ANSI/ASHRAE Standard 34-2004, which supersedes Standard 34-2001, describes a shorthand way of naming refrigerants and assigns safety classifications based on toxicity and flammability data. The 2004 edition combines Standard 34-2001 and the twelve approved and published addenda to the 2001 edition, thereby providing an easy-to-use consolidated standard.

This standard is intended to establish a simple means of referring to common refrigerants instead of using the chemical name, formula, or trade name. It also establishes a uniform system for assigning reference numbers and safety classifications to refrigerants. The standard identifies requirements to apply for designations and safety classifications for refrigerants, including blends, in addenda or revisions to this standard.

This standard provides an unambiguous system for numbering refrigerants and assigning composition-designating prefixes for refrigerants. Safety classifications based on toxicity and flammability data are included. This standard does not imply endorsement or concurrence that individual refrigerant blends are suitable for any particular application.

Units: Dual