ATLANTA - Eight proposed addenda, including three adding new refrigerant designations, to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) refrigerant safety standard are now open for public review.

ANSI/ASHRAE Standard 34-2004, Designation and Safety Classification of Refrigerants, establishes a simplified means of referring to common refrigerants in place of chemical names, formulas, or trade names. It also establishes safety classifications based on toxicity and flammability data. To read the proposed addenda or to comment, visit

The following addenda are open for public review until Oct. 22:

  • 34d would require refrigerant applications to be submitted in electronic format in addition to printed copies.

  • 34i would add a designation of R-426A to a blend of R-125/134a/600/601a.

  • 34j would add a designation of R-427A to a blend of R-32/125/143a/134a.

  • 34l would add a designation of R-428A to a blend of R-125/143a/290/600a.

    The following addenda are open for review until Nov. 6:

  • 34m would remove the requirement to submit refrigerant property data elements that are not needed in determining the refrigerant designation or safety classifications.

  • 34t would add an informative appendix containing refrigerant data removed from the standard by addendum 34u-2004 and bubble/dew points for azeotropic blends.

  • 34v would update addendum 34u-2004 text and tables based on an increased oxygen depletion concentration level from 69,100 parts per million (ppm) to 140,000 ppm, increased cardiac sensitization default from 0 to 1,000 ppm, new toxicity information for R-22, 32, and 227ea, new lower flammability limit values, and addition of new refrigerants.

  • 34w would add an informative appendix containing toxicity values for single-compound refrigerants, compiling toxicity information from various sources into one table.

    Publication date: 10/09/2006