ASHRAE has published ANSI/ASHRAE Standard 34-2001, Designation and Safety Classification of Refrigerants. The standard establishes a simple 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.

Standard 34-2001 incorporates the 1997 standard as well as 17 previously approved addenda. The standard is published on a three-year cycle to coincide with the deadlines for adoption by major building code organizations.

"The standard now contains all addenda in one document, which makes it more convenient and easier to use," Steve Szymurski, chair of the Standard 34 committee, said.

Among the addenda incorporated are five new addenda, 34m, 34n, 34r, 34s and 34t. These addenda add designations and safety classifications for R414B, R416A, and R417A; change the safety classification of R245fa to B1; and change the composition tolerances for R402A and R402B.