane to be soft and cushy. That is because a mobile crane is frequently used in rough environment with rebars sticking out and rocks in the surrounding. It is also not reasonable to assume that the body orientation will be such that the feet lands first, in fact if a guy trip or slip from the bed of a mobile crane, he might very well land on his head (the usual injury location for fatal falls). à As a separate issue, I would advise all employees working at height to put on a chin strap to secure the helmet.
Hence if we are to assess the risk of a fall from 1.2m off the side of a mobile crane (used in a multitude of environment), would you say that the risk is moderate and controls should be put in place as soon as possible, as long as there are reasonably practicable measures to reduce the risk to low risk?
Then the next question is, “is it reasonably practicable to place additional controls?”
If you refer to my earlier post on fall from mobile crane (click here), my take is that those measures are reasonably practicable, but it takes more than my opinion to determine reasonably practicable. Lots of factors need to be considered, e.g. industry norm, codes of practice/standards…
Tags: fall, reasonably practicable, risk, severity