A hard hat is a protective helmet approved for use in a workplace to protect the head from injury by falling objects, impact with other objects, debris, bad weather and electric shock.
A hard hat is equipped with internal webbing that spreads the weight of the helmet (and therefore the shock of impact) evenly over the entire area of the helmet and top of the head. The internal harness also provides a 30 mm "buffer zone" between the shell and the head that will reduce the likelihood of impact from a falling object being transferred to the skull.
Features of hard hats can include a choice of shapes, ventilation, colours, adjustments and accessories.