SIST EN ISO 3679:2023

Overview

EN ISO 3679:2022 (Corrected version 2023-05) specifies methods for determining the flash no‑flash result and the flash point using a small scale closed cup tester. Published by CEN and aligned with ISO 3679:2022, the standard defines three procedures (A, B and C) for rapid equilibrium and automated non‑equilibrium testing across broad temperature ranges and product types.

• Procedures A and B (rapid equilibrium): applicable for paints (including water‑borne), varnishes, binders, adhesives, solvents, petroleum products, aviation turbine/diesel/kerosene fuels and fatty acid methyl esters (FAME) over –30 °C to 300 °C. Procedure A is a flash no‑flash pass/fail test at a specified temperature; Procedure B determines the flash point.
• Procedure C (non‑equilibrium, automated): applicable to petroleum and related products over –20 °C to 300 °C; precision established for 40 °C to 135 °C.

Key Topics and Requirements

• Test principles: rapid equilibrium (A/B) vs automated non‑equilibrium (C) small‑cup closed‑cup techniques.
• Sample volume and speed: small sample sizes (2 ml or 4 ml noted in the standard introduction) and faster test cycles compared with older closed‑cup methods.
• Scope limitations: caution advised for solvent mixtures with halogenated hydrocarbons (possible anomalous results).
• Instrumentation and verification: apparatus design, verification procedures and temperature measuring device specifications are normative (see Annexes A, B and E).
• Special procedures: sub‑ambient testing and the use of cup inserts are covered (Annexes C and D).
• Precision and reporting: precision statements and repeatability/reproducibility are provided (precision tables referenced, e.g., Table 2); Procedures A or B are recommended for specifications and regulatory work.

Applications

EN ISO 3679:2022 is used for:

• Quality control of paints, varnishes, adhesives and solvents.
• Fuel testing for aviation turbine fuels, diesel, kerosene and other petroleum products.
• Biodiesel/FAME testing with appropriate flash detectors.
• On‑site and laboratory testing, as the apparatus can be portable for field checks or used in accredited labs.
• Regulatory compliance and product specification where a small‑scale closed cup method is required.

Who Uses This Standard

• Test laboratories (industrial and third‑party)
• Paint and coatings manufacturers
• Fuel producers and refiners
• Environmental and safety compliance teams
• Product development and QC engineers

Related Standards

• ISO 1516, ISO 1523 (other closed‑cup equilibrium methods)
• IP 534 and ASTM D7236 (procedural basis for automated/non‑equilibrium methods referenced)

EN ISO 3679:2022 is essential for professionals needing a compact, faster closed‑cup method to assess flash behaviour and flash point across a wide range of liquid and semi‑solid products.