EPCRA Report Types and Terminology


EPCRA requires facilities that store hazardous chemicals above certain thresholds to submit reports to federal, state, and local authorities. This article will help you understand the different EPCRA report types and terminology and how they are commonly referred to by regulators and by us at Encamp.

Initial Report

An initial report notifies authorities of new hazardous chemicals onsite that exceed reporting thresholds. There are two main types:

  • Section 302 Report: Required for Extremely Hazardous Substances (EHS) when quantities exceed the substance's Threshold Planning Quantity (TPQ). This emergency planning notification helps prepare responders for a potential release.

  • Section 311 Report: Required for EHS chemicals above the TPQ as well as other hazardous chemicals above state-established reporting thresholds. Provides information for emergency planning and community right-to-know.

Initial reports are also required when bringing hazardous chemicals onsite at a new facility. In this case, all chemicals are considered new even if reported at other sites.

Update Report

An update report modifies information on a facility's current year Tier II inventory report. For example:

  • Changing inventory quantities that alter range codes

  • Adding or updating storage locations

  • Updating facility owner, contact, or site map information

  • Notifying that site is now below reporting thresholds or is closing

Updates provide the latest information to ensure effective emergency response. They do not add new chemicals like initial reports do.

Some states may consider everything in the Initial Report category to be Update Reports.

Revision Report

A revision report corrects or adds information to a Tier II inventory report from a previous year. For example:

  • A chemical that exceeded thresholds in 2022 but was omitted from the 2022 report would require a 2022 revision report.

  • If new information shows 2022 quantities were actually higher, a revision would update the quantities.

Revisions only apply to past reports, unlike updates which modify the current year. This ensures past records are accurate.

Annual Report

The annual Tier II inventory report provides a facility's comprehensive hazardous chemical inventory as of the past calendar year. It is due on March 1st each year. The annual report includes:

  • Hazardous chemicals onsite above thresholds as of December 31 of the prior year

  • Locations and quantities of those chemicals

  • Storage types and conditions

  • Facility contacts and emergency information

Annual reports provide emergency responders the most up-to-date information on potential chemical hazards at a facility.


  • A new chemical exceeds thresholds onsite in December 2022 but was not included on the RY2022 Annual Tier II report.

    • File a revision report to the 2022 annual Tier II report. Also file an initial report depending on the situation.

  • A new chemical exceeds thresholds onsite in January 2023

    • File an initial Section 302 and/or 311 report. Include this chemical on your RY2023 Annual Tier II report.

  • A chemical previously reported on the RY2022 Annual Tier II Report is now stored in larger quantities in 2023.

    • File an update report to modify quantities.