Danger areas
22. The operator shall ensure that—
(a)any danger areas in the quarry are clearly marked;
(b)equipment or barriers designed to prevent inadvertent entry by any unauthorised person are installed at any danger area in the quarry in which, because of the nature of the work being carried out there or for any other reason there is—
(i)risk of a person falling a distance likely to cause personal injury;
(ii)risk of a person being struck by a falling object likely to cause personal injury; or
(iii)a significant risk to the health and safety of persons; and
(c)where any person at work is authorised to enter a danger area, appropriate measures are taken to protect his health and safety.