If a facility stores an Extremely Hazardous Substance (EHS) above the Threshold Planning Quantity (TPQ), they must comply with the emergency planning requirements outlined in Subpart B of EPA's Emergency Planning and Notification regulations. This includes submitting an Emergency Planning Notification to the State Emergency Response Commission (SERC, DEQ in Virginia) and Local Emergency Planning Committee (LEPC). Threshold planning quantities vary with each EHS and can be found in the EPA List of Lists.

While there is no specific format required for Emergency Planning Notifications, the notification must include the following:

• A list of all EHS chemicals stored above their TPQ including their name and CAS Number,
• Contact information for a Facility Emergency Coordinator, and
• Any updates that may be relevant to Emergency Planning requirements (i.e. changes in hazard info for an EHS).

Additional guidance on completing Emergency Planning Notifications and reporting EHS mixtures can be found in Subpart B of EPA's Emergency Planning and Notification regulations.