UL 867 is the Standard for Electrostatic Air Cleaners, and a listing to it is an electrical safety credential — nothing in its scope addresses how much grease an electrostatic precipitator takes out of a kitchen exhaust stream. That gap matters because the phrase that reaches most buyers is simply “UL certified,” which gets read as a blanket pass. This page sets out what the scope actually says, the three things it states it does not cover, and how to check a File Number yourself in about five minutes.
This guide helps you decide whether a UL 867 listing supports the conclusion you need it to support.
It does not select or size equipment, quote a price, or make any compliance determination for your project.
For product-specific review, see the in-duct electrostatic precipitator page and our certificate scope.
| Document | Product scope | What it supports | What it does not prove |
|---|---|---|---|
| UL 867 Electrostatic Air Cleaners Edition 5, revised 2026-06-29 |
Electrostatic air cleaners rated 600 V or less, used per the NEC (ANSI/NFPA 70) | Electrical safety of the listed models, maintained under Follow-Up Service | Grease removal efficiency · installation compliance · use in hazardous locations |
What UL 867 covers
The scope is short and worth reading in the original rather than in summary. Clause 1.1 reads:
These requirements cover electrostatic air cleaners rated at 600 volts or less, intended to remove dust and other particles from the air and intended for use in accordance with the National Electrical Code, ANSI/NFPA 70.
Two things follow from that sentence. The subject is the electrostatic precipitator itself and its electrical behavior, and the reference point is the National Electrical Code. Grease, airflow, capture rate and duct conditions do not appear anywhere in the scope, because they are not what this document is about.
Clause 1.1.1 extends the standard to products powered from a low-voltage source, to certain battery-powered household portables, and to units provided with ultraviolet lamp systems in which the UV wavelengths are 200 nm or greater. That last condition is a threshold worth noting if a quotation bundles a UV stage with the precipitator: the wavelength decides whether that stage can be assessed under this standard at all.
Edition and revision matter more than buyers expect. Edition 5 is active, the most recent revision is dated June 29, 2026, and ANSI approval carries the same date; Editions 3 and 4 are archived. The standard has been revised repeatedly — 2024, 2023, 2021, 2018, 2016 and earlier. A file assessed against an older edition is not automatically re-assessed when the text changes, so “listed to UL 867” and “listed to the current edition of UL 867” are different statements.
The three things it states it does not cover
Most of the value in this standard, for a buyer, is in the exclusions. They are written plainly.
| Clause | What it excludes | What that means for your project |
|---|---|---|
| 1.2 | Air cleaners for use in hazardous locations, or to clean atmospheres defined as hazardous by the NEC | If your process area is classified, this listing does not reach it — raise the classification with the supplier before the model is selected |
| 1.3 | Air cleaners intended to remove particles other than dust and other particles normally found in heating and ventilating systems | The standard is framed around HVAC service, so treat any capture claim for your specific process as a separate evidence question |
| 1.4 | Installation requirements — these sit in NFPA 90A and NFPA 90B | Route, access, clearance and enclosure are settled on drawings against those standards and your local mechanical code, not by the listing |
This table answers what the standard excludes. It does not answer which document covers each excluded item in your jurisdiction; that depends on the codes your authority has adopted.
On ozone: requirements relating to it sit in the body of the standard rather than in the published scope, and the full text is a paid document. We are not going to quote a limit we have not read in the original. What we would do in your position is ask the supplier for a written statement of the ozone requirement their model was assessed against, and treat a figure offered without that reference as unverified.
Verify a File Number yourself
This is the part a supplier cannot do for you, and it takes about five minutes. Work through it on any supplier you are considering, including us.
| Step | Do this | What good looks like | Record |
|---|---|---|---|
| 1 | Ask for the File Number, in the form E######, rather than a certificate image | The supplier gives the number without hesitation | File No. ________ |
| 2 | Look the number up in UL Product iQ | An entry exists under that file | Found / not found |
| 3 | Read the model list on the entry | The model on your quotation appears on it | Quoted model ______ listed? Y / N |
| 4 | Check the listing is maintained under Follow-Up Service | The file is active, not lapsed | Active? Y / N |
| 5 | Ask which edition the assessment was against | A specific edition, not just “UL 867” | Edition ______ |
| 6 | Write the exclusions into your purchase notes | Efficiency, installation and hazardous locations are logged as separate evidence | Logged? Y / N |
A listing scope is not a company claim
A file is granted to named models. That means every listing has a model list, and the list is the thing that decides whether the certificate applies to the unit on your quotation.
Here is ours, so the shape of the answer is concrete. Polygee holds UL 867 Listed status under File E522667, covering the LK and SE 6K, 12K and 18K models, maintained through UL Follow-Up Service. We build 102 electrostatic precipitator models, so that listing reaches three of them. Our other lines are covered by other documents with their own scopes, set out on the certificates page.
A listing covering three models is worth precisely what it says. The useful question is never whether a supplier holds UL 867, but which of their models the file names — and any supplier who reads their own certificate can answer that in one line.
UL 867 is not UL 710, and not a performance test
Three documents get folded together in kitchen exhaust conversations. They act on different objects.
| Document | Object | Answers | Does not answer |
|---|---|---|---|
| UL 867 | The electrostatic air cleaner itself | Electrical safety of the listed models | How much grease it captures |
| UL 710 / 710B | The exhaust hood | What a listed hood proves about exhaust rate and clearance — set out in UL 710B vs UL 710 | Anything about equipment inside the duct |
| A third-party efficiency report | Collection performance at a stated airflow | What was measured, under which method, at which flow | Electrical safety, or results at other airflows |
The efficiency question needs its own document. Our LK in-duct units measured up to 97.6% grease removal in CMA-accredited third-party tests under report ZY05W230298. Request the report itself and check the serial-number link and test conditions before treating any efficiency figure as a performance basis — ours included. A UL file will never carry that number, because it is not what a UL file is for.
Separately, an ESP installed in line with a commercial grease duct brings a further set of code requirements about listing, access, drainage and downstream fire protection. Those are set out in grease duct requirements rather than here.
Where this guide stops
Three layers of evidence are routinely confused, and clearing one does not clear the next.
- Equipment evidence. A listing and a test report describe named models under stated conditions. Passing one layer does not clear the next.
- Site installation and interfaces. Clause 1.4 sends installation to NFPA 90A and 90B, and a commercial kitchen adds its own mechanical code requirements on top. Settle these on drawings, with the unit shown in the run.
- Whole-system operation. What an installed ESP achieves depends on capture at the hood, the process actually run and maintenance. No listing settles this in advance, so agree at handover how it will be checked.
This page summarizes a published standard’s scope for planning purposes. It is not a compliance determination, and the edition in force in your jurisdiction is a question for your engineer and the authority having jurisdiction.
Buyer record
- Request from the supplier: the File Number · the model list under it · the edition assessed against · Follow-Up Service status · a written ozone statement · the separate efficiency report with its number and test airflow.
- Verify yourself: the file in UL Product iQ, and your quoted model against its list.
- Log as separate evidence: efficiency, installation compliance and any hazardous-area classification.
- Triggers a re-check: a model substitution, a change of target market, a revised standard edition, or a change in the area classification of the space.
Key takeaways
- Subject: judge UL 867 as an electrical safety standard, not as a performance one.
- Scope: judge by the model list in the file, not by the phrase on a home page.
- Installation: judge by NFPA 90A and 90B plus your mechanical code, not by the listing.
- Edition: judge by the edition assessed, not by the standard number alone.
- Efficiency: judge by a test report with its airflow stated, which is a different document entirely.
Frequently Asked Questions
- What does UL 867 cover?
- UL 867 is the Standard for Electrostatic Air Cleaners. Its scope covers electrostatic air cleaners rated at 600 volts or less, intended to remove dust and other particles from the air and intended for use in accordance with the National Electrical Code, ANSI/NFPA 70. It is an electrical safety standard: nothing in its scope addresses how much grease a unit removes.
- Does a UL 867 listing prove grease removal efficiency?
- No. Collection performance is established by a test report that states the airflow and the method used, not by an electrical safety listing. Treat the two as separate documents and ask for both. Our own LK in-duct units measured up to 97.6% grease removal in CMA-accredited third-party tests under report ZY05W230298, and that report, not the UL file, is what supports the figure.
- Are installation requirements part of UL 867?
- No. Clause 1.4 of the scope places installation requirements for duct-type electrostatic air cleaners in NFPA 90A, the Standard for the Installation of Air Conditioning and Ventilating Systems, and NFPA 90B for warm air heating and air conditioning systems. A listed unit installed badly is still installed badly, and the listing does not speak to it.
- How do I check whether a UL file actually covers the model I am quoted?
- Ask for the File Number rather than a certificate image, then look it up in UL Product iQ and read the model list on the entry. If the model on your quotation is not on that list, the file does not cover it. Our listing, File E522667, covers the LK and SE 6K, 12K and 18K models, which is three of the 102 models we build.
- Which edition of UL 867 is current?
- Edition 5 is the active edition, with the most recent revision dated June 29, 2026 and ANSI approval on the same date. Editions 3 and 4 are archived. Because the standard is revised regularly, ask a supplier which edition their file was assessed against rather than assuming the listing tracks the newest text automatically.
Ask for the file
Checking an electrostatic precipitator against a specification? Send us the model you have been quoted, your design airflow and your target market, and we will come back with the File Number and the models it names, the edition assessed, the separate third-party efficiency report with the airflow it was measured at, and a plain statement of which documents do not apply. You get back a set of references you can verify without us.
Request the file references →Why we write this
We build in-duct electrostatic precipitators and hood-integrated units, and we hold a UL 867 listing on part of that range. The question that reaches us most often is some version of “is it UL certified,” which is a question the file itself answers only partly. This page sets out the scope in the standard’s own words so the answer can be checked rather than taken on trust. It does not size or configure equipment; sizing and quotation live on the product pages.
Law manages commercial kitchen exhaust filtration projects at Polygee, from specification review through duct-side sizing and installation support. Polygee, founded in 2004, designs and builds commercial kitchen exhaust filtration equipment and holds UL 867 Listed status under File E522667 for part of its range. Certificates and test reports referenced here are available on request. This article summarizes a published standard for planning purposes and is not a compliance determination.
References & further reading
- UL Standards & Engagement — UL 867, Standard for Electrostatic Air Cleaners, Edition 5, revised June 29, 2026. Scope clauses 1.1–1.4 as published. shopulstandards.com
- National Fire Protection Association — NFPA 90A, Standard for the Installation of Air-Conditioning and Ventilating Systems. nfpa.org
- National Fire Protection Association — NFPA 90B, Standard for the Installation of Warm Air Heating and Air-Conditioning Systems. nfpa.org
Related reading
- Commercial kitchen ESP buying guide — the six documents to ask any supplier for, of which the UL file is one.
- UL 710B vs UL 710 — the hood listings, and why they answer a different question.
- Certificates — the model list behind each document we hold.
- Grease duct requirements — what the code asks once a unit sits in the duct run.