Robb Tinney, Safety Advisor
Safety Management Group
OSHA reports that nearly two out of three construction workers frequently perform at least part of their work on scaffolding. Although they may not think of scaffolds as dangerous places, roughly 4,500 workers are injured each year in scaffold-related incidents, and as many as 50 actually die.
Are scaffolds inherently dangerous? As with so many other aspects of safety, being aware of the hazards and following proper procedures to minimize risks will eliminate much of the potential for problems and injuries.
While there are many different kinds of scaffolding, the most common on construction sites and in manufacturing applications is the fabricated modular frame type that can be assembled quickly, offering versatility for a variety of heights and tasks. We’ll focus on frame scaffolds in this article, although much of the information also applies to other types.
1. Start with training
The safe use of scaffolds demands that they be erected, moved, dismantled, and maintained properly, and that all workers who perform tasks on the scaffold fully understand the correct safety procedures. Both needs are best addressed through mandatory training. The former is normally referred to as Competent Person training. Under safety regulations, a competent person is responsible for overseeing and coordinating scaffolding.
The training for workers who actually use the scaffolding should focus on correct use of the scaffold and how to handle materials and tools when working on it. They should be made aware of load ratings and how that may affect their tasks, as well as needed fall-protection equipment and other hazards such as electrical wires.
Training should be updated whenever substantial changes are made to the scaffold’s structure or the tasks that are being performed.
2. Follow the instructions
Some incidents involving scaffolds can be avoided by remembering a very basic piece of advice: follow the instructions. Workers can become so familiar with scaffolds that they make the mistake of assuming that all systems and applications are exactly the same. That’s not the case.
For example, I’ve seen workers interchange components from different manufacturers when they can’t find the piece they need. Scaffolds may be fairly simple structures, but each system is engineered differently. Using a component from another manufacturer or system may mean that the scaffold doesn’t have its full structural integrity. If you’re fortunate, it may only be a little unstable, but in the worst case, it could collapse. Unless the manufacturer specifically indicates that the components are compatible and can work together, don’t mix them.
The rule of thumb for scaffolds is that they will become unstable once the overall height is four times the length of the shortest part of the base – and that only applies when the scaffold is properly assembled, has been set on the correct base, and is plumb. Going beyond that limit – even for a comparatively brief task – is inviting trouble. Don’t forget that extreme weather conditions may rule out the use of an otherwise safe scaffold.
Scaffolds should always be set on a firm foundation. Mud sills or base plates may be needed, depending upon the condition of the surface. If you use an uneven or stable surface, or a mobile piece of equipment that hasn’t been designed specifically as a support, the scaffold will be inherently unsafe. All bracing must be properly installed and secured so it cannot become loose.
Most of all, scaffolds should be erected or modified only with the direction and supervision of a competent person – and any scaffolds that are more than 125 feet in height above the base must be designed by a registered professional engineer, reflecting the additional hazards and structural stress involved with such heights.
3. Consider the hazards
The hazards associated with the use of scaffolding vary with the nature of the tasks being performed and the operating environment. Generally, the biggest hazard is falls, which is why guardrails or some type of fall-protection equipment are required on scaffolds that are at least ten feet above the ground or next level.
Most scaffolds are constructed from metal components, so their proximity to live power lines may create an electrocution hazard, especially when workers are using metal strapping or tools. Overhead lines and equipment may also pose a hazard for head injuries.
Weather conditions can create hazards on scaffolds that are used outdoors or that may be exposed to the elements (such as in partially finished buildings). If the platform becomes wet or icy, it creates a risk for skips and falls. Or, if icicles form on portions of the structure above the scaffold, they may thaw and suddenly drop on workers.
One potentially hazardous area that workers may not always consider is their access to and from the scaffold. The potential for slips and falls is greatest when they’re climbing on or off the scaffold. Because OSHA regulations prohibit using a scaffold’s bracing as a point of access, the competent person on the site must ensure that safe access is available, and is used properly. If hook-on or attachable ladders are the access method, they must be designed specifically for the scaffold and positioned so that they do not cause the scaffold to tip. Stair-style ladders must provide handrails, rest platforms, and treads that minimize the chance of slipping.
4. Use a tagging system
The competent person on a site is also responsible for providing instructions to workers as to whether the scaffold is safe to use. The most common method involves attaching one of three color-coded tags to the scaffold.
A green tag signifies that the scaffold has been inspected and is safe for the intended use, while a red tag sends a warning that it is not safe for occupancy, either because it’s being erected, or because there’s a problem with the scaffolding or the environment.
Finally, a yellow tag informs workers that the scaffolding is safe to use under certain conditions. An example would be a yellow tag that reminds workers that they can occupy the scaffold if they are using adequate fall protection. Another example would be a warning about specific trip hazards on the particular section of the scaffold.
5. Inspect and re-inspect
One of the competent person’s most important responsibilities is to inspect the scaffolding at least every day, and more often when necessary (such as during changing weather conditions). The inspection should consider the activities that will be performed on the scaffold that day, verifying that the scaffold will provide a safe place from which to work. It should include the work platform itself, as well as the integrity of the entire structure.
In a work environment that involves multiple shifts, such as a manufacturing plant or petrochemical refinery, a competent person should be available for each shift, and should conduct his or her own inspection for the benefit of the workers on that shift. If a yellow or red tag from the previous shift is noticed, the competent person should pay particular attention to the reason for the tag to determine if it is still needed.
One more: respect their complexity
Scaffolds may seem to be fairly simple structures, but they actually involve complex engineering and the optimal interaction of a variety of different forces. That’s why the companies that design and build them invest so heavily in engineering – and why it’s so important to ensure that the people entrusted to oversee them on jobsites receive adequate training.
Having respect for the complexity of scaffolds and ensuring that all employees involved with their erection and use are properly supervised, will have a dramatic impact on reducing the number of injuries and equipment damage caused by scaffolding mishaps. That means a small investment in extra attention can have a significant payoff.