Senseible

Aerosol cans filled with hydrofluorocarbon (HFC) gas this year: which year do the emissions count in?

It depends on the method. The national equation of the Intergovernmental Panel on Climate Change (IPCC) spreads emissions over two years, by default half of a year's sales in that year and half the next. Category 11 of the Greenhouse Gas (GHG) Protocol counts the full lifetime emissions of units sold in the year of sale.

The IPCC's national equation

Equation 7.6 is: emissions in year t equal the HFC or perfluorocarbon contained in aerosol products sold in year t times the emission factor, plus the amount sold in year t-1 times one minus the emission factor. The factor is the fraction emitted in the first year. For the broad spectrum of aerosol products the default is 50 percent of the initial charge per year, which means half escapes in the first year and the rest in the second.

The IPCC defines the point of sale as sales by the manufacturer to the supply chain, not by the retailer to the end user. So a can leaves your books when you sell it to a distributor, even if it sits on a shelf for months.

The GHG Protocol's rule for a company

Category 11 of the Scope 3 guidance includes the total expected lifetime emissions from all relevant products sold in the reporting year. The IPCC says all of an aerosol's charge escapes within the first year or two. Our reading: for a company report, the whole charge of the cans you sold in the year goes into that year's Category 11, with the share released at 100 percent if you do not know it.

Why the two differ, and which to use

Two years of sales (example figures)

Sales figures are an example. The 50 percent is the IPCC default for aerosol products taken together, used here only to show the timing.

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 aerosol propellant releases from documents, so keep the sales and fill weights yourself.

Sources: IPCC 2006 Guidelines, Volume 3, Chapter 7, Emissions of Fluorinated Substitutes for Ozone Depleting Substances, GHG Protocol Technical Guidance for Calculating Scope 3 Emissions, Category 11 (Formula 11.3)

Last reviewed 2026-11-05. Equation 7.6 and the 50 percent default are from section 7.3 of the IPCC 2006 Guidelines. The reading that a company report should use Category 11 timing is ours; confirm it against the buyer's or standard's rule.