Science & Technology

Particulate Matter (PM) Air Quality Standards - Documents from Review Completed in 2006

Emissions Inventory System - FAQ

Emissions Inventory System FAQs

Industrial Sources - FAQ

NEI Industrial Sources FAQ

What does "NEC" stand for in the emissions sectors?

NEC means “not elsewhere classified” and includes SCCs that are not assigned to any of the other specific industrial process sectors. If you look at the SCC code table available at the SCC web site and filter on the Sector name that includes “NEC”, you can see the type of…

Last published: February 26, 2025

CBRN Consequence Management Advisory Team

The Chemical, Biological, Radiological, and Nuclear CMAD provides scientific support and technical expertise for decontamination of buildings, building contents, public infrastructure, agriculture, and associated environmental media.

Volume 3b - Area Source Method Abstracts

Nonpoint (area) source emission reference materials from the Emissions Inventory Improvement Program (EIIP). Provides brief summaries of nonpoint methods for seven categories.

Climate Change Indicators: Cold-Related Deaths

This indicator presents data on deaths classified as “cold-related” in the United States.

Climate Change Indicators: Heat-Related Deaths

This indicator presents data on deaths classified as “heat-related” in the United States.

Poster Sessions of 2017 International Emissions Inventory Conference

Poster presented at the 2017 Emission Inventory conference.

Volume 10 - Emissions Projections, Final Report

Projected future emissions estimation methods from the Emissions Inventory Improvement Program (EIIP).

Where can I find older NEI data (prior to 2008)?

The raw data and summaries that are still available (dating back to 1990) can be obtained from the web page https://www.epa.gov/air-emissions-inventories/pollutant-emissions-summary-files-earlier-neis . Starting with 2001 data, a more limited selection of summary files are available.

Last published: February 26, 2025

What is included in the emissions “Tiers”?

The Tiers are assigned by a Source Classification Code (SCC), which has the most detail about the emissions processes that generate the emissions. The full list of SCCs, their associated Tiers, and the SCC descriptions is available online at https://sor-scc-api.epa.gov/sccwebservices/sccsearch/ .

Last published: February 26, 2025

Particulate Matter (PM) Air Quality Standards - Documents from Review Completed in 2012

Where are the NAICS/ SIC and SCC codes changes that have been implemented for the 2017NEI?

Please refer to the NEI webpage for 2017 documentation , and follow the link for Appendix 2 - 2017 NEI Plan Code Changes. That Excel file describes anticipated changes for the SCCs and NAICS and includes a helpful read me. I'll just note in the next NEI/EIS email that SCC…

Last published: February 26, 2025

The FTP download is not working; what do I do?

Option 1:  The FTP site is active, but some browsers are no longer supporting the ftp:// protocol.  You can access the same data by replacing “ ftp://newftp.epa.gov / ” with  “ https://gaftp.epa.gov/ ” and keep the rest of the URL the same.  The filenames you see will be shorter, but…

Last published: February 26, 2025

What is the definition of VOC?

There is a regulatory definition of VOC. It is found in 40 CFR 51.100. CFR - code of federal regulations. The definition relates to the intent and requirements of the Clean Air Act. Excerpt from “Volatile Organic Compounds” Definition per 40 CFR Part 51.100(s): " Volatile organic compounds (VOC) means…

Last published: February 26, 2025