Chapter 18 - Evacuation

Abstract

Evacuation routes are of prime importance for the safety of plant workers during an emergency. Two evacuation routes, which must be located as far apart as possible, should be provided from all hydrocarbon processes or normally occupied work areas. Areas that are considered low hazard may be allowed one escape route. The exception to this is rooms located on an offshore installation in proximity to hydrocarbon processes. Evacuation routes should also be generally straight and direct to points of safety or embarkation. Exit routes and doors from all facilities should be provided according to the requirements of National Fire Protection Agency (NFPA) 101. The minimum width of all exit routes should not be less than a standardized width—1.0 meter (39 inches) being commonly adopted. Where low occupancy rooms are provided in offshore facilities near process areas, a secondary emergency escape hatch is provided as an alternative means of escape in addition to the normal means of egress. The design of stairways of two or more risers is critical for safe evacuation. Stair widths, rise, and run are arranged and balanced for an effective and orderly evacuation. Inattention has been proved to be the single most factor producing the greatest missteps, accidents, or injuries. Life safety codes for the installation of stairs place limitations on the use of winding, circular, and spiral stairways to ensure adequate egress routes are provided for emergency periods.