EPA Toxics Release Inventory (TRI)

The Toxics Release Inventory (TRI) is the U.S. EPA’s annual program tracking releases and other waste management of listed toxic chemicals. Facilities above size and chemical-throughput thresholds in covered industry sectors must report under Section 313 of the Emergency Planning and Community Right-to-Know Act (EPCRA). Each record is at the facility x chemical x year level: on-site and off-site releases (to air, water, land), plus recycling, energy recovery, and treatment quantities. Reporting began for 1987. Used in, for example, Duchin, Gao & Xu for plant-chemical-level toxic emissions (total pollution, pollution intensity, abatement), 1,056,361 plant-chemical-year observations, 2000-2020.

• Cost: free, public.
• API key: none required.
• Coverage: facility x chemical x year, reporting years from 1987 to the most recent processed year, for covered industry sectors and listed chemicals.
• Home: https://www.epa.gov/toxics-release-inventory-tri-program

Access

All paths below need no key. The bulk path gives you a full year of national data in one file; the Envirofacts REST service lets you slice individual TRI tables. The TRI Basic Data Files (annual CSV/ZIP) are also published on the EPA website if you prefer to download by hand.

Option 1: bulk CSV (one year, national)

A materialized download view returns a full year of US data as a single CSV:

# (a) Bulk: one year, national, as CSV (no key)
curl -sL -o tri_2022_US.csv \
  "https://data.epa.gov/efservice/downloads/tri/mv_tri_basic_download/2022_US/csv"

The 2022 US file is roughly 25 MB. Load it as strings first, then cast the columns you need:

import pandas as pd

df = pd.read_csv(
    "tri_2022_US.csv",
    dtype=str,           # read everything as str first; cast after schema alignment
    low_memory=False,
)

# Cast key fields after inspecting column names and the unit column
df["total_releases"] = pd.to_numeric(df["TOTAL RELEASES"], errors="coerce")

Inspect the header before casting; column names and the unit column matter (see Gotchas).

Option 2: Envirofacts REST service

The Envirofacts service exposes TRI tables directly. The URL grammar is:

https://data.epa.gov/efservice/<table>/<column>/<value>/rows/<start>:<end>/<format>

<format> can be JSON or CSV. The rows/<start>:<end> window is required for large tables.

# (b) Envirofacts REST: a windowed slice of a TRI table as JSON (no key)
curl -sL "https://data.epa.gov/efservice/tri_facility/state_abbr/CA/rows/0:1/JSON"

This returns facility records with fields such as tri_facility_id, facility_name, street_address, city_name, county_name, state_county_fips_code, state_abbr, zip_code, region, fac_closed_ind, and frs_id. Page through a table with successive windows (rows/0:9999, rows/10000:19999, and so on).

Gotchas (the ones that bite pipelines)

• Self-reported estimates, not measured emissions. TRI quantities are estimates; estimation methods vary by facility, and reported values can be revised and back-filed in later releases. Pin the release year you pulled.
• Chemical list and thresholds change across years. A chemical added in a given year appears to jump from zero. That is a reporting-scope change, not a real increase. Check whether a chemical was reportable in the years you compare.
• Covered sectors have expanded over time. Do not read a sector first appearing in the data as a real onset of pollution; it can be a coverage change.
• Units: pounds, except PBT chemicals in grams. Quantities are in pounds, except certain highly toxic persistent bioaccumulative and toxic (PBT) chemicals (such as dioxin and dioxin-like compounds), which are reported in grams. Never sum the raw quantity column across chemicals without unit-aligning first; do not sum pounds and grams.
• Facility identity drifts. TRI Facility ID, FRS ID, and parent-company name do not map one-to-one, and ownership changes across years break a naive facility panel. This matters for any buyer/seller or plant-tracking analysis (as in the citing paper); link facilities deliberately across years.
• On-site vs. off-site, released vs. managed. Do not conflate on-site versus off-site, or “released” versus “managed as waste”. These are distinct columns with distinct meaning.
• Envirofacts needs the rows window. The REST service requires the rows/<start>:<end> window for large tables, or the request times out. Page through with successive windows.

Citation

Cite the U.S. EPA, the Toxics Release Inventory, the reporting year(s), and the specific file or Envirofacts table used, with the EPA URL and the access date, for example: U.S. Environmental Protection Agency, Toxics Release Inventory (TRI), reporting year 2022, TRI Basic Data Download (mv_tri_basic_download/2022_US), retrieved from https://data.epa.gov/efservice/downloads/tri/mv_tri_basic_download/2022_US/csv, accessed YYYY-MM-DD. Record the reporting year and the table or file so the pull is reproducible.