National Tier II Data Standard

The Emergency Planning and Community Right-to-Know Act (EPCRAexternal link) requires sites that have specific hazardous chemicals above certain amounts to complete an annual Tier II form. These forms include information about the chemicals on site (such as types, quantities, and locations), as well as other important details like contact information for their site’s owner/operator. Throughout the United States, the Tier II data is collected and stored in a variety of programs.

A national Tier II data standard has been created to establish a common set of guidelines (or rules) for reading, writing, and sharing Tier II data between different Tier II management systems. The data standard was developed by NOAA and the Environmental Protection Agency (EPA), with collaboration from Tier II stakeholders throughout the country. Version 1.0.0 of the national Tier II data standard was published as a Document Type Definition (DTD) schema on October 11, 2016.

The national data standard was proposed in response to Executive Order 13650external link (Improving Chemical Facility Safety and Security), which calls for improving operational coordination between federal, state, local, and tribal organizations; enhancing information collection and sharing; and modernizing regulations, policy, and standards.

Data Standard Support Files

We offer these files to help you work with the data standard:

  • DTD (Document Type Definition) [DTD, 12 KB]: This file defines the way data must be structured in the XML files to adhere to the Tier II data standard. Important comments are included in the file to help guide users who are adopting the standard. If you’re new to DTD, see this introductory DTD tutorialexternal link.
  • Sample Data File [XML, 14 KB]: A sample data file using the 1.0.0 data standard. This is a sample of how the data standard looks in a submission file generated using the Tier2 Submit™ program. Note that this document does not include important notes found in the DTD file. To gain a complete understanding of the data standard, please view both files.

File Structure of Tier2 Submit Exports

NOAA and EPA also develop a Tier II management program called Tier2 Submit, which allows chemical sites to complete Tier II forms electronically. Tier2 Submit 2016 and later can import and export Tier II data files that are formatted using the XML-based Tier II data standard.

The new Tier2 Submit export (or submission file) is a zipped file containing several components:

  • An XML file called “epcra_tier2_data.xml.”
  • A "SitePlansTemp" folder (but only if you added attachments, such as site plans or photos, to your data). The SitePlansTemp folder contains one subfolder for each facility that has attachments. The name of each subfolder matches the record ID of its respective facility. For example, the sample data file above contains a facility element with a recordid attribute of “FATR20176YVD7R002I2E”, so the SitePlansTemp folder will contain a corresponding subfolder named FATR20176YVD7R002I2E. This subfolder will contain the attachment files, such as site plans or photos, for this facility.
  • Tier2 Submit 2017 exports also include several MER files. See “Transition Period” below.

The image below shows the structure of a zipped Tier2 Submit submission file that includes one facility with two attachments.

Transition Period

In addition to importing and exporting data using the new XML data standard, the 2017 version will continue to support the previous zipped MER file format in a limited capacity. To support a transition to the new format, Tier2 Submit 2017 export files include MER files in the old format in addition to the new XML file. This will allow other Tier II management programs—which may be programmed to share data in the MER file format—additional time to adopt the new data standard. Tier2 Submit 2017 will import MER files for report years 2015 and (if the submission file contains MER but not XML) 2016 and 2017. Support for the older MER file format will be phased out in future Tier2 Submit versions.

Tier2 Submit files can be imported directly into the CAMEOfm database program for emergency response and planning purposes. CAMEOfm version 3.3 and later accept imports of Tier II data that adhere to the national standard, but it will not include any additional XML import or export support beyond that.


Contact us with questions, comments, or suggestions about the national Tier II data standard.