Overview
EN ISO 10156:2017 (ISO 10156:2017) - "Gas cylinders - Gases and gas mixtures - Determination of fire potential and oxidizing ability for the selection of cylinder valve outlets" - specifies methods to determine whether a gas or gas mixture is flammable in air and whether it has greater or lesser oxidizing ability than air at atmospheric conditions (20 °C). It is intended primarily for the classification of gases and gas mixtures and for the correct selection of cylinder valve outlets. The standard does not cover safe preparation of pressurised mixtures or conditions other than ambient.
Key topics and requirements
- Flammability in air
- Definitions of flammable gases and lower/upper flammability limits at atmospheric pressure and 20 °C.
- Laboratory test methods and safety considerations for determining if a gas or mixture is ignitable in air.
- Procedures for measuring flammability limits for pure gases and guidance on calculating limits for gas mixtures.
- Oxidizing ability
- Tests and criteria to determine whether a gas or gas mixture is more or less oxidizing than air.
- Test apparatus, procedures and calculation methods to assign oxidizing potential.
- Mixtures containing oxygen
- Specific treatment and calculation approaches where oxygen is present with flammable gases.
- Calculation methods and examples
- Methods for combining data for multiple flammable and inert components, with worked examples to aid classification.
- Classification and labelling
- Guidance compatible with the UN Model Regulations and Globally Harmonized System (GHS) for hazard classification and labelling.
- Scope limits
- Does not include procedures for safe preparation of mixtures under pressure or non-ambient temperatures.
Practical applications
EN ISO 10156:2017 is used by:
- Gas producers and cylinder filling plants - to classify products and select appropriate cylinder valve outlets.
- Cylinder and valve manufacturers - to ensure valve outlet compatibility with gas groups.
- Occupational health & safety professionals - to assess fire and oxidizing hazards during storage, handling and use of industrial gases.
- Regulatory authorities and transport operators - for compliance with transport, labelling and storage rules.
- Test laboratories - for implementing standardised flammability and oxidizing tests and calculations.
Related standards
- ISO 5145 - dimensions of cylinder valve outlets (used together with ISO 10156 for valve selection).
- ISO 14456 - criteria for compatible gas groups.
- UN Model Regulations and GHS - for classification and labelling alignment.
EN ISO 10156:2017 provides a practical, harmonised framework for assessing fire potential and oxidizing power of gases and mixtures - essential for safe cylinder valve selection, consistent labelling, and regulatory compliance in the industrial gases sector.
