A TERA — Toxic Exposure Risk Activity — is VA's finding that your service involved exposure to toxic substances. It is not a presumptive condition. It's the path that matters when your condition isn't on a presumptive list: a documented TERA triggers VA's duty under the PACT Act (§303, codified at 38 U.S.C. 1168) to get a medical nexus opinion tying your condition to the exposure. Presumptive eligibility is automatic; a TERA is what earns you the exam when it isn't.
Straight talk first
Most toxic-exposure guides stop at presumptives — the lists where VA assumes the link. But what if your condition isn't on a list? Before the PACT Act, that often meant you were stuck proving causation alone. TERA is the fix for that gap. If VA determines your service involved a toxic-exposure activity and you have a current diagnosis, the law now requires VA to order an exam and get an opinion on whether your condition is "at least as likely as not" connected. That's a real, under-used door — and most veterans have never heard the word.
This is the non-presumptive cut of the framework on VA presumptive conditions.
What a TERA actually is
VA defines a toxic exposure risk activity as participating — at home or abroad — in an activity that may have exposed you to toxins. VA's categories include:
- Air pollutants — burn pits, sand, dust, particulates, oil-well fires, sulfur fires.
- Chemicals — pesticides, herbicides, depleted uranium (embedded shrapnel), contaminated water.
- Occupational hazards — asbestos, industrial solvents, lead, certain paints (including chemical agent resistant coating), firefighting foams.
- Radiation — nuclear weapons handling and detonation, radioactive material, calibration sources, X-rays.
- Warfare agents — nerve agents, chemical and biological weapons.
The list isn't exhaustive and there's no fixed timeframe.
TERA vs. presumptive — the distinction that matters
| Presumptive | TERA | |
|---|---|---|
| The link | VA assumes it | VA orders an exam + opinion |
| Your condition | Must be on a list | Can be off-list |
| Exposure | Presumed for covered service | Determined from your record |
| What you still need | Diagnosis + covered service + filed claim | Diagnosis + TERA finding + filed claim |
If your condition is presumptive, use that — it's faster. The PACT Act guide, burn pits, and Agent Orange cover the listed paths. TERA is for everything outside those lists.
How VA decides you had a TERA
You don't file for it separately. VA makes the determination from the record when you file a claim or enroll in VA health care. It can be established:
- Explicitly — service records, or an exposure VA already conceded in a prior claim.
- Implicitly — service in a location presumed associated with toxic exposure, a military occupational specialty (MOS) tied to exposure, or medical records / a VA exposure screening suggesting it.
Because so much rides on the record, this is where pulling your service and exposure records early pays off.
What a positive TERA triggers (38 U.S.C. 1168)
Under Section 303 of the PACT Act, if you submit a claim with evidence of a disability and evidence of TERA participation, and that's not already enough to grant service connection, VA shall provide a medical examination and obtain an opinion on whether it's at least as likely as not that there's a nexus to the exposure. The provider must weigh exposure across all your deployments and the combined effect of multiple activities. The only carve-out is when VA finds no indication of any association at all.
A strong, independent nexus letter can complement — not replace — that VA opinion. And once a condition is granted, see how it moves your total in the VA Combined Rating Calculator.
The health-care side
Separate from compensation, the PACT Act made toxic-exposed veterans eligible for VA health care and directed VA to offer toxic-exposure screening. Getting screened both gets you care and can put exposure evidence into your record — which is exactly what a future TERA determination draws on.
Key takeaways
- A TERA is VA's finding that your service involved toxic exposure — not a presumptive.
- It's the path for conditions off the presumptive lists: a TERA triggers VA's duty to get a nexus medical opinion (PACT Act §303 / 38 U.S.C. 1168).
- You don't apply separately — VA determines it from your records, MOS, presumed locations, or exposure screening.
- The opinion standard is "at least as likely as not," and VA must weigh all exposures together.
Frequently asked questions
- What is a TERA (Toxic Exposure Risk Activity)?
- A TERA is VA's determination that, during service, you took part in an activity — at home or abroad — that may have exposed you to toxic substances such as burn-pit smoke, airborne particulates, herbicides, contaminated water, radiation, asbestos, solvents, or warfare agents. VA records it as a yes/no finding tied to your service, not a separate benefit.
- Is a TERA the same as a presumptive condition?
- No. A presumptive means VA assumes the link for a listed condition and covered service, so you skip proving exposure and nexus. A TERA is the path when your condition is NOT presumptive: a documented TERA triggers VA's duty to obtain a medical nexus opinion connecting your condition to the exposure. Presumptive is automatic; TERA earns you the medical exam.
- Do I apply for a TERA determination separately?
- No — you don't file a separate TERA application. VA makes the TERA determination using your records when you file a disability claim or enroll in VA health care. It can be established explicitly (records or a conceded prior exposure) or implicitly (service in a presumed-exposure location, a qualifying military occupational specialty, or a VA exposure screening).
- What happens if VA finds I participated in a TERA?
- Under Section 303 of the PACT Act (38 U.S.C. 1168), if you submit a claim with evidence of a current disability and evidence of TERA participation, and that evidence isn't already enough to grant the claim, VA must provide a medical examination and obtain an opinion on whether it is at least as likely as not that your condition is linked to the exposure. The exception is when VA finds no indication of any association.
- What kinds of service count as a TERA?
- VA's categories include air pollutants (burn pits, sand, dust, oil-well and sulfur fires), chemicals (pesticides, herbicides, depleted uranium, contaminated water), occupational hazards (asbestos, industrial solvents, lead, certain paints, firefighting foams), radiation, and warfare agents. The list isn't exhaustive and there's no fixed time period — VA weighs all available evidence.
Sources
- VA — The PACT Act and your VA benefits: https://www.va.gov/resources/the-pact-act-and-your-va-benefits/
- 38 U.S.C. 1168 — Medical nexus examinations for toxic exposure risk activities: https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title38-section1168&num=0&edition=prelim
- Federal Register (Oct 1, 2024) — VA adjudication regulations for claims based on toxic exposure: https://www.federalregister.gov/documents/2024/10/01/2024-21852/va-adjudication-regulations-for-disability-or-death-benefit-claims-based-on-toxic-exposure
- VA — Hazardous materials exposure (presumptive conditions hub): https://www.va.gov/disability/eligibility/hazardous-materials-exposure/
