ISO 7203-1:2019

Overview

ISO 7203-1:2019 - Fire extinguishing media - Foam concentrates - Part 1 specifies the essential properties and performance requirements for low‑expansion foam concentrates intended for top application to water‑immiscible liquids (Class B fires). The third edition (2019) defines minimum performance on standardized test fires and establishes physical, chemical and performance tests that foam concentrate manufacturers, testing laboratories and end users rely on.

Key technical topics and requirements

ISO 7203-1:2019 covers laboratory and performance characteristics essential to reliable firefighting foams:

• Scope and definitions: Terms such as low‑expansion (expansion ratio 1–20), foam, concentrate, foam solution, expansion and 25% drainage time are defined.
• Performance testing (test fires): Minimum test‑fire performance requirements and procedures are specified (see Annex G). These address fire control, extinction and inhibition of reignition.
• Physical/chemical properties:
  • Viscosity (Newtonian and pseudo‑plastic testing methods).
  • pH measurements and temperature sensitivity (pH limits are required).
  • Surface tension, interfacial tension and spreading coefficient (methods in Annex E) to assess foam solution interaction with hydrocarbons.
  • Sediment limits before and after ageing (Annex C).
  • Tolerance to freezing and thawing (Annex B).
• Foam characteristics:
  • Expansion and drainage limits and measurement of 25% drainage time (Clause 12, Annex F).
• Marking, packaging and specification sheet: Requirements for labelling, packaging and supplier declaration of characteristic values (Clause 14).
• Applicability notes: Suitable for top application to water‑immiscible liquids; foams conforming to ISO 7203‑3 are additionally suitable for water‑miscible liquids. Use in non‑aspirating sprayers or subsurface application may be possible, but specific requirements for those uses are outside the scope.
• Compatibility and informative tests: Annex I addresses compatibility of concentrates and compatibility with powders; Annex J covers small‑scale fire tests.

Practical applications - who uses this standard

ISO 7203‑1:2019 is used by:

• Foam concentrate manufacturers for product development, quality control and compliance claims.
• Independent testing laboratories conducting fire and physical tests.
• Fire protection engineers and system designers specifying foam for refineries, petrochemical plants, terminals, airports, marine and industrial facilities.
• Regulatory bodies, procurement teams and safety managers evaluating foam concentrate performance and suitability for top‑application firefighting systems.

Related standards

• ISO 7203‑2 (medium/high expansion concentrates)
• ISO 7203‑3 (low‑expansion for water‑miscible liquids)
• ISO 7076 (foam systems specification)
• ISO 304 / ISO 3104 / ISO 3219 (test methods referenced for physical measurements)

Keywords: ISO 7203-1:2019, foam concentrates, low-expansion foam, water-immiscible liquids, fire extinguishing media, expansion, drainage, surface tension, test fire performance.