Guard rails, toe boards and other similar barriers ought to be provided to avoid an individual or any type of product or things falling from a workplace. http://ifi.edu.vn/index.php?language=vi&nv=users&nvvithemever=t&nv_redirect=aHR0cHM6Ly90dXBhbG8uY29tL2VuL3VzZXJzLzY0ODcwMTM