In March, 2005, an industry event occurred that prompted Sunoco to re-examine our trailer siting procedures. A vapor cloud explosion at another company’s refinery in Texas City, TX during the starting of a raffinate splitter tower killed 15 contract workers and injured 170 other workers. Many of the dead and injured were working in portable trailers located adjacent to the affected process unit. As a result of this catastrophic event, Sunoco commissioned a company-wide review of trailer siting procedures and practices and began development of a corporate standard for siting of portable buildings. The new standard augmented the siting review by adding consequence-based analysis to the frequency consideration of probable events. Toxic release potential also was added to the analysis along with the standard flammable and explosive scenarios. Siting procedures were revised to include pressure contour mapping and a more rigorous approval process requiring signoffs by the facility management team. To provide additional personnel protection, the use of alternative enclosures such as blast resistant trailers and fire retardant tents has been included in the new standard.

The PSM Forum was assigned the responsibility for developing this new standard and guiding it through the approval process.