TERA: what “toxic exposure risk activity” means

What the law says TERA means

38 U.S.C. 1710(e)(4)(C)

The statute says a toxic exposure risk activity is any activity:

• that requires a corresponding entry in an exposure tracking record system for the veteran who carried it out; or
• that the Secretary of VA determines qualifies, taking into account what is reasonably prudent to protect the health of veterans.

In plain words: an activity VA records as an exposure, or one VA decides counts. Section 1120 of the same title uses the term and points back to this definition.

TERA is not a disability and not a list

• Not a disability. VA's page on environmental hazards says you need a “diagnosed illness or other health condition.” The exposure by itself is not paid.
• Not a list. No single “TERA list” of conditions exists. The presumptive lists are separate lists, and they depend on where and when you served.
• Not a claim. Being exposed, or being screened, files nothing.

See Exposure alone is not a disability.

Evidence of a TERA can trigger a medical opinion

38 U.S.C. 1168 — “Medical nexus examinations for toxic exposure risk activities”

The statute says VA must give you a medical exam and obtain a medical opinion when all three are true:

1. You claim a service-connected disability.
2. Your claim has evidence of a disability and evidence you took part in a toxic exposure risk activity during active service.
3. That evidence is not enough on its own to establish service connection.

The opinion has to say whether it is “at least as likely as not” that your disability is linked to the activity, and has to consider your total potential exposure across all deployments.

The exposures VA's own pages list

VA: “Exposure to hazardous chemicals and materials”

• Agent Orange
• Asbestos
• Burn pits and other specific environmental hazards
• Camp Lejeune drinking water — August 1953 through December 1987
• Gulf War illnesses
• Mustard gas or lewisite
• Project 112 or Project SHAD — warfare testing, 1962 to 1974
• Radiation
• Birth defects such as spina bifida, tied to a parent's Vietnam-era service

VA's environmental hazards page also names a sulfur fire at the Mishraq mine near Mosul, hexavalent chromium at the Qarmat Ali water plant in Basra, and a waste incinerator near Atsugi, Japan.

The burn pit and particulate matter list

From VA's presumptive list dated February 4, 2026. Illnesses

• Asthma that was diagnosed after service
• Chronic sinusitis · chronic rhinitis · chronic bronchitis
• COPD · emphysema · pulmonary fibrosis
• Constrictive or obliterative bronchiolitis
• Granulomatous disease · interstitial lung disease · pleuritis · sarcoidosis

Cancers

• Brain, including glioblastoma
• Head of any type · neck of any type
• Respiratory of any type · gastrointestinal of any type
• Reproductive of any type
• Kidney · urinary bladder · ureter · pancreatic
• Lymphoma of any type · melanoma

Blood

• Acute leukemias · chronic leukemias
• Multiple myelomas, including MGUS
• Myelodysplastic syndromes · myelofibrosis

Where and when you served

VA presumes exposure if you served:

• On or after August 2, 1990 in Iraq, Kuwait, Saudi Arabia, the neutral zone between Iraq and Saudi Arabia, Bahrain, Qatar, the United Arab Emirates, Oman, Somalia, the Gulf of Aden, the Gulf of Oman, the Persian Gulf, the Arabian Sea, the Red Sea, or the airspace above them; or
• On or after September 11, 2001 in Afghanistan, Djibouti, Egypt, Jordan, Lebanon, Syria, Uzbekistan, Yemen, or the airspace above them.

You can still claim it

VA says that for a condition that is not presumptive you can still apply, but “you’ll need to submit more evidence to show how your condition connects to your service.” In plain terms, build three things:

1. A current diagnosis of the condition.
2. Evidence of the exposure — where you served, what you did, orders, records, statements from people who were there.
3. A medical nexus — a doctor's opinion that the condition is at least as likely as not linked to the exposure. See the nexus letter.

Statements from people who served with you. VA calls the form a Lay/Witness Statement (VA Form 21-10210); people often call it a “buddy statement.” No form is required, so a signed statement on plain paper also works (see the page linked below). Someone who was there can write about where you were and what they saw. Ask them to include dates, places and what they personally witnessed. See Buddy Statements: who can write one and what makes it work.

Proof worth gathering. Deployment orders, your DD-214, unit records and your medical records. (That list is my suggestion, not a list taken from a VA page.) See what good claim evidence looks like.

File the claim, and get screened

Free help: an accredited VSO representative helps with VA claims at no cost. See who can legally help with your VA claim.

What I could not verify

• Which activities are entered in VA's exposure tracking record system. The statute points to 38 U.S.C. 1119(c) for that term. I did not read it.
• Whether VA's 2024 proposed regulation defining TERA for claims (proposed 38 CFR 3.1) was finalized. I found only the proposal.
• Whether VA has added conditions to the burn pit list since the February 4, 2026 list I read.
• Whether the Gulf War deadline of December 31, 2026 on the presumptive page has changed.
• Refiling rules after an earlier denial. I link to the denial page and do not state them here.
• Statute text was read on Cornell's Legal Information Institute. The official source wins over me.