UL 2431 2019-05 PDF

Full title and description

UL 2431 — Durability of Fire-Resistive Coatings and Materials. This standard establishes methods to evaluate the ability of spray-applied and other fire‑resistive materials and coatings to retain their fire‑resistive properties after exposure to environmental and mechanical conditioning (e.g., erosion, salt spray, UV, freeze/thaw, vibration, impact) and subsequent fire testing on representative steel specimens (tubes, wide‑flange sections, plates).

Abstract

UL 2431 defines conditioning procedures and post‑conditioning fire exposure tests (including a normal temperature‑rise fire and a rapid temperature‑rise/ hydrocarbon‑type fire) to assess long‑term durability of protective materials applied to structural elements. The standard is used to determine whether a material maintains thermal‑protective performance after realistic environmental and mechanical stresses.

General information

• Status: Active / Current (Edition 2 with a May 2019 revision; UL maintains redline/revision history and later updates).
• Publication date: Revision published May 2, 2019 (redline noted May 3, 2019); original Edition 2 published October 15, 2014.
• Publisher: Underwriters Laboratories (UL / UL Standards & Engagement).
• ICS / categories: 13.220 — Protection against fire (fire protection test methods and materials).
• Edition / version: Edition 2 (with 2019 revision / redline).
• Number of pages: Generally listed as 36–37 pages depending on the vendor/format (UL Red Line and published PDF listings commonly show 36–37 pages).

Scope

The scope of UL 2431 is to provide standardized test methods to measure the durability of fire‑resistive coatings and materials after they have been subjected to defined environmental and mechanical conditioning. The standard specifies conditioning exposures (air erosion, wet/freeze/dry cycling, humidity, impact, industrial atmosphere, salt spray, temperature stability, ultraviolet light, vibration, etc.) and defines two fire exposure curves — a normal (cellulosic/fully developed) temperature rise and a rapid (hydrocarbon) temperature rise — to evaluate retained fire protection on steel structural elements. It is intended to complement other structural fire protection standards and to inform listing decisions for materials used in harsh service environments.

Key topics and requirements

• Defined conditioning procedures simulating environmental, chemical and mechanical aging (e.g., salt spray, UV, vibration, impact, humidity, freeze/thaw cycles).
• Fire exposure definitions: normal temperature‑rise fire curve and rapid (hydrocarbon) temperature‑rise curve for performance evaluation.
• Test specimens and instrumentation: steel tubes, wide‑flange sections and plates with monitored temperatures to determine protective performance after conditioning.
• Pass/fail criteria and reporting requirements to document retained thermal performance after conditioning and fire exposure.
• Requirements intended to support listing/certification decisions and to be used in conjunction with other UL standards for structural fire protection (for example to inform UL 1709 applications).

Typical use and users

Manufacturers of fire‑resistive coatings and cementitious sprays; third‑party testing laboratories; applicators and contracting firms that install passive fire protection systems; engineering consultants and specifiers; building and petrochemical facility owners and safety authorities who require validated durability data for fire protection materials in harsh environments.

Related standards

UL 2431 is often used alongside other structural fire protection standards and tests, notably UL 1709 (Rapid‑Rise Fire Tests of Protection Materials for Structural Steel) and UL 263 (Fire Tests of Building Construction and Materials). It may also be referenced in product listings and certificates where long‑term environmental durability of fire protection materials is required.

Keywords

durability, fire‑resistive coatings, spray‑applied fireproofing, environmental conditioning, salt spray, ultraviolet, vibration, impact resistance, UL 2431, structural steel protection, fire exposure curves, rapid temperature rise, normal temperature rise.

FAQ

Q: What is this standard?

A: UL 2431 is a UL standard that specifies methods to evaluate the durability of fire‑resistive coatings and materials by subjecting them to environmental and mechanical conditioning followed by fire exposure testing to measure retained protective performance.

Q: What does it cover?

A: It covers conditioning procedures (e.g., erosion, salt spray, UV, humidity, freeze/thaw, impact, vibration), specimen types (steel tubes, wide‑flange sections, plates), and post‑conditioning fire tests (normal and rapid temperature‑rise exposures) to determine whether a material retains acceptable fire‑resistive performance.

Q: Who typically uses it?

A: Coating and material manufacturers, testing laboratories, applicators, specifiers, owners of industrial and commercial facilities, and certification bodies use UL 2431 to demonstrate long‑term durability of passive fire protection products.

Q: Is it current or superseded?

A: Edition 2 is the active edition; a May 2019 revision/redline was issued (commonly cited as May 2–3, 2019). UL maintains revision history and occasional redline updates — users should confirm they have the latest UL Red Line or consolidated edition from UL for current requirements.

Q: Is it part of a series?

A: UL 2431 is part of UL's body of standards addressing structural and material fire protection and is used in conjunction with related UL standards (for example UL 1709 and UL 263) rather than being a numbered-series subpart. It is referenced where environmental durability of listed fire protection materials is required.

Q: What are the key keywords?

A: Durability; fire‑resistive coatings; spray‑applied; environmental conditioning; salt spray; UV; vibration; impact; steel protection; UL 2431.