For each toxic substance, one alternative scenario must be submitted. For example, if a facility has 5 toxic substances, the Offsite Consequence Analysis must have one worst-case analysis and five alternative scenarios.
For each flammable substance, one alternative scenario must be submitted to represent all flammables. For example, if a facility has 6 flammable substances, the Offsite Consequence Analysis must have one worst-case analysis and one alternative scenario for the worst-case flammable substance.
For the alternative scenario(s), the facility must create a scenario which is more applicable to the facility.
Consider a release scenario that is more representative of your facility, such as transfer hose releases, process piping releases, vessel or pump releases due to cracks, spills, and shipping mishaps. Consider a 5-year accident history as a basis for the alternative scenario(s).
Active, passive, and administrative controls can be used for the alternative scenario(s).