ISO 10156:2017 PDF

Overview

ISO 10156:2017 - Gas cylinders - Gases and gas mixtures - Determination of fire potential and oxidizing ability for the selection of cylinder valve outlets specifies standardized methods to determine whether a gas or gas mixture is flammable in air and whether it is more or less oxidizing than air under atmospheric conditions (101.3 kPa, 20 °C). The standard is used for classification of gases and gas mixtures, including the selection of cylinder valve outlets, and supports transport and GHS classification decisions. It does not cover safe preparation of mixtures under pressure or at non-ambient temperatures.

Key technical topics and requirements

• Flammability testing and calculation

  • Provides a quiescent tube test: mix the gas with air, ignite (electric spark) and observe whether a flame propagates.
  • Specifies test preparation: use representative “most flammable” composition, moisture ≤ 0.01 %, and gas analysis (chromatograph or oxygen/flammable gas detectors).
  • Defines lower and upper flammability limits (LFL/UFL) and the flammability range at atmospheric conditions.
  • Offers a calculation method for mixtures using reliable T (or L) values; where test and calculation differ, the test result takes precedence.

• Oxidizing ability

  • Introduces oxidizing power (OP) as a dimensionless metric - calculated as the sum of mole fraction of each oxidizing component multiplied by its oxygen-equivalency coefficient (Ci).
  • Gives both test and calculation procedures to establish whether a mixture is more oxidizing than air (reference = 23.5 % O2 in N2).

• Safety and procedural controls

  • Tests must be performed by trained personnel with PPE; reaction tube and flowmeter must be screened to protect against explosion.
  • Compressed air and test mixtures require careful analysis and moisture control.

• Regulatory alignment

  • Intended for use with the UN Model Regulations and UN-GHS; includes guidance on GHS classification. Non-flammable UN designations override calculations.

Practical applications and users

Who uses ISO 10156:2017:

• Cylinder and valve manufacturers selecting appropriate valve outlets (see ISO 5145 linkage).
• Industrial gas suppliers and formulators assessing gas mixture hazards.
• Safety engineers, transport regulators, and compliance officers preparing classification, labeling, and transport documentation.
• Testing laboratories performing flammability/oxidizing assessments for certification and GHS classification.

Typical applications:

• Determining valve outlet compatibility to prevent unsafe cylinder connections.
• Establishing flammability/oxidizing data for SDS, transport documents, and hazard communication.
• Supporting conformity with transport and hazardous goods regulations.

Related standards and references

• ISO 5145 (cylinder valve outlet dimensions)
• ISO 14456 (criteria for compatible gas groups)
• Test-method references: EN 1839, ASTM E681
• UN Model Regulations and UN-GHS for classification and transport labeling

Keywords: ISO 10156:2017, gas cylinders, flammability limits, oxidizing ability, cylinder valve outlets, gas mixtures, GHS classification, oxidizing power.