# A foam moulding unit uses a hydrofluorocarbon (HFC) blowing agent for integral skin parts or one-component foam: how much escapes, and when?

Canonical: https://senseible.earth/answers/integral-skin-and-one-component-foam-hfc-blowing-agent

For open-cell foams the Intergovernmental Panel on Climate Change (IPCC) treats the HFC blowing agent as lost during manufacture and soon after, so emissions equal the HFC you used. Its tables give a 95 percent first-year loss for integral skin and one-component foam, so counting all of it in the year is the simple reading.

## Which foams the IPCC treats as open-cell

The IPCC says that for open-cell foam, emissions of HFC blowing agents are likely to occur during manufacture and shortly after. It lists household furniture cushioning, mattresses, automotive seating and moulded products such as car steering wheels and office furniture as open-celled uses.

Its table of HFC use in foam blowing marks HFC-134a and HFC-245fa for polyurethane integral skin foam, and HFC-134a and HFC-152a for one-component foam. It marks no HFC for polyurethane flexible foam. So check your recipe: this page applies only if an HFC is really in it. Spray foam is not one of these: the IPCC lists polyurethane spray foam as closed-cell (Table 7.7: 15 percent first year, 1.5 percent a year, 50 years, 10 percent at end of life), so a spray foam rig falls under the closed-cell rows and Equation 7.7, not Equation 7.8.

## The equation

Equation 7.8 is: emissions in year t equal the total HFC used in manufacturing new open-cell foam in year t. It is applied to each chemical separately. For one-component foam, the filled can may be traded, so the gas can be emitted where the can is used rather than where you filled it.

## Where the tables differ from the equation

Tables 7.6 and 7.7 give polyurethane integral skin foam (HFC-134a and HFC-152a in Table 7.6, HFC-245fa in Table 7.7, with the same values) a product life of 12 years, a first-year loss of 95 percent, an annual loss of 2.5 percent and an end-of-life loss of 0. One-component foam has 95 percent, 2.5 percent, a life of 50 years and 0. On the same check, the one-component row sums to 95 + 2.5 x 50 = 220 percent.

Applied to the original charge for the whole life, those numbers do not add up: 95 + 2.5 x 12 = 125 percent for integral skin. Our reading is that the 2.5 percent describes the small remainder leaking out afterwards. The IPCC does not say so. Counting all of the HFC in the year you used it follows Equation 7.8 and, on our reading, can only be slightly high, so it is the safe choice. The IPCC also says the open-cell first-year loss factor is typically 100 percent.

## Where it sits in your report

Reading IPCC for one site (it does not use Scopes): HFC released at your moulding line is a direct emission from a source you control, Scope 1 in Greenhouse Gas (GHG) Protocol terms. For one-component foam cans you sell, the part released at the customer is a use-phase emission of a sold product (GHG Protocol Category 11); that is our reading. Keep invoices for the HFC and a stock count.

## A year of HFC-134a at a moulding unit (example figures)

- HFC used: opening 120 plus purchases 600 minus closing 150 = 570 kilograms
- Equation 7.8: 570 kilograms emitted in the year
- Table 7.6 split for integral skin: 95 percent in year one = 541.5 kilograms; 5 percent = 28.5 kilograms left (541.5 + 28.5 = 570)
- Multiply the kilograms by the global warming potential of the HFC you use

Stock and purchase figures are an example. The 95 percent and 5 percent split is shown only to compare with the equation.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into a dated, fingerprinted record, so the fuel and power of the site show up once uploaded. It does not calculate blowing agent releases from documents, so work that line out from your own gas records.

- [Foam panel and appliance foam blowing agent losses](https://senseible.earth/answers/pu-panel-and-appliance-foam-hfc-loss-by-type)
- [Carbon footprint of a foam mattress](https://senseible.earth/answers/foam-mattress-carbon-footprint-per-unit)
- [Which assessment report's global warming potential values to use](https://senseible.earth/answers/ar5-vs-ar6-gwp-which-to-use)
- [What Senseible does not calculate](https://senseible.earth/answers/what-emissions-senseible-does-not-calculate)

Sources: [IPCC 2006 Guidelines, Volume 3, Chapter 7, Emissions of Fluorinated Substitutes for Ozone Depleting Substances](https://www.ipcc-nggip.iges.or.jp/public/2006gl/pdf/3_Volume3/V3_7_Ch7_ODS_Substitutes.pdf)

Last reviewed 2026-11-05. From section 7.4 and Tables 7.4 and 7.6 of the IPCC 2006 Guidelines. Many foam recipes use no HFC; confirm the blowing agent with your chemical supplier before applying this page.