How much hydrofluorocarbon (HFC) blowing agent does closed-cell foam lose in its first year and each year after, under the Intergovernmental Panel on Climate Change (IPCC) default?

The IPCC Tier 1 default for closed-cell foam is 10 percent of the original HFC charge lost in the first year, then 4.5 percent a year for 20 more years: 10 plus 20 x 4.5 is 100 percent. The Guidelines warn that methods assuming full release over manufacture and use are likely to significantly over-estimate any given year.

The default and where it comes from

Volume 3 Chapter 7, Table 7.5: product lifetime 20 years, first year losses 10 percent of the original charge ("although the value could drop to 5% if significant recycling takes place during manufacturing") and annual losses 4.5 percent of the original charge. The source is given as Gamlen et al. (1986). The Guidelines say these defaults result in "90 percent of the initial charges being emitted over twenty years of annual use, after the initial 10 percent during the first year". Table 7.5 is the Tier 1a default, for use where the foam application cannot be split into sub-applications and no regional data exist. The Guidelines say that a significant majority of closed-cell emissions occur at or after decommissioning, so methods that assume total release over manufacture and use "are likely to significantly over-estimate emissions for any given year". This default is exactly that kind of method, so treat it as a screening figure.

The full equation

Equation 7.7: Emissions in year t = M(t) x first year loss factor + Bank(t) x annual loss factor + decommissioning losses minus emissions prevented by recovery and destruction. M is the HFC used in new closed-cell foam that year, and the bank is the charge blown into foam in the previous n years, where n is the product life. Open-cell foams lose all of it in year one, so Equation 7.8 is simply Emissions = M.

Where each loss happens

• First-year loss: where the foam is made or installed. For a factory, that is the plant.
• Annual loss: where the product is used, so at your customers.
• Decommissioning: where it is scrapped. The Guidelines say a "significant majority" of closed-cell emissions arise at or after decommissioning, and that methods assuming full release during manufacture and use are likely to over-estimate a given year.

What the Guidelines say not to do

They call the mass-balance approach "inappropriate for foams since there is no mechanism by which such products are serviced in practice". Use the emission-factor approach, and use the sub-application values in our panel page when you know the product type. The tables cover HFC blowing agents only; hydrocarbon agents are not in them.

A plant blowing 20 tonnes of HFC into closed-cell foam in one year

• First-year loss at the plant: 20 x 0.10 = 2.0 tonnes of HFC
• Each of the next 20 years of use: 20 x 0.045 = 0.9 tonnes of HFC a year
• Over 20 years of use: 20 x 0.9 = 18.0 tonnes
• Total: 2.0 + 18.0 = 20.0 tonnes, the full charge
• With 5 percent first-year loss because of recycling in manufacture: 20 x 0.05 = 1.0 tonne in year one

The 20 tonnes is an example. Multiply tonnes by the global warming potential in your chosen report for carbon dioxide equivalent (CO2e).

What Senseible does here

Senseible reads fuel invoices and electricity bills into dated records. It does not read blowing agent purchases, so keep the HFC tonnes in your own sheet and add the line to your inventory.

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Sources: IPCC 2006 Guidelines, Volume 3 Chapter 7 (Section 7.4, Table 7.5, Equations 7.7 and 7.8)

Last reviewed 2026-11-05. These are the Guidelines' generic Tier 1 values. Use the product-type table where you know the foam type.