Risk Management Plan Data Elements

4. Flammables: Worst Case

Complete once for each Program 1 process, and once to cover all flammables held above the threshold quantity in Program 2 or Program 3 processes. See the RMP Offsite Consequence Analysis (OCA) Guidance for more information on determining your worst-case release scenarios.

4.1 Chemical: The name of the regulated chemical evaluated in the worst-case scenario.

4.2 Results based on (check one): Indicate with a check mark whether you used the reference tables provided in the OCA guidance or conducted modelling to calculate your worst-case release. If you performed modelling, you must also indicate which model was used.

4.3 Scenario (check one): Indicate with a check mark which of the following release scenarios is appropriate to describe your worst-case release scenario. Generally the worst-case release scenario is a vapor cloud explosion.

1. Vapor Cloud Explosion: An explosion of a cloud made of a mixture of a flammable vapor or gas with air.

2. Fireball: The atmospheric burning of a fuel-air cloud in which the energy is mostly emitted in the form of radiant heat. As buoyancy forces of the hot gases begin to dominate, the burning cloud rises and becomes spherical in shape. Often caused by the ignition of a vapor cloud of a flammable substance.

4.4 Quantity released: Indicate the quantity of the chemical released during the worst-case release in pounds.

4.5 Endpoint used: For vapor cloud explosions, the endpoint is 1 PSI overpressure; for a fireball the endpoint is 5 kw/m² for 40 seconds.

4.6 Distance to endpoint: Indicate the distance in miles to the endpoint for the chemical specified.

4.7 Residential population within distance: Indicate the population within the distance to the endpoint as specified in question 6 of this section. Populations should be estimated within a circle with a center at the point of the release and a radius determined by the distance to the endpoint. Populations estimated need only include residential populations and may be rounded to two significant digits (e.g., 5,500, 11,000).

4.8 Public receptors: These are the public receptors within the distance to the endpoint specified in the worst-case release. Check all that apply. See question 2.13 of this guidance.

4.9 Environmental receptors within distance: Environmental receptors should be identified within a circle with a center at the point of the release and a radius determined by the distance to the endpoint. Check all that apply. See question 2.14 of this guidance.

4.10 Passive mitigation considered: Mitigation means specific activities, technologies, or equipment designed or deployed to capture or control substances upon loss of containment to minimize exposure of the public or the environment. Passive mitigation means equipment, devices, or technologies that function without human, mechanical, or other energy input. Check all that were considered in defining the release quantity or rate to the worst-case scenario.

1. Dikes: A low wall that acts as a barrier to prevent a spill from spreading.

2. Fire Walls: A wall constructed to prevent the spread of fire.

3. Blast Walls: A heavy wall used to isolate buildings or areas that contain highly combustible or explosive materials.

4. Enclosures: Physical containment of the release within a structure (e.g., a building).

5. Other (specify)

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