Overview
ISO 22899-3:2025 - Determination of the resistance to jet fires of passive fire protection materials, Part 3: Extended test requirements - defines an extended fire-test method that evaluates how passive fire protection (PFP) materials, systems and critical process control equipment (CPCE) behave under severe jet-fire exposure. It is complementary to ISO 22899-1 and is intended for situations where the standard test (Part 1) cannot be applied because of required fire conditions, specimen size or configuration. The document provides performance data for severe jets (indicative sustained heat flux up to 350 kW/m²) but explicitly does not assess other material properties such as weathering, ageing, impact, explosion resistance or smoke production.
Key topics and technical requirements
- Scope and purpose: Extended procedures for larger or non‑standard specimens and for CPCE testing when Part 1 is unsuitable.
- Test configurations: Includes options for specimens mounted in the rear wall of the flame compartment or positioned approximately in the compartment centre; covers panel specimens, structural steelwork, tubular sections and CPCE.
- Test apparatus & conditions: Detailed requirements for nozzle geometry/position, fuel, test environment, temperature rise rates and minimum sustained temperatures, and use of added air where applicable.
- Instrumentation: Specification of fire control thermocouples (wire and cube types), specimen thermocouples and other measurement locations required for reliable data.
- Specimen construction & conditioning: Guidance on substrates, thickness control, density and conditioning of PFP materials and assemblies (e.g., cable transit and pipe penetration systems).
- Performance criteria & reporting: Criteria for pass/fail, repeatability/reproducibility guidance, uncertainty of measurement and required contents of the test report (annexed example report and classification guidance included).
- Limitations: Clarifies which properties are outside the scope and identifies factors affecting test validity (e.g., interruption of the jet fire, thermocouple failures, compartment failures).
Applications and who uses this standard
ISO 22899-3:2025 is used to generate credible, repeatable data on how PFP materials and systems perform in extreme jet-fire scenarios. Typical users include:
- Manufacturers of intumescent coatings, insulating wraps, penetration seals and other PFP products - for product development and certification.
- Independent fire-test laboratories - to run extended jet‑fire tests and issue test reports.
- Operators and engineers in oil & gas, petrochemical, LNG and process industries - for risk assessment and protective system selection.
- Regulators, classification societies and certification bodies - when evaluating PFP performance against severe jet‑fire hazards.
Related standards
- ISO 22899-1 (Jet fire test - basic requirements) - Part 3 is complementary and used when Part 1 is not applicable.
- ISO 22899 series (other parts) and ISO/TC 92 guidance on fire resistance and test methods.
Keywords: ISO 22899-3:2025, jet fires, passive fire protection, PFP materials, extended test requirements, critical process control equipment, fire testing, fire resistance, ISO standard.