Stock photography, photos: Construction site safety sign Stock photos of Safety sign at construction site viewed through security fencing Photograph: © Alan Oliver Click for a larger image and more information Keywords associated with this stock photo: build, building, construct, construction, site, works, fence, safety, security, bar, railing, sign, alert, symbol, logo, prevent, prohibit, mandatory, statutory, legal, notice, inform, advise, safe, secure, protect, protection, wear, clothing, hat, head, gear, boots, protective, authorised, unauthorised, authorized, unauthorized, no, admittance, danger, risk, health, health and safety,