8.2 Working at Height

What affects the risk from working at height

The basic hazards of working at height are as follows.

• Vertical distance. This is the main factor in the risk. Generally, the greater the distance, the greater the risk. Falls from any height can cause injury, though, and a fall from as little as 2 metres can be fatal.
• Fragile roofs. A fragile roof surface cannot support the weight of a person. These are likely to be fragile:
  • old roof lights
  • old liner panels on built-up sheeted roofs
  • non-reinforced fibre cement sheets
  • corroded metal sheets
  • glass, including wired glass
  • rotted chipboard
  • slates and tiles
• Deterioration of materials. The structure that people work on should be sound, but materials deteriorate over time when exposed to the weather or attacked by insects. Unsound materials are a hazard in two ways: the material may break when someone puts weight on it, causing a fall through the surface, and the material may break off and fall onto people below. It may not be obvious that deterioration has occurred until it is too late, so care must be taken to make sure that materials are sound and secure.
• Unprotected edges. Where the edges of a surface people work on are open, the risk of falls and falling objects rises greatly. This applies to roofs, elevated walkways, scaffolding, access platforms and so on.
• Unstable or poorly maintained access equipment. Access equipment that is wrongly sited, poorly built or poorly secured is inherently unstable, and overloading, high winds or overreaching can then cause a catastrophic collapse. Whatever equipment is chosen for work at height must be assembled and installed according to the manufacturer's instructions and inspected regularly for signs of deterioration. Where safety depends on how the equipment is installed or assembled, as with scaffolding, it should be inspected in place before it is used. Where equipment is exposed to conditions that could cause dangerous deterioration, such as high winds, it should be inspected at suitable intervals and each time exceptional circumstances arise that could affect its safety.
• Weather. Weather is the most uncontrollable workplace condition. Rain and freezing temperatures make slipping and falling more likely, and strong winds can dislodge materials, equipment or even workers. Workers cannot control these hazards, but they must adapt to changing weather to avoid accidents.
• Falling materials. Objects falling from height can do considerable damage to people and to whatever they hit. They may be loose structural material, waste material, or dropped equipment and tools. Regular safety checks reduce the likelihood and make the workplace safer.

Summary notes for Element 8 · Cheat sheet · Glossary. A study aid, not published or endorsed by NEBOSH.