The three hydrocarbons are:

• R290 (propane),
• R600a (isobutane)
• R441A, a hydrocarbons blend also known as HCR188C

The announcement comes a year and half after the publication of a proposed rule under the EPA’s Significant New Alternatives Policy (SNAP) programme and several years of efforts by end-users such as Unilever, and companies working with hydrocarbons such as A.S. Trust & Holdings, the company that invented refrigerant blend R441A.

“Replacing refrigerants such as CFC-12, HCFC-22, or HFCs will reduce greenhouse gas emissions by an estimated 600,000 metric tons by 2020, equal to the emissions from the annual electricity use of nearly 75,000 homes, and will help protect people’s health and the environment”, reads the US EPA announcement.

Refrigerant charge limits as outlined in proposed rule

The SNAP final rule setting out the requirements for the use of hydrocarbons, including refrigerant charge size limits will only be issued later this week. The proposed rule (May 2010), provides an indication regarding the potential refrigerant charge size limits per refrigerant circuit, with the US EPA proposing levels that would reflect standards UL 250 and UL 471:

• Household refrigerators and freezers: 57grams (2.0 ounces), equivalent to approximately the charge size contained in two disposable lighters, and well below the international household refrigerator and freezers standard’s charge size limit of 150 grams (5.3 ounces)

• Retail food refrigeration in stand-alone units: 150 grams (5.3 ounces), equivalent to approximately the charge size contained in five disposable lighters or less, and in line with the IEC 60335-2-89 standard for commercial appliances, which has a charge size limit of 150 grams (5.3 ounces).

The 57g charge size limit could prove a challenging one to meet, especially considering the large size of typical US refrigerators.

In the unofficial version of the final rule that the US EPA released on 14 December 2011, the Agency is clarifying that charge size limitations apply to each refrigerant circuit in a refrigerator or freezer, not necessarily the entire appliance.

Hydrocarbons in the US: from trials to a wider roll out

Up until now, end users and retailers, including Unilever (Ben & Jerry’s), Nestle, Pepsi, and Fresh & Easy had limited themselves to trials when it comes to the use of hydrocarbons in the US, which they could carry out by receiving exemptions for test-marketing end-use equipment for research and development purposes.

The new SNAP rule will now pave the way for a wider roll-out of hydrocarbons in the US.