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Standards / ASTM E2768
ASTM E2768
Thirty-minute Steiner tunnel test for extended-duration surface burning. The method ASTM E84 points to when a user needs a 30-minute run. Not a WUI listing and not a noncombustible classification.
Covers: Surface flame spread of a product in the E84 apparatus with the test period extended to 30 minutes, and the classification characteristics codes use for ignition-resistant or fire-retardant-treated wood.
Does not cover: A 10-minute ASTM E84 run treated as a 30-minute result, ASTM E136 noncombustibility, an OSFM listing, or a permit.
ASTM E2768 is the 30-minute Steiner tunnel test method. It uses the ASTM E84 apparatus and procedure with the total test period extended to 30 minutes. It is the document ASTM points to when a user needs an extended-duration surface-burning test. It is not a listing, not noncombustible, and not a permit.
Why it matters
Oregon R327, where adopted, defines ignition-resistant material with a 30-minute tunnel run. Specifiers then write “E84 Class A” on a wall or eave and think they are done. A 10-minute interior-finish result is a different job. This page exists so the 30-minute method has its own record.
How the test works
The store record for the method is titled Standard Test Method for Extended Duration Surface Burning Characteristics of Building Materials (30 min Tunnel Test) (ASTM E2768). Scope 1.1 states the purpose is to evaluate the ability of a product to limit surface spread of flame when evaluated for 30 minutes, using the E84 apparatus and procedure with the period extended.
ASTM also states what the method does not do. It does not measure heat transmission through the tested surface. It does not, by this test or by a flame spread index alone, classify a material as noncombustible. Materials that melt, drip, or delaminate to the point that the flame front is destroyed are beyond its scope.
The published E84 method remains 10 minutes. E84-24 tells users who need a 30-minute duration tunnel test to use E2768. That split is ASTM’s, not this site’s.
The paths
Do not collapse these into one stamp.
| Document | Tunnel duration named | What it decides |
|---|---|---|
| ASTM E84 | 10 minutes | Surface flame spread and smoke for that specimen |
| ASTM E2768 | 30 minutes | Extended-duration surface burning. Codes use the classification characteristics for ignition-resistant or fire-retardant-treated wood |
| Oregon R327 ignition-resistant | E84 or UL 723 extended to 30 minutes | Covering path. The amendment does not print the E2768 number |
| ASTM E136 | Not a tunnel | Noncombustible |
| OSFM 8170 | Handbook notes name extended E84 on some rows | Listing bucket, not this method |
1. Oregon ignition-resistant path. Where R327 is the adopted code, ignition-resistant material is an exterior product tested to ASTM E84 or UL 723 for 30 minutes, flame spread index not more than 25, no significant progressive combustion, and flame front not more than 10.5 feet beyond the burner centerline (amendment PDF). A lab may run that work as E2768. The code section still names E84 or UL 723 extended. Read the report.
2. California ignition-resistant path. 2022 CBC 704A.3 allows the Chapter 7A conditions of acceptance or ASTM E2768. SFM 12-7A-5 is the SFM ignition-resistant material method. Do not treat a 10-minute E84 Class A as that path.
3. Listing path. OSFM category 8170 is ignition-resistant materials. Notes on those rows may name an extended E84 run. That is a listing note, not a substitute for the test report. See OSFM BML.
4. Not noncombustible. ASTM E136 is the noncombustible method Oregon names. OSFM 8175 is a different handbook bucket. Read ignition-resistant versus noncombustible.
What people mix up
- Treating a 10-minute E84 Class A as Oregon ignition-resistant material.
- Calling a flame spread index a noncombustible classification. ASTM says E2768 does not do that.
- Treating an OSFM 8170 ID as the test method.
- Writing “E2768 approved.” This site does not approve products. Listed means a named model has a listing ID.
How to check
Open the test report. Confirm the method number, the duration (30 minutes, not 10), the flame spread index, progressive combustion, and the flame-front distance. Match the specimen to the product you will install.
If the job is Oregon R327, read R327.2 and the covering section that uses ignition-resistant material. If the job is California Chapter 7A or CWUIC, read the ignition-resistant definition in the adopted book.
Limits
This page does not host the ASTM text. It does not decide what the building official will stamp. Absence from the OSFM handbook is not an automatic ban. Presence is not a permit.
Related records
ASTM E84, SFM 12-7A-5, OSFM BML, siding.
Sources
- ASTM E2768 (ASTM International)
- ASTM E84-24 (ASTM International)
- 2023 ORSC Section R327 amendment (Oregon BCD)
- 2022 CBC Chapter 7A (ICC / California)
Is ASTM E2768 the same as ASTM E84?
No. E84 is the 10-minute Steiner tunnel method. E2768 uses that apparatus and procedure with the total test period extended to 30 minutes. ASTM E84-24 tells users who need a 30-minute duration tunnel test to use E2768.
Does an E2768 result make a product noncombustible?
No. ASTM states that E2768 does not classify a material as noncombustible by the results of this method or by a flame spread index alone. Oregon R327 points noncombustible to ASTM E136.
Is E2768 an OSFM listing?
No. E2768 is a test method. OSFM category 8170 is a listing bucket that may name an extended E84 run. Listing, the test, and a permit are three steps.
Does a 10-minute Class A E84 result satisfy Oregon ignition-resistant material?
No. Where R327 is adopted, ignition-resistant material is an exterior product tested to ASTM E84 or UL 723 extended to 30 minutes, with a flame spread index not more than 25, no significant progressive combustion, and a flame front not more than 10.5 feet beyond the burner centerline.