ISO 817:2024

International
Standard
ISO 817
Fourth edition
Refrigerants — Designation and
2024-11
safety classification
Fluides frigorigènes — Désignation et classification de sécurité
Reference number
© ISO 2024
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Published in Switzerland
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Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, abbreviated terms and symbols . 1
3.1 Terms and definitions .1
3.2 Abbreviated terms .6
3.3 Symbols .7
4 Numbering of refrigerants . 7
4.1 Refrigerant Tables .7
4.2 Identifying numbers .8
4.2.1 General .8
4.2.2 First digit on the right.8
4.2.3 Second digit from the right .8
4.2.4 Third digit from the right .8
4.2.5 Fourth digit from the right .8
4.2.6 Presence of bromine (Br) or iodine (I) .8
4.2.7 Number of chlorine (Cl) atoms .8
4.2.8 Carbon atoms . .8
4.2.9 Cyclic compounds .8
4.2.10 Isomers in the ethane and ethene series .9
4.2.11 Isomers in the propane series .9
4.2.12 Isomers in the propene series.9
4.2.13 Extension to compounds of four carbon atoms .10
4.2.14 Identification of stereoisomers .10
4.3 Ether-based refrigerants .10
4.3.1 General .10
4.3.2 Two-carbon, dimethyl ethers .10
4.3.3 Straight chain, three carbon ethers . .10
4.3.4 Cyclic ethers .11
4.4 Blends .11
4.4.1 General .11
4.4.2 Zeotropes .11
4.4.3 Azeotropes .11
4.4.4 Blend tolerances . .11
4.4.5 Composition uniqueness . 12
4.5 Miscellaneous organic compounds . 12
4.6 Inorganic compounds . 13
4.6.1 General . 13
4.6.2 Compounds with relative molar masses less than 100 . 13
4.6.3 Compounds with relative molar masses equal to or greater than 100 . 13
4.6.4 Two or more inorganic refrigerants with the same molar masses . 13
5 Designation prefixes .13
5.1 General prefixes . 13
5.2 Composition-designating prefixes . 13
6 Safety classifications . 14
6.1 General .14
6.1.1 Safety classification — Composition .14
6.1.2 Toxicity classification . .14
6.1.3 Flammability classification . 15
6.2 Matrix diagram of safety group classification system.16
7 Refrigerant classifications and property data . 17
8 Refrigerant concentration limits . 17

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8.1 General .17
8.1.1 General .17
8.1.2 Acute-toxicity exposure limit (ATEL) .17
8.1.3 Mortality .17
8.1.4 Cardiac sensitization .18
8.1.5 Anaesthetic or central nervous system (CNS) effects .18
8.1.6 Other escape-impairing symptoms and permanent injury .19
8.1.7 Oxygen deprivation limit (ODL) .19
8.2 Data for calculations .19
8.2.1 Data sources .19
8.2.2 Consistent measures . 20
8.3 Contaminants and impurities . 20
8.4 Conversion of units — Volumic mass and altitude adjustment . 20
Annex A (informative) Examples of isomer designation .21
Annex B (normative) Details of testing for flammability and fractionation analysis .23
Annex C (normative) Refrigerant classifications and properties .27
Annex D (normative) Calculation of ATEL for blends .28
Annex E (informative) Data used to determine safety classification, refrigerant concentration
limits and data for unclassified refrigerants .31
Annex F (informative) Examples of minimum composition tolerance .32
Bibliography .34

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