ISO 817:2014

Overview

ISO 817:2014 - Refrigerants - Designation and safety classification establishes a clear, internationally accepted system for naming refrigerants and classifying their safety. The standard defines an unambiguous numbering/designation scheme and a harmonized safety classification based on toxicity and flammability data. It also specifies methods to determine key exposure and hazard limits such as the refrigerant concentration limit (RCL) and acute-toxicity exposure limit (ATEL) and includes tables of refrigerant designations, safety classes and concentration limits.

Key Topics

• Refrigerant designation system
  • Numeric rules that map refrigerant numbers to molecular composition (digits indicate number of F, H, C atoms and double bonds).
  • Use of letters (e.g., B or I) for bromine/iodine and the prefix C for cyclic compounds.
• Safety classification
  • Classification based on measured toxicity and flammability parameters.
  • Definitions and test-based metrics: LC50, ALC, EC50, NOAEL, LOAEL.
• Flammability parameters
  • Lower flammability limit (LFL) and elevated temperature flame limit (ETFL).
  • Burning velocity and propagation tests used to determine flammability categories.
• Exposure and concentration limits
  • RCL (maximum safe concentration in air considering toxicity, asphyxiation, flammability).
  • ATEL and occupational exposure concepts (TLV-TWA, WEEL) referenced for risk assessment.
• Blend considerations
  • Definitions for azeotropes/zeotropes, worst-case formulation (WCF) and fractionation effects on toxicity/flammability.
• Supporting tables and symbols
  • Mandatory tables listing assigned refrigerant numbers, compositions and associated RCLs/safety classes.

Applications

ISO 817:2014 is practical and widely used by:

• Refrigerant manufacturers - for consistent product designation and labeling.
• HVAC/R system designers and OEMs - to select compatible refrigerants and design safe systems.
• Safety and compliance teams - to assess risks, prepare safety data sheets (SDS) and meet regulatory requirements.
• Testing laboratories - to perform and report toxicity and flammability measurements in a standardized way.
• Regulators, transporters and installers - for classification, storage, transport and emergency response planning.

Practical uses include refrigerant selection, leak-response planning, workplace exposure assessment, product datasheets, system documentation and regulatory reporting.

Related Standards

ISO 817:2014 sits within ISO/TC 86 (Refrigeration and air-conditioning) work. It complements other ISO and national standards on HVAC safety, refrigerant handling, and material specifications (see national regulations and industry guidance for linked documents).

Keywords: ISO 817:2014, refrigerant designation, refrigerant safety classification, RCL, ATEL, LFL, flammability limits, HVAC safety standards.