What you need to know about the Environment Protection Agency’s proposed Rule 20

Formulating for the Next Generation HFO Blowing Agents in North America?
Learn how Air Products can help

HFC Blowing Agents are under pressure to be phased out

USA - In support of President Obama’s 2013 Climate Action Plan, the Environmental Protection Agency (EPA) has proposed Significant New Alternatives Policy (SNAP) Program Rule 20 to de-list Hydrofluorocabrons (HFCs) such as HFC-245fa, HFC-365mfc, and HFC-134a from use within specific foam applications.  The new Rule 20 goes into effect on August 19, 2015.  It restricts use of HFCs or blends thereof as early as January 1, 2017.  Rigid Spray Foam remains “not finalized”.

Canada - Environment Canada has also proposed an HFC phase down proposal in parallel to the EPA ruling. Its phase down approach, starting January 2017, which prohibits use of HFCs in:
  • Spray Foam Applications by January 2019
  • Extruded polystyrene by January 2020
  • All other foams by January 2022

Next Generation HFO Blowing Agents

In response to these HFC phase-out proposals (now rulings), new alternatives have come into place. The Hydrofluoroolefins (HFOs) HFO-1233zd(e) and HFO-1336mzz(z) are both new, low global warming potential (GWP) blowing agents designed to meet the new EPA and Environment Canada specifications.

However, these new HFO blowing agents have a chemical structure that breaks down quickly, resulting in an atmospheric lifetime of weeks rather than years or decades.  This class of chemical is a “fourth-generation” family of compounds, developed to replace a long line of similar substances that had high ODP or GWP.  

Air Products has been a leader in enabling new blowing agent technologies and continues to do so with this new generation 

Introducing Polycat® 204 Catalyst, a non-emissive amine catalyst specially designed to deliver high-end results when used with both HFO-1233zd(e) and HFO-1336zz(z).  Polycat 204, in combination with these products, can help customers achieve between 6 to 8 months of B-side stability with HFO-1233zd(e).

Foam rate chart

Typical uses levels of Polycat 204 are 2% to 4% by weight.  The product can be used with other catalysts to optimize system stability, overall reactivity as well as back-end cure speed.  Recommended co-catalysts for HFO based systems include: Dabco 2040, Dabco TMR20, Dabco MB20, Dabco T120, and Dabco T125.

Below is a guide to using Polycat 204 in a way that best fits your system and needs. 


HFO Blowing Agent Regulation Brochure 2015
Download PDF (2,873 KB)

POLYCAT® 201 Catalyst, CPI 2013
Download PDF (972 KB)

POLYCAT® 203 Catalyst
Download PDF (195 KB)

POLYCAT® 204 Catalyst
Download PDF (195 KB)

Polyurethane Additives Guide
Download PDF (9 MB) - North, Central and South America
Download PDF (3 MB) - Europe, Middle East, Africa
Download PDF (1 MB) - Asia

Or please contact your local technical sales representative for more information. 


POLYCAT® 201 Catalyst, CPI 2013
Download PDF (972 KB)


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