Do I need a TCEQ air permit?
Almost any new build or change that puts emissions into the air needs TCEQ's sign-off first. This chapter helps you figure out whether your project needs an authorization at all — and if so, roughly which one.
If you're constructing or modifying a facility that emits air contaminants, you need authorization from TCEQ before you build. The one exception is a source small enough to qualify as de minimis. Everything above that line needs something — the only question is which authorization, and that depends on what and how much you emit.
Two questions decide it.
TCEQ's requirement turns on two things. First, are you doing something that triggers review? That means constructing a new facility, modifying an existing one, changing the representations in an existing authorization, or renewing one. Second, does the facility emit air contaminants? If both are true, you need an authorization before the work begins.
"Facility" is broader than people expect. It isn't just a smokestack at a plant — it can be a boiler, a generator, a coating line, a crusher, a storage tank, or a piece of process equipment. And "before you build" is literal: the authorization is a preconstructionrequirement, not something to sort out once you're running.
Before you assume a site is unpermitted, it's worth checking. You can look up any TCEQ air permit's status by company, county, or permit number to see what's already on file.
Which authorization does your project need?
Work down these questions in order. The first one you can answer "yes" to is roughly where your project lands. (This is a map, not a determination — emissions math decides the real answer.)
Do all of your site's emissions meet the de minimis criteria?
Are emissions under the PBR thresholds, and does the source fit one of the 108 permits by rule?
Is your facility a type covered by a standard permit (batch plant, crusher, asphalt plant, boiler…)?
Everything else: a case-by-case review.
A source can move down this ladder by reducing emissions enough to qualify for a lighter authorization. The full landscape — including flexible and major-source permits — is mapped in the Permitting 101 overview, and each type is broken out in Permit types explained.
When you need no permit at all.
De minimis sources emit so little that TCEQ requires no registration or authorization before construction. There are four ways to get there under 30 TAC §116.119(a).
- The De Minimis Facilities List— if your source is a listed facility type, it's de minimis by default [§116.119(a)(1)].
- The material-usage limits — if your total site-wide use of certain materials stays under set yearly caps, you qualify [§116.119(a)(2)]. Proven with purchase records.
- The Effects Screening Level (ESL) caps — if your site stays under the emission-rate caps for indoor sources, you qualify [§116.119(a)(3)]. Proven with calculations.
- A case-by-case review— if you don't fit the first three but still emit very little, you can ask TCEQ to review it [§116.119(a)(4)].
Two rules matter most here. First, there's no partial permitting: every emission at the site, across all facilities, has to fit under de minimis — you can't de-minimis part of a site and permit the rest. Second, de minimis isn't "do nothing": you still have to keep records proving you qualify, you can't be in violation of any TCEQ rule, and other state or federal requirements may still apply.
| Material (site-wide, per year) | De minimis limit |
|---|---|
| Cleaning & stripping solvents | 50 gal |
| Coatings (excluding plating materials) | 100 gal |
| Dyes | 1,000 lb |
| Bleaches | 1,000 gal |
| Fragrances (excluding odorants) | 250 gal |
| Water-based surfactants & detergents | 2,500 gal |
A sample of the material-usage pathway [§116.119(a)(2)]. The full list and the ESL emission-rate caps live in the TCEQ rule; these figures are illustrative, not the complete set.
The permit-by-rule thresholds.
Above de minimis, a source may qualify for a Permit by Rule — a standardized authorization — if its emissions stay under all of these limits and it meets the conditions of one of the 108 individual PBRs.
| Pollutant | Must emit less than |
|---|---|
| Carbon monoxide (CO) or nitrogen oxides (NOx) | 250 tpy |
| VOC, sulfur dioxide (SO₂), or inhalable particulate matter | 25 tpy |
| Particulate matter ≤ 10 microns (PM₁₀) | 15 tpy |
| Particulate matter ≤ 2.5 microns (PM₂.₅) | 10 tpy |
| Any other air contaminant * | 25 tpy |
tpy = tons per year. * Excludes carbon dioxide, water, nitrogen, ethane, hydrogen, oxygen, and greenhouse gases, unless a specific PBR provides otherwise. Meeting the thresholds isn't enough on its own — the source still has to satisfy every condition of an applicable PBR in 30 TAC Chapter 106, and some PBRs require registration while others don't.
Quantify before you classify. Where a project lands depends entirely on its potentialemissions, calculated correctly. This chapter helps you understand the structure — it doesn't replace an emissions calculation or a conversation with TCEQ's Air Permits Division, and TCEQ's Small Business & Local Government Assistance Section offers free help.
Do I need a permit, answered.
Do I need an air permit in Texas?+−
If you plan to construct a new facility or modify an existing one that emits air contaminants, you generally need authorization from TCEQ before construction begins. The exception is a source whose site-wide emissions meet the de minimis criteria in 30 TAC §116.119(a) — those need no registration or permit, though records must still be kept.
What is the de minimis rule for air emissions?+−
De minimis sources emit so little that no authorization is required before construction. There are four ways to qualify under §116.119(a): being on the De Minimis Facilities List, staying under the material-usage limits, meeting the Effects Screening Level emission-rate caps, or requesting a case-by-case review. All emissions at the site must qualify — there's no partial permitting — and you must keep records proving it.
How do I know if I qualify for a permit by rule?+−
A source may qualify if it emits less than 250 tpy of CO or NOx; 25 tpy of VOC, SO₂, or inhalable PM; 15 tpy of PM₁₀; 10 tpy of PM₂.₅; or 25 tpy of most other contaminants — and it meets every condition of one of the 108 individual PBRs in 30 TAC Chapter 106. Some PBRs require registration; others don't.
Does a small business need a TCEQ air permit?+−
It depends on what the business emits. Many small operations qualify as de minimis or fit a permit by rule. TCEQ's Small Business and Local Government Assistance Section offers free, confidential help determining which authorization applies. Even a de minimis site must keep records and may still be subject to other state and federal requirements.
Do I need a new authorization to modify an existing facility?+−
Often yes. Modifying an existing facility that emits air contaminants generally requires authorization before the change is made, just like new construction. Changes to the representations in an existing authorization and renewals of existing authorizations also fall under New Source Review.
Found your level? Now watch the filings.
Whether your project is a permit by rule or a full NSR review, PermitPulse tracks it. Follow any permit, company, county, or renewal deadline and get an alert within a day of the TCEQ update.
This chapter summarizes publicly available TCEQ guidance for general informational purposes only — it is not legal, engineering, or professional advice. Thresholds and rule citations are drawn from TCEQ's Air Permitting Fact Sheet (RG-616) and the de minimis rule at 30 TAC §116.119, and may change; always confirm requirements against the current TCEQ rules before acting.