How safe are plastic mushroom caps?

“The purpose of this alert is to advise employers and employees of the dangers of falling against exposed reinforcement bars, even if they have plastic protective covers (known as rebar-caps) attached.  It also provides advice to suppliers of rebar-caps.


An incident occurred in New South Wales in which a person stumbled and fell, impaling himself on an exposed reinforcement bar. The bar had a rebar-cap on it, but the cap offered no protection against impalement as the weight of the worker against the rebar-cap was sufficient for it to be pierced by the bar.

Research carried out following the incident included tests that involved dropping a 20kg bag of sand one meter onto a vertical reinforcement bar. This showed that standard rebar-caps provide little, if any, protection against impalement on reinforcement bars should a person fall against them, even for a fall on the same level.

Any protection offered by the rebar-caps, no matter how slight, was greatly reduced if they were the wrong size for the bar or were incorrectly fitted. These findings were supported by information obtained from a number of suppliers who stated that the rebar-caps are only intended to provide visual warning of a hazard and protection against brush contact with burred ends of the bars.

They are NOT a means to control the risk of impalement.”

Source: Extract Safety Bulletin: