This new recommended practice provides guidance for reducing the risk to personnel located in portable buildings from potential explosion, fire and toxic release hazards. While occupied permanent buildings (e. g., control rooms, operator shelters) located near covered process areas are typically constructed to be blast and fire resistant, conventional portable buildings (i.e., light wood trailers) are typically not constructed to be blast and fire resistant. Past explosion accidents have demonstrated that occupants of conventional portable buildings are susceptible to injuries from structural failures, building collapse, and building debris and projectiles. Guidance is provided based on the following principles: Locate personnel away from covered process areas consistent with safe and effective operations. Minimize the use of occupied portable buildings in close proximity to covered process areas. Manage the occupancy of portable buildings, especially during periods of increased risk including unit start-up or planned shut-down operations. Design, construct, install, and maintain occupied portable buildings to protect occupants against potential hazards. Manage the use of portable buildings as an integral part of the design, construction, maintenance and operations of a facility.