Sometimes on jobs, we find makeshift caps, such as mushroom caps, soda or water bottles or tin cans, being used as impalement protection. This is false security. Mushroom caps are only meant as protection for horizontal rebar, to prevent scratches. The others are not strong enough to withstand the force of a falling person. A rebar cap works by spreading out the force of you falling on a greater surface area.
Very often workers will remove caps to set forms, or finish concrete, saying that they will replace them when they are done, or at the end of the day. This protects the people who come after them, but not these workers. We need to replace caps immediately. As soon as stakes are in the ground, even if just for a few minutes to take level measurements, they need to be capped.
Using rebar caps won’t prevent injury entirely. If you fall on a cap, you are likely to break ribs or have severe bruising. This is still preferable to being impaled through the chest or leg. If a worker is impaled, and the object is removed too soon, the worker could bleed to death before help arrives. Removal of the object can take a lot of time and possibly cause more injury. The object may need to be cut off, causing vibration and heat to the injured worker.
So at what vertical height do you no longer need caps? What if the rebar is only sticking up 4 inches, or 4 feet? OSHA doesn’t specify the height, but ask yourself, can you be impaled on 4 inches of rebar? As for taller rebar, if anyone on the job could trip and fall, and the rebar could hit them under the chin or in the neck, it should be protected. Anything under 6 feet tall is a good rule of thumb. Also, if workers are overhead, above rebar, such as above a trench, then all vertical rebar needs protection. The only exception is if the worker is prevented from falling and reaching the rebar by guardrails or other systems.
Use only the larger square, large round or wagon wheel style caps. Broken or defective caps must be removed from the jobsite. Once the corners start breaking off, get rid of them. If you see a cap on the ground, help out and put it back on. Do not put two rebar into one cap, and do not use the yellow caps unless there is lumber in them. Let your supervisor know if you need caps, don’t do the work without them. Temporary fence posts should also be protected, unless taller than the workers. A person falling off a truck bed onto a fence post faces the same danger as someone on the ground.